界: Input Validation and Representation

輸入驗證和表示法問題是由中繼字元、替代編碼和數值表示法引起的。信任輸入會導致安全問題。問題包括：「Buffer Overflows」、「Cross-Site Scripting」攻擊、「SQL Injection」及其他許多問題。

NoSQL Injection: Realm

Objective-C
Swift

Abstract

透過使用不可信賴來源的輸入建構動態 Realm 查詢可讓攻擊者修改陳述式的意義。

Explanation

NoSQL injection in Realm 弱點會在以下情況中出現：

1.資料從一個不可信賴的來源進入程式。

2.資料用來動態建構 Realm 查詢。

範例 1：以下程式碼會動態建構並執行 Realm 查詢，該查詢可搜尋含有指定 ID 的電子郵件。


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

此查詢欲執行以下程式碼：


    id == '<emailId value>'

但是，由於這個查詢是連續固定基礎查詢字串和使用者輸入字串所動態建構而成的，所以只有在 emailId 沒有包含單引號字元的時候，查詢才會正確執行。如果攻擊者為 emailId 輸入字串 123' or '4' != '5，那麼查詢將會變更為：


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

附加條件 or '4' != '5' 會使 where 子句的評估永遠為 True，所以不論電子郵件擁有者為何，此查詢均會傳回 emails 集合中儲存的所有項目。

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 - Common Weakness Enumeration Top 25 2024 [3] CWE ID 089

[8] Standards Mapping - DISA Control Correlation Identifier Version 2 CCI-001310, 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 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)

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

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

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

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

[18] Standards Mapping - OWASP Top 10 2007 A2 Injection Flaws

[19] Standards Mapping - OWASP Top 10 2010 A1 Injection

[20] Standards Mapping - OWASP Top 10 2013 A1 Injection

[21] Standards Mapping - OWASP Top 10 2017 A1 Injection

[22] Standards Mapping - OWASP Top 10 2021 A03 Injection

[23] Standards Mapping - Payment Card Industry Data Security Standard Version 1.1 Requirement 6.5.6

[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 Data Security Standard Version 4.0.1 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 - SANS Top 25 2009 Insecure Interaction - CWE ID 089

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

desc.dataflow.objc.nosql_injection_realm

Abstract

透過使用不可信賴來源的輸入建構動態 Realm 查詢可讓攻擊者修改陳述式的意義。

Explanation


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

此查詢欲執行以下程式碼：


    id == '<emailId value>'


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

附加條件 or '4' != '5' 會使 filter 子句的評估永遠為 True，所以不論電子郵件擁有者為何，此查詢均會傳回 emails 集合中儲存的所有項目。