界: Environment

本节包括的所有内容均与源代码无关，但对所创建产品的安全性仍然至关重要。因为本节涉及的问题与源代码没有直接关系，所以我们将它与其他章节分开。

Weak XML Schema: Unbounded Occurrences

Universal

Abstract

将 maxOccurs 值设置为 unbounded 可能导致资源枯竭，最终引发 Denial of Service 攻击。

Explanation

处理 XML 文档的计算成本可能十分高昂。攻击者可以向应用程序提供大量元素，促使应用程序耗尽系统资源，从而利用允许无限量元素的架构。

以下是允许无限量 bar 元素的架构示例。


<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema" >
  <xs:element name="foo" >
    <xs:complexType>
      <xs:sequence>
	<xs:element name="bar" maxOccurs="unbounded" />
      </xs:sequence>
    </xs:complexType>
  </xs:element>
</xs:schema>

References

[1] XML Schema Part 1: Structures Second Edition W3C

[2] Roger L. Costello Constrain the Number of Occurrences of Elements in your XML Schema

[3] Standards Mapping - Common Weakness Enumeration CWE ID 400, CWE ID 770

[4] Standards Mapping - Common Weakness Enumeration Top 25 2019 [20] CWE ID 400

[5] Standards Mapping - Common Weakness Enumeration Top 25 2020 [23] CWE ID 400

[6] Standards Mapping - Common Weakness Enumeration Top 25 2022 [23] CWE ID 400

[7] Standards Mapping - Common Weakness Enumeration Top 25 2024 [24] CWE ID 400

[8] Standards Mapping - DISA Control Correlation Identifier Version 2 CCI-001094, CCI-001310, CCI-002385

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

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

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

[12] Standards Mapping - OWASP API 2023 API8 Security Misconfiguration

[13] Standards Mapping - OWASP Application Security Verification Standard 4.0 8.1.4 General Data Protection (L2 L3), 11.1.3 Business Logic Security Requirements (L1 L2 L3), 11.1.4 Business Logic Security Requirements (L1 L2 L3), 12.1.1 File Upload Requirements (L1 L2 L3), 12.1.3 File Upload Requirements (L2 L3), 13.2.4 RESTful Web Service Verification Requirements (L2 L3)

[14] Standards Mapping - OWASP Mobile 2014 M1 Weak Server Side Controls

[15] Standards Mapping - OWASP Mobile 2024 M8 Security Misconfiguration

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

[17] Standards Mapping - OWASP Top 10 2010 A6 Security Misconfiguration

[18] Standards Mapping - OWASP Top 10 2013 A5 Security Misconfiguration

[19] Standards Mapping - OWASP Top 10 2017 A6 Security Misconfiguration

[20] Standards Mapping - OWASP Top 10 2021 A05 Security Misconfiguration

[21] Standards Mapping - Payment Card Industry Data Security Standard Version 1.1 Requirement 6.5.9

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

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

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

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

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

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

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

[29] Standards Mapping - Payment Card Industry Software Security Framework 1.1 Control Objective 4.2 - Critical Asset Protection

[30] Standards Mapping - Payment Card Industry Software Security Framework 1.2 Control Objective 4.2 - Critical Asset Protection

[31] Standards Mapping - SANS Top 25 2010 Risky Resource Management - CWE ID 770

[32] Standards Mapping - Security Technical Implementation Guide Version 3.1 APP6080 CAT II

[33] Standards Mapping - Security Technical Implementation Guide Version 3.4 APP6080 CAT II

[34] Standards Mapping - Security Technical Implementation Guide Version 3.5 APP6080 CAT II

[35] Standards Mapping - Security Technical Implementation Guide Version 3.6 APP6080 CAT II

[36] Standards Mapping - Security Technical Implementation Guide Version 3.7 APP6080 CAT II

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

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

[39] Standards Mapping - Security Technical Implementation Guide Version 4.2 APSC-DV-002390 CAT II, APSC-DV-002400 CAT II, APSC-DV-002550 CAT I

[40] Standards Mapping - Security Technical Implementation Guide Version 4.3 APSC-DV-002390 CAT II, APSC-DV-002400 CAT II, APSC-DV-002550 CAT I

[41] Standards Mapping - Security Technical Implementation Guide Version 4.4 APSC-DV-002390 CAT II, APSC-DV-002400 CAT II, APSC-DV-002550 CAT I

[42] Standards Mapping - Security Technical Implementation Guide Version 4.5 APSC-DV-002390 CAT II, APSC-DV-002400 CAT II, APSC-DV-002550 CAT I

[43] Standards Mapping - Security Technical Implementation Guide Version 4.6 APSC-DV-002390 CAT II, APSC-DV-002400 CAT II, APSC-DV-002550 CAT I

[44] Standards Mapping - Security Technical Implementation Guide Version 4.7 APSC-DV-002390 CAT II, APSC-DV-002400 CAT II, APSC-DV-002550 CAT I

[45] Standards Mapping - Security Technical Implementation Guide Version 4.8 APSC-DV-002390 CAT II, APSC-DV-002400 CAT II, APSC-DV-002550 CAT I

[46] Standards Mapping - Security Technical Implementation Guide Version 4.9 APSC-DV-002390 CAT II, APSC-DV-002400 CAT II, APSC-DV-002550 CAT I

[47] Standards Mapping - Security Technical Implementation Guide Version 4.10 APSC-DV-002390 CAT II, APSC-DV-002400 CAT II, APSC-DV-002550 CAT I

[48] Standards Mapping - Security Technical Implementation Guide Version 4.11 APSC-DV-002390 CAT II, APSC-DV-002400 CAT II, APSC-DV-002550 CAT I

[49] Standards Mapping - Security Technical Implementation Guide Version 4.1 APSC-DV-002390 CAT II, APSC-DV-002400 CAT II, APSC-DV-002550 CAT I

[50] Standards Mapping - Security Technical Implementation Guide Version 5.1 APSC-DV-002390 CAT II, APSC-DV-002400 CAT II, APSC-DV-002550 CAT I

[51] Standards Mapping - Security Technical Implementation Guide Version 5.2 APSC-DV-002390 CAT II, APSC-DV-002400 CAT II, APSC-DV-002550 CAT I

[52] Standards Mapping - Security Technical Implementation Guide Version 5.3 APSC-DV-002390 CAT II, APSC-DV-002400 CAT II, APSC-DV-002550 CAT I

[53] Standards Mapping - Security Technical Implementation Guide Version 6.1 APSC-DV-002390 CAT II, APSC-DV-002400 CAT II, APSC-DV-002550 CAT I

[54] Standards Mapping - Security Technical Implementation Guide Version 6.2 APSC-DV-002390 CAT II, APSC-DV-002400 CAT II, APSC-DV-002550 CAT I

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

[56] Standards Mapping - Web Application Security Consortium 24 + 2 Denial of Service

desc.config.xml.weak_xml_schema_unbounded_occurrences