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。

Possible Variable Overwrite: Functional Scope

Abstract

此程式會呼叫可在目前範圍中覆寫變數的函數，但也等於是為攻擊者製造機會。

Explanation

函數若可覆寫在目前範圍中初始化的變數，則也會讓攻擊者得以影響依賴已覆寫變數的程式碼執行。
範例 1：若攻擊者在以下 PHP 程式碼區段中為 str 提供惡意值，則呼叫 parse_str() 時可能會在目前範圍中覆寫包括 first 在內的任意變數。在此案例中，若包含 JavaScript 的惡意值覆寫 first，此程式會容易受到 Cross-Site Scripting 攻擊。


<?php
    $first="User";
    ...
    $str =  $_SERVER['QUERY_STRING'];
    parse_str($str);
    echo $first;
?>

References

[1] Standards Mapping - Common Weakness Enumeration CWE ID 473

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

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

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

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

[6] Standards Mapping - Payment Card Industry Data Security Standard Version 3.0 Requirement 6.5.6

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

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

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

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

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

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

[13] 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

[14] 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

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

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

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