Access Control: Form Authentication Bypass

C#/VB.NET/ASP.NET

Abstract

アプリケーションは、ネイティブ API への未検証の入力を許可するプロパティを設定し、攻撃者が認証をバイパスできるようにする可能性があります。

Explanation

デフォルトでは、ASP.NET フォーム認証は、認証プロセス中に、ユーザー資格情報を、ネイティブ API に渡す前に検証します。問題は、aspnet:UseLegacyFormsAuthenticationTicketCompatibility 設定を使用してこの機能を変更できる点です。これにより、未検証の入力がネイティブ API に渡され、攻撃者が認証をバイパスできるようになる可能性があります。攻撃者がこの脆弱性の悪用に成功すると、パスワードなしで、既知のユーザー名の ASP.NET フォーム認証をバイパスする可能性があります。続いて攻撃者が、被害者ユーザーのコンテキストで任意のアクション (サイトで任意のコマンドを実行するなど) を実行する可能性があります。

例 1: 次の例では、aspnet:UseLegacyFormsAuthenticationTicketCompatibility が true に設定されています。


...
  <appSettings>
    <add key="aspnet:UseLegacyFormsAuthenticationTicketCompatibility" value="true" />
  </appSettings>
...

References

[1] ASP.NET appSettings Element Microsoft

[2] Microsoft Security Bulletin MS11-100 - Critical Microsoft

[3] Standards Mapping - DISA Control Correlation Identifier Version 2 CCI-000213, CCI-001084, CCI-002165

[4] Standards Mapping - FIPS200 AC

[5] Standards Mapping - General Data Protection Regulation (GDPR) Access Violation

[6] Standards Mapping - NIST Special Publication 800-53 Revision 4 AC-3 Access Enforcement (P1), IA-2 Identification and Authentication (Organizational Users) (P1), IA-11 Re-Authentication (P0), SC-3 Security Function Isolation (P1)

[7] Standards Mapping - NIST Special Publication 800-53 Revision 5 AC-3 Access Enforcement, IA-2 Identification and Authentication (Organizational Users), SC-3 Security Function Isolation, SC-11 Trusted Path

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

[9] Standards Mapping - OWASP Mobile 2014 M5 Poor Authorization and Authentication

[10] Standards Mapping - OWASP Top 10 2004 A3 Broken Authentication and Session Management

[11] Standards Mapping - OWASP Top 10 2007 A7 Broken Authentication and Session Management

[12] Standards Mapping - OWASP Top 10 2010 A3 Broken Authentication and Session Management

[13] Standards Mapping - OWASP Top 10 2013 A2 Broken Authentication and Session Management

[14] Standards Mapping - OWASP Top 10 2017 A2 Broken Authentication

[15] Standards Mapping - OWASP Top 10 2021 A07 Identification and Authentication Failures

[16] Standards Mapping - Payment Card Industry Data Security Standard Version 1.1 Requirement 6.5.2

[17] Standards Mapping - Payment Card Industry Data Security Standard Version 1.2 Requirement 6.5.7

[18] Standards Mapping - Payment Card Industry Data Security Standard Version 2.0 Requirement 6.5.8

[19] Standards Mapping - Payment Card Industry Data Security Standard Version 3.0 Requirement 6.5.8

[20] Standards Mapping - Payment Card Industry Data Security Standard Version 3.1 Requirement 6.5.8

[21] Standards Mapping - Payment Card Industry Data Security Standard Version 3.2 Requirement 6.5.8

[22] Standards Mapping - Payment Card Industry Data Security Standard Version 3.2.1 Requirement 6.5.8

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

[24] Standards Mapping - Payment Card Industry Software Security Framework 1.0 Control Objective 5.4 - Authentication and Access Control

[25] Standards Mapping - Payment Card Industry Software Security Framework 1.1 Control Objective 5.4 - Authentication and Access Control

[26] Standards Mapping - Payment Card Industry Software Security Framework 1.2 Control Objective 5.4 - Authentication and Access Control, Control Objective C.2.3 - Web Software Access Controls

[27] Standards Mapping - SANS Top 25 2011 Porous Defenses - CWE ID 863

[28] Standards Mapping - Security Technical Implementation Guide Version 3.6 APP3610 CAT I

[29] Standards Mapping - Security Technical Implementation Guide Version 3.7 APP3610 CAT I

[30] Standards Mapping - Security Technical Implementation Guide Version 3.9 APP3610 CAT I

[31] Standards Mapping - Security Technical Implementation Guide Version 3.10 APP3610 CAT I

[32] Standards Mapping - Security Technical Implementation Guide Version 4.2 APSC-DV-000460 CAT I, APSC-DV-000470 CAT II, APSC-DV-002360 CAT II

[33] Standards Mapping - Security Technical Implementation Guide Version 4.3 APSC-DV-000460 CAT I, APSC-DV-000470 CAT II, APSC-DV-002360 CAT II

[34] Standards Mapping - Security Technical Implementation Guide Version 4.4 APSC-DV-000460 CAT I, APSC-DV-000470 CAT II, APSC-DV-002360 CAT II

[35] Standards Mapping - Security Technical Implementation Guide Version 4.5 APSC-DV-000460 CAT I, APSC-DV-000470 CAT II, APSC-DV-002360 CAT II

[36] Standards Mapping - Security Technical Implementation Guide Version 4.6 APSC-DV-000460 CAT I, APSC-DV-000470 CAT II, APSC-DV-002360 CAT II

[37] Standards Mapping - Security Technical Implementation Guide Version 4.7 APSC-DV-000460 CAT I, APSC-DV-000470 CAT II, APSC-DV-002360 CAT II

[38] Standards Mapping - Security Technical Implementation Guide Version 4.8 APSC-DV-000460 CAT I, APSC-DV-000470 CAT II, APSC-DV-002360 CAT II

[39] Standards Mapping - Security Technical Implementation Guide Version 4.9 APSC-DV-000460 CAT I, APSC-DV-000470 CAT II, APSC-DV-002360 CAT II

[40] Standards Mapping - Security Technical Implementation Guide Version 4.10 APSC-DV-000460 CAT I, APSC-DV-000470 CAT II, APSC-DV-002360 CAT II

[41] Standards Mapping - Security Technical Implementation Guide Version 4.11 APSC-DV-000460 CAT I, APSC-DV-000470 CAT II, APSC-DV-002360 CAT II

[42] Standards Mapping - Security Technical Implementation Guide Version 4.1 APSC-DV-000460 CAT I, APSC-DV-000470 CAT II, APSC-DV-002360 CAT II

[43] Standards Mapping - Security Technical Implementation Guide Version 5.1 APSC-DV-000460 CAT I, APSC-DV-000470 CAT II, APSC-DV-002360 CAT II

[44] Standards Mapping - Security Technical Implementation Guide Version 5.2 APSC-DV-000460 CAT I, APSC-DV-000470 CAT II, APSC-DV-002360 CAT II

[45] Standards Mapping - Security Technical Implementation Guide Version 5.3 APSC-DV-000460 CAT I, APSC-DV-000470 CAT II, APSC-DV-001520 CAT II, APSC-DV-001530 CAT II, APSC-DV-001540 CAT I, APSC-DV-002360 CAT II

[46] Standards Mapping - Security Technical Implementation Guide Version 6.1 APSC-DV-000460 CAT I, APSC-DV-000470 CAT II, APSC-DV-001520 CAT II, APSC-DV-001530 CAT II, APSC-DV-001540 CAT I, APSC-DV-002360 CAT II

[47] Standards Mapping - Web Application Security Consortium Version 2.00 Insufficient Authentication (WASC-01)

[48] Standards Mapping - Web Application Security Consortium 24 + 2 Insufficient Authentication

desc.configuration.dotnet.access_control_form_authentication_bypass