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。

Denial of Service: StringBuilder

Java/JSP
Kotlin

Abstract

將不受信任的資料附加至使用預設支援陣列大小初始化的 StringBuilder 或 StringBuffer 執行個體，可能會導致 JVM 過度消耗堆積記憶體空間。

Explanation

將使用者控制的資料附加至使用預設支援字元陣列大小 (16) 初始化的 StringBuilder 或 StringBuffer 執行個體，可能會導致應用程式在調整基礎陣列大小以適合使用者資料時消耗大量的堆積記憶體。將資料附加至 StringBuilder 或 StringBuffer 執行個體時，執行個體會判斷支援字元陣列是否有足夠空間來儲存資料。如果資料不適合，則 StringBuilder 或 StringBuffer 執行個體會建立新陣列並使其陣列大小為先前的至少兩倍，同時，舊陣列將在記憶體回收之前保留在堆積中。攻擊者可使用此實作詳細資料執行 Denial of Service (DoS) 攻擊。

範例 1：使用者控制的資料已附加至使用預設建構函式初始化的 StringBuilder 執行個體。


    ...
    StringBuilder sb = new StringBuilder();
    final String lineSeparator = System.lineSeparator();
    String[] labels = request.getParameterValues("label");
    for (String label : labels) {
        sb.append(label).append(lineSeparator);
    }
    ...

References

[1] DOS-1: Beware of activities that may use disproportionate resources Oracle

[2] MSC05-J. Do not exhaust heap space CERT

[3] Standards Mapping - DISA Control Correlation Identifier Version 2 CCI-001094, CCI-001310

[4] Standards Mapping - NIST Special Publication 800-53 Revision 4 SC-5 Denial of Service Protection (P1), SI-10 Information Input Validation (P1)

[5] Standards Mapping - NIST Special Publication 800-53 Revision 5 SC-5 Denial of Service Protection, SI-10 Information Input Validation

[6] Standards Mapping - OWASP API 2023 API4 Unrestricted Resource Consumption

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

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

[9] Standards Mapping - OWASP Top 10 2004 A9 Application Denial of Service

[10] Standards Mapping - Payment Card Industry Data Security Standard Version 1.1 Requirement 6.5.1

[11] Standards Mapping - Payment Card Industry Data Security Standard Version 2.0 Requirement 6.5.1

[12] Standards Mapping - Payment Card Industry Data Security Standard Version 3.0 Requirement 6.5.1

[13] Standards Mapping - Payment Card Industry Data Security Standard Version 3.1 Requirement 6.5.6

[14] Standards Mapping - Payment Card Industry Data Security Standard Version 3.2 Requirement 6.5.6

[15] Standards Mapping - Payment Card Industry Data Security Standard Version 3.2.1 Requirement 6.5.6

[16] Standards Mapping - Payment Card Industry Data Security Standard Version 4.0 Requirement 6.2.4

[17] Standards Mapping - Payment Card Industry Data Security Standard Version 4.0.1 Requirement 6.2.4

[18] Standards Mapping - Payment Card Industry Software Security Framework 1.0 Control Objective 4.2 - Critical Asset Protection

[19] 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

[20] 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

[21] Standards Mapping - SANS Top 25 2010 Risky Resource Management - CWE ID 754

[22] Standards Mapping - Security Technical Implementation Guide Version 3.1 APP3510 CAT I

[23] Standards Mapping - Security Technical Implementation Guide Version 3.4 APP3510 CAT I

[24] Standards Mapping - Security Technical Implementation Guide Version 3.5 APP3510 CAT I

[25] Standards Mapping - Security Technical Implementation Guide Version 3.6 APP3510 CAT I

[26] Standards Mapping - Security Technical Implementation Guide Version 3.7 APP3510 CAT I

[27] Standards Mapping - Security Technical Implementation Guide Version 3.9 APP6080 CAT II

[28] Standards Mapping - Security Technical Implementation Guide Version 3.10 APP6080 CAT II

[29] Standards Mapping - Security Technical Implementation Guide Version 4.2 APSC-DV-002400 CAT II

[30] Standards Mapping - Security Technical Implementation Guide Version 4.3 APSC-DV-002400 CAT II

[31] Standards Mapping - Security Technical Implementation Guide Version 4.4 APSC-DV-002400 CAT II

[32] Standards Mapping - Security Technical Implementation Guide Version 4.5 APSC-DV-002400 CAT II

[33] Standards Mapping - Security Technical Implementation Guide Version 4.6 APSC-DV-002400 CAT II

[34] Standards Mapping - Security Technical Implementation Guide Version 4.7 APSC-DV-002400 CAT II

[35] Standards Mapping - Security Technical Implementation Guide Version 4.8 APSC-DV-002400 CAT II

[36] Standards Mapping - Security Technical Implementation Guide Version 4.9 APSC-DV-002400 CAT II

[37] Standards Mapping - Security Technical Implementation Guide Version 4.10 APSC-DV-002400 CAT II

[38] Standards Mapping - Security Technical Implementation Guide Version 4.11 APSC-DV-002400 CAT II

[39] Standards Mapping - Security Technical Implementation Guide Version 4.1 APSC-DV-002400 CAT II

[40] Standards Mapping - Security Technical Implementation Guide Version 5.1 APSC-DV-002400 CAT II

[41] Standards Mapping - Security Technical Implementation Guide Version 5.2 APSC-DV-002400 CAT II

[42] Standards Mapping - Security Technical Implementation Guide Version 5.3 APSC-DV-002400 CAT II, APSC-DV-002530 CAT II

[43] Standards Mapping - Security Technical Implementation Guide Version 6.1 APSC-DV-002400 CAT II, APSC-DV-002530 CAT II

[44] Standards Mapping - Web Application Security Consortium Version 2.00 Denial of Service (WASC-10)

desc.dataflow.java.denial_of_service_stringbuilder

Abstract

將不受信任的資料附加至使用預設支援陣列大小初始化的 StringBuilder 或 StringBuffer 執行個體，可能會導致 JVM 過度消耗堆積記憶體空間。

Explanation


    ...
    val sb = StringBuilder()
    val labels = request.getParameterValues("label")
    for (label in labels) {
        sb.appendln(label)
    }
    ...