Kingdom: Input Validation and Representation

Input validation and representation problems ares caused by metacharacters, alternate encodings and numeric representations. Security problems result from trusting input. The issues include: "Buffer Overflows," "Cross-Site Scripting" attacks, "SQL Injection," and many others.

NoSQL Injection: Realm

Objective-C
Swift

Abstract

Constructing a dynamic Realm query with input that comes from an untrusted source could allow an attacker to modify the statement's meaning.

Explanation

NoSQL injection in Realm weaknesses occur when:

1. Data enters a program from an untrusted source.

2. The data is used to dynamically construct a Realm query.

Example 1: The following code dynamically constructs and executes a Realm query that searches for an email with a specific ID.


...
    NSString *emailId = [self getEmailIdFromUser];
    NSString *query = [NSString stringWithFormat:@"id == '%@'", emailId];
    RLMResults<Email *> *emails = [Email objectsInRealm:realm where:query];
...

The query intends to execute the following code:


    id == '<emailId value>'

However, because the query is constructed dynamically by concatenating a constant base query string and a user input string, the query only behaves correctly if emailId does not contain a single-quote character. If an attacker enters the string 123' or '4' != '5 for emailId, then the query becomes the following:


    id == '123' or '4' != '5'

The addition of the or '4' != '5' condition causes the where clause to always evaluate to true, which would result in the query returning all entries stored in the emails collection, regardless of the email owner.

References

[1] Standards Mapping - Common Weakness Enumeration CWE ID 89, CWE ID 943

[2] Standards Mapping - Common Weakness Enumeration Top 25 2019 [6] CWE ID 089

[3] Standards Mapping - Common Weakness Enumeration Top 25 2020 [6] CWE ID 089

[4] Standards Mapping - Common Weakness Enumeration Top 25 2021 [6] CWE ID 089

[5] Standards Mapping - Common Weakness Enumeration Top 25 2022 [3] CWE ID 089

[6] Standards Mapping - Common Weakness Enumeration Top 25 2023 [3] CWE ID 089

[7] Standards Mapping - DISA Control Correlation Identifier Version 2 CCI-001310, CCI-002754

[8] Standards Mapping - FIPS200 SI

[9] Standards Mapping - General Data Protection Regulation (GDPR) Indirect Access to Sensitive Data

[10] Standards Mapping - NIST Special Publication 800-53 Revision 4 SI-10 Information Input Validation (P1)

[11] Standards Mapping - NIST Special Publication 800-53 Revision 5 SI-10 Information Input Validation

[12] Standards Mapping - OWASP Application Security Verification Standard 4.0 5.3.4 Output Encoding and Injection Prevention Requirements (L1 L2 L3), 5.3.5 Output Encoding and Injection Prevention Requirements (L1 L2 L3)

[13] Standards Mapping - OWASP Mobile 2014 M7 Client Side Injection

[14] Standards Mapping - OWASP Mobile 2024 M4 Insufficient Input/Output Validation

[15] Standards Mapping - OWASP Mobile Application Security Verification Standard 2.0 MASVS-CODE-4

[16] Standards Mapping - OWASP Top 10 2004 A6 Injection Flaws

[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 - Payment Card Industry Data Security Standard Version 1.1 Requirement 6.5.6

[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 - SANS Top 25 2009 Insecure Interaction - CWE ID 089

[34] Standards Mapping - SANS Top 25 2010 Insecure Interaction - CWE ID 089

[35] Standards Mapping - SANS Top 25 2011 Insecure Interaction - CWE ID 089

[36] Standards Mapping - Security Technical Implementation Guide Version 3.1 APP3510 CAT I, APP3540.1 CAT I, APP3540.3 CAT II

[37] Standards Mapping - Security Technical Implementation Guide Version 3.4 APP3510 CAT I, APP3540.1 CAT I, APP3540.3 CAT II

[38] Standards Mapping - Security Technical Implementation Guide Version 3.5 APP3510 CAT I, APP3540.1 CAT I, APP3540.3 CAT II

[39] Standards Mapping - Security Technical Implementation Guide Version 3.6 APP3510 CAT I, APP3540.1 CAT I, APP3540.3 CAT II

[40] Standards Mapping - Security Technical Implementation Guide Version 3.7 APP3510 CAT I, APP3540.1 CAT I, APP3540.3 CAT II

[41] Standards Mapping - Security Technical Implementation Guide Version 3.9 APP3510 CAT I, APP3540.1 CAT I, APP3540.3 CAT II

[42] Standards Mapping - Security Technical Implementation Guide Version 3.10 APP3510 CAT I, APP3540.1 CAT I, APP3540.3 CAT II

[43] Standards Mapping - Security Technical Implementation Guide Version 4.2 APSC-DV-002540 CAT I, APSC-DV-002560 CAT I

[44] Standards Mapping - Security Technical Implementation Guide Version 4.3 APSC-DV-002540 CAT I, APSC-DV-002560 CAT I

[45] Standards Mapping - Security Technical Implementation Guide Version 4.4 APSC-DV-002540 CAT I, APSC-DV-002560 CAT I

[46] Standards Mapping - Security Technical Implementation Guide Version 4.5 APSC-DV-002540 CAT I, APSC-DV-002560 CAT I

[47] Standards Mapping - Security Technical Implementation Guide Version 4.6 APSC-DV-002540 CAT I, APSC-DV-002560 CAT I

[48] Standards Mapping - Security Technical Implementation Guide Version 4.7 APSC-DV-002540 CAT I, APSC-DV-002560 CAT I

[49] Standards Mapping - Security Technical Implementation Guide Version 4.8 APSC-DV-002540 CAT I, APSC-DV-002560 CAT I

[50] Standards Mapping - Security Technical Implementation Guide Version 4.9 APSC-DV-002540 CAT I, APSC-DV-002560 CAT I

[51] Standards Mapping - Security Technical Implementation Guide Version 4.10 APSC-DV-002540 CAT I, APSC-DV-002560 CAT I

[52] Standards Mapping - Security Technical Implementation Guide Version 4.11 APSC-DV-002540 CAT I, APSC-DV-002560 CAT I

[53] Standards Mapping - Security Technical Implementation Guide Version 4.1 APSC-DV-002540 CAT I, APSC-DV-002560 CAT I

[54] Standards Mapping - Security Technical Implementation Guide Version 5.1 APSC-DV-002540 CAT I, APSC-DV-002560 CAT I

[55] Standards Mapping - Security Technical Implementation Guide Version 5.2 APSC-DV-002540 CAT I, APSC-DV-002560 CAT I

[56] Standards Mapping - Security Technical Implementation Guide Version 5.3 APSC-DV-002530 CAT II, APSC-DV-002540 CAT I, APSC-DV-002560 CAT I

[57] Standards Mapping - Security Technical Implementation Guide Version 6.1 APSC-DV-002530 CAT II, APSC-DV-002540 CAT I, APSC-DV-002560 CAT I

[58] Standards Mapping - Web Application Security Consortium Version 2.00 SQL Injection (WASC-19)

[59] Standards Mapping - Web Application Security Consortium 24 + 2 SQL Injection

desc.dataflow.objc.nosql_injection_realm

Abstract

Constructing a dynamic Realm query with input that comes from an untrusted source could allow an attacker to modify the statement's meaning.

Explanation


...
    let emailId = getFromUser("emailId")
    let email = realm.objects(Email.self).filter("id == '" + emailId + "'")
...

The query intends to execute the following code:


    id == '<emailId value>'


    id == '123' or '4' != '5'

The addition of the or '4' != '5' condition causes the filter clause to always evaluate to true, which would result in the query returning all entries stored in the emails collection, regardless of the email owner.