Kingdom: Code Quality
Poor code quality leads to unpredictable behavior. From a user's perspective that often manifests itself as poor usability. For an attacker it provides an opportunity to stress the system in unexpected ways.
Unreleased Resource: Files
Abstract
The program can potentially fail to release a file handle.
Explanation
The program can potentially fail to release a file handle.
Resource leaks have at least two common causes:
- Error conditions and other exceptional circumstances.
- Confusion over which part of the program is responsible for releasing the resource.
Most unreleased resource issues result in general software reliability problems. However, if an attacker can intentionally trigger a resource leak, the attacker may be able to launch a denial of service attack by depleting the resource pool.
Example 1: The following method never closes the file handle it opens. The
Resource leaks have at least two common causes:
- Error conditions and other exceptional circumstances.
- Confusion over which part of the program is responsible for releasing the resource.
Most unreleased resource issues result in general software reliability problems. However, if an attacker can intentionally trigger a resource leak, the attacker may be able to launch a denial of service attack by depleting the resource pool.
Example 1: The following method never closes the file handle it opens. The
finalize()
method for ZipFile
eventually calls close()
, but there is no guarantee as to how long it will take before the finalize()
method will be invoked. In a busy environment, this can result in the JVM using up all of its file handles.Example 2: Under normal conditions, the following fix properly closes the file handle after printing out all the zip file entries. But if an exception occurs while iterating through the entries, the zip file handle will not be closed. If this happens often enough, the JVM can still run out of available file handles.
public void printZipContents(String fName) throws ZipException, IOException, SecurityException, IllegalStateException, NoSuchElementException {
ZipFile zf = new ZipFile(fName);
Enumeration<ZipEntry> e = zf.entries();
while (e.hasMoreElements()) {
printFileInfo(e.nextElement());
}
}
public void printZipContents(String fName) throws ZipException, IOException, SecurityException, IllegalStateException, NoSuchElementException {
ZipFile zf = new ZipFile(fName);
Enumeration<ZipEntry> e = zf.entries();
while (e.hasMoreElements()) {
printFileInfo(e.nextElement());
}
zf.close();
}
References
[1] FIO04-J. Release resources when they are no longer needed CERT
[2] DOS-2: Release resources in all cases Oracle
[3] Standards Mapping - Common Weakness Enumeration CWE ID 775
[4] Standards Mapping - Common Weakness Enumeration Top 25 2019 [21] CWE ID 772
[5] Standards Mapping - DISA Control Correlation Identifier Version 2 CCI-001094
[6] Standards Mapping - NIST Special Publication 800-53 Revision 4 SC-5 Denial of Service Protection (P1)
[7] Standards Mapping - NIST Special Publication 800-53 Revision 5 SC-5 Denial of Service Protection
[8] Standards Mapping - OWASP Top 10 2004 A9 Application Denial of Service
[9] Standards Mapping - Payment Card Industry Data Security Standard Version 1.1 Requirement 6.5.9
[10] Standards Mapping - Payment Card Industry Data Security Standard Version 3.0 Requirement 6.5.6
[11] Standards Mapping - Payment Card Industry Data Security Standard Version 3.1 Requirement 6.5.6
[12] Standards Mapping - Payment Card Industry Data Security Standard Version 3.2 Requirement 6.5.6
[13] Standards Mapping - Payment Card Industry Data Security Standard Version 3.2.1 Requirement 6.5.6
[14] Standards Mapping - Payment Card Industry Data Security Standard Version 4.0 Requirement 6.2.4
[15] Standards Mapping - Payment Card Industry Software Security Framework 1.0 Control Objective 4.2 - Critical Asset Protection
[16] Standards Mapping - Payment Card Industry Software Security Framework 1.1 Control Objective 4.2 - Critical Asset Protection
[17] Standards Mapping - Payment Card Industry Software Security Framework 1.2 Control Objective 4.2 - Critical Asset Protection, Control Objective C.3.3 - Web Software Attack Mitigation
[18] Standards Mapping - SANS Top 25 2009 Risky Resource Management - CWE ID 404
[19] Standards Mapping - Security Technical Implementation Guide Version 3.1 APP6080 CAT II
[20] Standards Mapping - Security Technical Implementation Guide Version 3.4 APP6080 CAT II
[21] Standards Mapping - Security Technical Implementation Guide Version 3.5 APP6080 CAT II
[22] Standards Mapping - Security Technical Implementation Guide Version 3.6 APP6080 CAT II
[23] Standards Mapping - Security Technical Implementation Guide Version 3.7 APP6080 CAT II
[24] Standards Mapping - Security Technical Implementation Guide Version 3.9 APP6080 CAT II
[25] Standards Mapping - Security Technical Implementation Guide Version 3.10 APP6080 CAT II
[26] Standards Mapping - Security Technical Implementation Guide Version 4.2 APSC-DV-002400 CAT II
[27] Standards Mapping - Security Technical Implementation Guide Version 4.3 APSC-DV-002400 CAT II
[28] Standards Mapping - Security Technical Implementation Guide Version 4.4 APSC-DV-002400 CAT II
[29] Standards Mapping - Security Technical Implementation Guide Version 4.5 APSC-DV-002400 CAT II
[30] Standards Mapping - Security Technical Implementation Guide Version 4.6 APSC-DV-002400 CAT II
[31] Standards Mapping - Security Technical Implementation Guide Version 4.7 APSC-DV-002400 CAT II
[32] Standards Mapping - Security Technical Implementation Guide Version 4.8 APSC-DV-002400 CAT II
[33] Standards Mapping - Security Technical Implementation Guide Version 4.9 APSC-DV-002400 CAT II
[34] Standards Mapping - Security Technical Implementation Guide Version 4.10 APSC-DV-002400 CAT II
[35] Standards Mapping - Security Technical Implementation Guide Version 4.11 APSC-DV-002400 CAT II
[36] Standards Mapping - Security Technical Implementation Guide Version 4.1 APSC-DV-002400 CAT II
[37] Standards Mapping - Security Technical Implementation Guide Version 5.1 APSC-DV-002400 CAT II
[38] Standards Mapping - Security Technical Implementation Guide Version 5.2 APSC-DV-002400 CAT II
[39] Standards Mapping - Security Technical Implementation Guide Version 5.3 APSC-DV-002400 CAT II
[40] Standards Mapping - Web Application Security Consortium Version 2.00 Denial of Service (WASC-10)
[41] Standards Mapping - Web Application Security Consortium 24 + 2 Denial of Service
desc.controlflow.java.unreleased_resource_files