계: Input Validation and Representation

입력 검증 및 표현 문제는 메타 문자, 대체 인코딩 및 숫자 표현 때문에 발생합니다. 보안 문제는 입력을 신뢰하기 때문에 발생합니다. 문제로는 "Buffer Overflows", "Cross-Site Scripting" 공격, "SQL Injection", 그 외 여러 가지가 있습니다.

Cross-Site Scripting: Handlebars Helper

Abstract
검증되지 않은 데이터를 웹 브라우저에 보내면 브라우저가 악성 코드를 실행하는 결과를 초래할 수 있습니다.
Explanation
XSS(Cross-Site Scripting) 취약점은 다음 경우에 발생합니다.

1. 신뢰할 수 없는 소스를 통해 데이터가 웹 응용 프로그램에 입력됩니다. Handlebars를 사용하면 템플릿을 수정하는 데 사용할 수 있는 사용자 지정 도우미를 만들 수 있습니다.


2. 데이터는 검증 없이 웹 사용자에게 전달된 동적 컨텐츠에 포함됩니다. Handlebars 도우미의 경우, 악성 컨텐츠가 템플릿의 출력으로 렌더링됩니다.

Handlebars 도우미에 있는 악성 컨텐츠는 JavaScript 세그먼트 형식이거나 브라우저에서 실행되는 기타 코드 유형입니다. Handlebars 템플릿의 출력은 일반적으로 브라우저에 전달될 HTML 컨텐츠이므로 악의적일 가능성이 있는 컨텐츠는 안전하지 않은 것으로 처리하고 유효성을 검사해야 합니다.

예제 1: 다음과 같은 Handlebars 도우미 코드를 고려하십시오.


Handlebars.registerHelper('bolden', function (aString) {
  return new Handlebars.SafeString("" + aString + "")
})
// ...
let template = Handlebars.compile('{{bolden someArgument}}')
myElem.innerHTML = template({someArgument: userInput})
bolden 도우미에는 사용자 제어 데이터 userInput이 전달됩니다. 이중 중괄호({{ 및 }})의 사용은 일반적으로 출력이 HTML로 인코딩됨을 의미하지만 이 시나리오에서 bolden 도우미는 입력을 new Handlebars.SafeString()에 전달하여 모든 유효성 검사가 무시되므로 입력이 일반 HTML로 렌더링됩니다. template()에서 HTML이 반환되면 innerHTML 속성으로 전달되어 DOM 기반 XSS 공격이 야기됩니다.
References
[1] Understanding Malicious Content Mitigation for Web Developers CERT
[2] HTML 4.01 Specification W3
[3] Standards Mapping - Common Weakness Enumeration CWE ID 79, CWE ID 80
[4] Standards Mapping - Common Weakness Enumeration Top 25 2019 [2] CWE ID 079
[5] Standards Mapping - Common Weakness Enumeration Top 25 2020 [1] CWE ID 079
[6] Standards Mapping - Common Weakness Enumeration Top 25 2021 [2] CWE ID 079
[7] Standards Mapping - Common Weakness Enumeration Top 25 2022 [2] CWE ID 079
[8] Standards Mapping - Common Weakness Enumeration Top 25 2023 [2] CWE ID 079
[9] Standards Mapping - Common Weakness Enumeration Top 25 2024 [1] CWE ID 079
[10] Standards Mapping - DISA Control Correlation Identifier Version 2 CCI-001310, CCI-002754
[11] Standards Mapping - FIPS200 SI
[12] Standards Mapping - General Data Protection Regulation (GDPR) Indirect Access to Sensitive Data
[13] Standards Mapping - NIST Special Publication 800-53 Revision 4 SI-10 Information Input Validation (P1)
[14] Standards Mapping - NIST Special Publication 800-53 Revision 5 SI-10 Information Input Validation
[15] Standards Mapping - OWASP Application Security Verification Standard 4.0 5.3.3 Output Encoding and Injection Prevention Requirements (L1 L2 L3), 5.3.6 Output Encoding and Injection Prevention Requirements (L1 L2 L3)
[16] Standards Mapping - OWASP Mobile 2014 M7 Client Side Injection
[17] Standards Mapping - OWASP Mobile 2024 M4 Insufficient Input/Output Validation
[18] Standards Mapping - OWASP Top 10 2004 A4 Cross Site Scripting
[19] Standards Mapping - OWASP Top 10 2007 A1 Cross Site Scripting (XSS)
[20] Standards Mapping - OWASP Top 10 2010 A2 Cross-Site Scripting (XSS)
[21] Standards Mapping - OWASP Top 10 2013 A3 Cross-Site Scripting (XSS)
[22] Standards Mapping - OWASP Top 10 2017 A7 Cross-Site Scripting (XSS)
[23] Standards Mapping - OWASP Top 10 2021 A03 Injection
[24] Standards Mapping - Payment Card Industry Data Security Standard Version 1.1 Requirement 6.5.4
[25] Standards Mapping - Payment Card Industry Data Security Standard Version 1.2 Requirement 6.3.1.1, Requirement 6.5.1
[26] Standards Mapping - Payment Card Industry Data Security Standard Version 2.0 Requirement 6.5.7
[27] Standards Mapping - Payment Card Industry Data Security Standard Version 3.0 Requirement 6.5.7
[28] Standards Mapping - Payment Card Industry Data Security Standard Version 3.1 Requirement 6.5.7
[29] Standards Mapping - Payment Card Industry Data Security Standard Version 3.2 Requirement 6.5.7
[30] Standards Mapping - Payment Card Industry Data Security Standard Version 3.2.1 Requirement 6.5.7
[31] Standards Mapping - Payment Card Industry Data Security Standard Version 4.0 Requirement 6.2.4
[32] Standards Mapping - Payment Card Industry Data Security Standard Version 4.0.1 Requirement 6.2.4
[33] Standards Mapping - Payment Card Industry Software Security Framework 1.0 Control Objective 4.2 - Critical Asset Protection
[34] 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
[35] 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
[36] Standards Mapping - SANS Top 25 2009 Insecure Interaction - CWE ID 079
[37] Standards Mapping - SANS Top 25 2010 Insecure Interaction - CWE ID 079
[38] Standards Mapping - SANS Top 25 2011 Insecure Interaction - CWE ID 079
[39] Standards Mapping - Security Technical Implementation Guide Version 3.1 APP3510 CAT I, APP3580 CAT I
[40] Standards Mapping - Security Technical Implementation Guide Version 3.4 APP3510 CAT I, APP3580 CAT I
[41] Standards Mapping - Security Technical Implementation Guide Version 3.5 APP3510 CAT I, APP3580 CAT I
[42] Standards Mapping - Security Technical Implementation Guide Version 3.6 APP3510 CAT I, APP3580 CAT I
[43] Standards Mapping - Security Technical Implementation Guide Version 3.7 APP3510 CAT I, APP3580 CAT I
[44] Standards Mapping - Security Technical Implementation Guide Version 3.9 APP3510 CAT I, APP3580 CAT I
[45] Standards Mapping - Security Technical Implementation Guide Version 3.10 APP3510 CAT I, APP3580 CAT I
[46] Standards Mapping - Security Technical Implementation Guide Version 4.2 APSC-DV-002490 CAT I, APSC-DV-002560 CAT I
[47] Standards Mapping - Security Technical Implementation Guide Version 4.3 APSC-DV-002490 CAT I, APSC-DV-002560 CAT I
[48] Standards Mapping - Security Technical Implementation Guide Version 4.4 APSC-DV-002490 CAT I, APSC-DV-002560 CAT I
[49] Standards Mapping - Security Technical Implementation Guide Version 4.5 APSC-DV-002490 CAT I, APSC-DV-002560 CAT I
[50] Standards Mapping - Security Technical Implementation Guide Version 4.6 APSC-DV-002490 CAT I, APSC-DV-002560 CAT I
[51] Standards Mapping - Security Technical Implementation Guide Version 4.7 APSC-DV-002490 CAT I, APSC-DV-002560 CAT I
[52] Standards Mapping - Security Technical Implementation Guide Version 4.8 APSC-DV-002490 CAT I, APSC-DV-002560 CAT I
[53] Standards Mapping - Security Technical Implementation Guide Version 4.9 APSC-DV-002490 CAT I, APSC-DV-002560 CAT I
[54] Standards Mapping - Security Technical Implementation Guide Version 4.10 APSC-DV-002490 CAT I, APSC-DV-002560 CAT I
[55] Standards Mapping - Security Technical Implementation Guide Version 4.11 APSC-DV-002490 CAT I, APSC-DV-002560 CAT I
[56] Standards Mapping - Security Technical Implementation Guide Version 4.1 APSC-DV-002490 CAT I, APSC-DV-002560 CAT I
[57] Standards Mapping - Security Technical Implementation Guide Version 5.1 APSC-DV-002490 CAT I, APSC-DV-002560 CAT I
[58] Standards Mapping - Security Technical Implementation Guide Version 5.2 APSC-DV-002490 CAT I, APSC-DV-002560 CAT I
[59] Standards Mapping - Security Technical Implementation Guide Version 5.3 APSC-DV-002490 CAT I, APSC-DV-002530 CAT II, APSC-DV-002560 CAT I
[60] Standards Mapping - Security Technical Implementation Guide Version 6.1 APSC-DV-002490 CAT I, APSC-DV-002530 CAT II, APSC-DV-002560 CAT I
[61] Standards Mapping - Web Application Security Consortium Version 2.00 Cross-Site Scripting (WASC-08)
[62] Standards Mapping - Web Application Security Consortium 24 + 2 Cross-Site Scripting
desc.dataflow.javascript.cross_site_scripting_handlebars_helper