界: API Abuse

API は、呼び出し元と呼び出し先の間のコントラクトです。最も一般的な API の不正使用の形態は、呼び出し元がこのコントラクトの終わりを守らないことによって発生します。たとえば、プログラムが chroot() を呼び出した後に chdir() を呼び出すのに失敗すると、アクティブなルート ディレクトリを安全に変更する方法を指定したコントラクトに違反することになります。ライブラリの悪用のもう 1 つの良い例は、呼び出し先が信頼できる DNS 情報を呼び出し元に返すことを期待することです。この場合、呼び出し元は、呼び出し先の API の動作 (戻り値が認証目的に使用できること) についてある種の仮定をすることで、呼び出し先の API を悪用します。また、相手側から、呼び出し元と呼び出し先のコントラクトを違反することもできます。例えば、コーダーが SecureRandom をサブクラス化し、ランダムではない値を返した場合、コントラクトに違反することになります。

Struts 2 Bad Practices: Dynamic Method Invocation

Abstract
Struts 2 アクションは、アクションの execute() メソッドを上書きするエンドユーザーによって呼び出すことのできる public メソッドを開示します。
Explanation
Struts 2 には「Dynamic Method Invocation」という機能があり、これにより Action によって execute() 以外のメソッドを開示できます。! (感嘆符) 文字または method: プレフィックスを Action URL に使用して、「Dynamic Method Invocation」が有効に設定されていれば Action でどの public メソッドでも呼び出すことができます。この機能を知らない開発者は、内部のビジネスロジックを攻撃者に対して無防備に開示してしまう可能性があります。

たとえば、Action に getUserPassword() という public メソッドが含まれており、何の引数もともなわず「Dynamic Method Invocation」機能を無効にできない場合、攻撃者はこれに目を付けて以下の URL を閲覧できます。 http://server/app/recoverpassword!getPassword.action
References
[1] Struts 2 Security Vulnerability - Dynamic Method Invocation
[2] Struts 2 - Dynamic Method Invocation
[3] Standards Mapping - Common Weakness Enumeration CWE ID 285
[4] Standards Mapping - DISA Control Correlation Identifier Version 2 CCI-000213, CCI-001764, CCI-001774, CCI-002165
[5] Standards Mapping - FIPS200 AC
[6] Standards Mapping - General Data Protection Regulation (GDPR) Indirect Access to Sensitive Data
[7] Standards Mapping - NIST Special Publication 800-53 Revision 4 AC-3 Access Enforcement (P1), CM-7 Least Functionality (P1)
[8] Standards Mapping - NIST Special Publication 800-53 Revision 5 AC-3 Access Enforcement, CM-7 Least Functionality
[9] Standards Mapping - OWASP API 2023 API5 Broken Function Level Authorization
[10] Standards Mapping - OWASP Application Security Verification Standard 4.0 4.1.3 General Access Control Design (L1 L2 L3), 4.1.5 General Access Control Design (L1 L2 L3), 4.2.1 Operation Level Access Control (L1 L2 L3), 13.1.4 Generic Web Service Security Verification Requirements (L2 L3)
[11] Standards Mapping - OWASP Mobile 2014 M1 Weak Server Side Controls
[12] Standards Mapping - OWASP Top 10 2004 A2 Broken Access Control
[13] Standards Mapping - OWASP Top 10 2007 A4 Insecure Direct Object Reference
[14] Standards Mapping - OWASP Top 10 2010 A4 Insecure Direct Object References
[15] Standards Mapping - OWASP Top 10 2013 A4 Insecure Direct Object References
[16] Standards Mapping - OWASP Top 10 2017 A5 Broken Access Control
[17] Standards Mapping - OWASP Top 10 2021 A01 Broken Access Control
[18] Standards Mapping - Payment Card Industry Data Security Standard Version 1.1 Requirement 6.5.2
[19] Standards Mapping - Payment Card Industry Data Security Standard Version 1.2 Requirement 6.5.4
[20] Standards Mapping - Payment Card Industry Data Security Standard Version 2.0 Requirement 6.5.8
[21] Standards Mapping - Payment Card Industry Data Security Standard Version 3.0 Requirement 6.5.8
[22] Standards Mapping - Payment Card Industry Data Security Standard Version 3.1 Requirement 6.5.8
[23] Standards Mapping - Payment Card Industry Data Security Standard Version 3.2 Requirement 6.5.8
[24] Standards Mapping - Payment Card Industry Data Security Standard Version 3.2.1 Requirement 6.5.8
[25] Standards Mapping - Payment Card Industry Data Security Standard Version 4.0 Requirement 6.2.4
[26] Standards Mapping - Payment Card Industry Data Security Standard Version 4.0.1 Requirement 6.2.4
[27] Standards Mapping - Payment Card Industry Software Security Framework 1.0 Control Objective 5.4 - Authentication and Access Control
[28] Standards Mapping - Payment Card Industry Software Security Framework 1.1 Control Objective 5.4 - Authentication and Access Control
[29] 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
[30] Standards Mapping - SANS Top 25 2009 Porous Defenses - CWE ID 285
[31] Standards Mapping - SANS Top 25 2010 Porous Defenses - CWE ID 285
[32] Standards Mapping - SANS Top 25 2011 Porous Defenses - CWE ID 862
[33] Standards Mapping - Security Technical Implementation Guide Version 3.1 APP3510 CAT I
[34] Standards Mapping - Security Technical Implementation Guide Version 3.4 APP3510 CAT I
[35] Standards Mapping - Security Technical Implementation Guide Version 3.5 APP3510 CAT I
[36] Standards Mapping - Security Technical Implementation Guide Version 3.6 APP3510 CAT I
[37] Standards Mapping - Security Technical Implementation Guide Version 3.7 APP3510 CAT I
[38] Standards Mapping - Security Technical Implementation Guide Version 3.9 APP3510 CAT I
[39] Standards Mapping - Security Technical Implementation Guide Version 3.10 APP3510 CAT I
[40] Standards Mapping - Security Technical Implementation Guide Version 4.2 APSC-DV-000460 CAT I, APSC-DV-000470 CAT II, APSC-DV-001480 CAT II, APSC-DV-001490 CAT II
[41] Standards Mapping - Security Technical Implementation Guide Version 4.3 APSC-DV-000460 CAT I, APSC-DV-000470 CAT II, APSC-DV-001480 CAT II, APSC-DV-001490 CAT II
[42] Standards Mapping - Security Technical Implementation Guide Version 4.4 APSC-DV-000460 CAT I, APSC-DV-000470 CAT II, APSC-DV-001480 CAT II, APSC-DV-001490 CAT II
[43] Standards Mapping - Security Technical Implementation Guide Version 4.5 APSC-DV-000460 CAT I, APSC-DV-000470 CAT II, APSC-DV-001480 CAT II, APSC-DV-001490 CAT II
[44] Standards Mapping - Security Technical Implementation Guide Version 4.6 APSC-DV-000460 CAT I, APSC-DV-000470 CAT II, APSC-DV-001480 CAT II, APSC-DV-001490 CAT II
[45] Standards Mapping - Security Technical Implementation Guide Version 4.7 APSC-DV-000460 CAT I, APSC-DV-000470 CAT II, APSC-DV-001480 CAT II, APSC-DV-001490 CAT II
[46] Standards Mapping - Security Technical Implementation Guide Version 4.8 APSC-DV-000460 CAT I, APSC-DV-000470 CAT II, APSC-DV-001480 CAT II, APSC-DV-001490 CAT II
[47] Standards Mapping - Security Technical Implementation Guide Version 4.9 APSC-DV-000460 CAT I, APSC-DV-000470 CAT II, APSC-DV-001480 CAT II, APSC-DV-001490 CAT II
[48] Standards Mapping - Security Technical Implementation Guide Version 4.10 APSC-DV-000460 CAT I, APSC-DV-000470 CAT II, APSC-DV-001480 CAT II, APSC-DV-001490 CAT II
[49] Standards Mapping - Security Technical Implementation Guide Version 4.11 APSC-DV-000460 CAT I, APSC-DV-000470 CAT II, APSC-DV-001480 CAT II, APSC-DV-001490 CAT II
[50] Standards Mapping - Security Technical Implementation Guide Version 4.1 APSC-DV-000460 CAT I, APSC-DV-000470 CAT II, APSC-DV-001480 CAT II, APSC-DV-001490 CAT II
[51] Standards Mapping - Security Technical Implementation Guide Version 5.1 APSC-DV-000460 CAT I, APSC-DV-000470 CAT II, APSC-DV-001480 CAT II, APSC-DV-001490 CAT II
[52] Standards Mapping - Security Technical Implementation Guide Version 5.2 APSC-DV-000460 CAT I, APSC-DV-000470 CAT II, APSC-DV-001480 CAT II, APSC-DV-001490 CAT II
[53] Standards Mapping - Security Technical Implementation Guide Version 5.3 APSC-DV-000460 CAT I, APSC-DV-000470 CAT II, APSC-DV-001480 CAT II, APSC-DV-001490 CAT II
[54] Standards Mapping - Security Technical Implementation Guide Version 6.1 APSC-DV-000460 CAT I, APSC-DV-000470 CAT II, APSC-DV-001480 CAT II, APSC-DV-001490 CAT II
[55] Standards Mapping - Web Application Security Consortium Version 2.00 Insufficient Authorization (WASC-02)
[56] Standards Mapping - Web Application Security Consortium 24 + 2 Insufficient Authorization
desc.structural.java.struts2_bad_practices_dynamic_method_invocation