界: Input Validation and Representation

输入验证与表示问题是由元字符、交替编码和数字表示引起的。安全问题源于信任输入。这些问题包括：“Buffer Overflows”、“Cross-Site Scripting”攻击、“SQL Injection”等其他问题。

Possible Variable Overwrite: Functional Scope

Abstract

此程序会调用可覆盖当前作用域中变量的函数，这可能会为攻击者打开方便之门。

Explanation

对于可覆盖当前作用域中已初始化的变量的函数，攻击者能够通过它影响依赖被覆盖变量的代码的执行情况。
示例 1：如果攻击者为下面这段 PHP 代码中的 str 提供恶意值，则对 parse_str() 的调用可能会覆盖当前作用域中的所有任意变量，包括 first。在这种情况下，如果包含 JavaScript 的恶意值覆盖 first，则该程序会很容易受到 cross-site scripting 攻击。


<?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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