계: API Abuse

API는 호출자와 피호출자 간의 계약입니다. 가장 흔한 형태의 API 오용은 호출자가 이 계약에서 자신의 몫을 이행하지 못하기 때문에 발생합니다. 예를 들어, 프로그램이 chroot()를 호출한 후 chdir()을 호출하지 못하면 활성 루트 디렉터리를 안전하게 변경하는 방법을 지정하는 계약을 위반하는 것입니다. 라이브러리 오용의 또 다른 좋은 예는 피호출자가 호출자에게 신뢰할 만한 DNS 정보를 반환할 것으로 예상하는 것입니다. 이 경우, 호출자는 자신의 행동에 대해 특정한 가정을 함으로써(반환 값이 인증 목적으로 사용될 것으로 예상) 피호출자 API를 오용합니다. 다른 쪽에서 호출자-피호출자 계약을 위반할 수도 있습니다. 예를 들어, 코더가 하위 클래스 SecureRandom을 지정하고 임의 값이 아닌 값을 반환하는 경우 계약을 위반하는 것입니다.

Kubernetes Misconfiguration: Weak etcd SSL Certificate

YAML

Abstract

etcd 인스턴스가 자체 서명된 인증서를 사용하는 클라이언트의 TLS 연결을 허용합니다.

Explanation

Kubernetes는 민감한 데이터를 etcd 클러스터에 보관합니다. 따라서 모든 etcd 인스턴스는 인증되고 권한 부여된 클라이언트의 연결만 수락하고 자체 서명된 인증서를 TLS 연결에 사용하는 클라이언트를 거부해야 합니다.

예제 1: 다음 구성은 etcd 인스턴스를 시작하고 --auto-tls 플래그를 true로 설정합니다. 결과적으로 etcd 인스턴스는 클라이언트와의 TLS 연결에 자체 서명된 인증서를 사용합니다.


...
spec:
  containers:
  - command:
...
    - etcd
    ...
    - --auto-tls=true
    ...

References

[1] Operating etcd clusters for Kubernetes The Kubernetes Authors

[2] etcd configuration etcd Authors

[3] Standards Mapping - CIS Azure Kubernetes Service Benchmark 2

[4] Standards Mapping - CIS Amazon Elastic Kubernetes Service Benchmark 5

[5] Standards Mapping - CIS Amazon Web Services Foundations Benchmark 1

[6] Standards Mapping - CIS Google Kubernetes Engine Benchmark confidentiality

[7] Standards Mapping - CIS Kubernetes Benchmark complete

[8] Standards Mapping - Common Weakness Enumeration CWE ID 296

[9] Standards Mapping - Common Weakness Enumeration Top 25 2019 [13] CWE ID 287, [25] CWE ID 295

[10] Standards Mapping - Common Weakness Enumeration Top 25 2020 [14] CWE ID 287

[11] Standards Mapping - Common Weakness Enumeration Top 25 2021 [14] CWE ID 287

[12] Standards Mapping - Common Weakness Enumeration Top 25 2022 [14] CWE ID 287

[13] Standards Mapping - DISA Control Correlation Identifier Version 2 CCI-000185, CCI-001941, CCI-001942

[14] Standards Mapping - FIPS200 CM

[15] Standards Mapping - General Data Protection Regulation (GDPR) Insufficient Data Protection

[16] Standards Mapping - NIST Special Publication 800-53 Revision 4 SC-17 Public Key Infrastructure Certificates (P1)

[17] Standards Mapping - NIST Special Publication 800-53 Revision 5 SC-17 Public Key Infrastructure Certificates

[18] Standards Mapping - OWASP Top 10 2004 A10 Insecure Configuration Management

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

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

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

[22] Standards Mapping - OWASP Top 10 2021 A02 Cryptographic Failures

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

[24] Standards Mapping - OWASP Application Security Verification Standard 4.0 2.6.3 Look-up Secret Verifier Requirements (L2 L3), 2.7.1 Out of Band Verifier Requirements (L1 L2 L3), 2.7.2 Out of Band Verifier Requirements (L1 L2 L3), 2.7.3 Out of Band Verifier Requirements (L1 L2 L3), 2.8.4 Single or Multi Factor One Time Verifier Requirements (L2 L3), 2.8.5 Single or Multi Factor One Time Verifier Requirements (L2 L3), 3.7.1 Defenses Against Session Management Exploits (L1 L2 L3), 6.2.1 Algorithms (L1 L2 L3), 9.2.1 Server Communications Security Requirements (L2 L3), 9.2.3 Server Communications Security Requirements (L2 L3)

[25] Standards Mapping - OWASP Mobile 2014 M3 Insufficient Transport Layer Protection

[26] Standards Mapping - Payment Card Industry Data Security Standard Version 1.1 Requirement 6.5.10

[27] Standards Mapping - Payment Card Industry Data Security Standard Version 1.2 Requirement 6.5.9

[28] Standards Mapping - Payment Card Industry Data Security Standard Version 2.0 Requirement 6.5.4

[29] Standards Mapping - Payment Card Industry Data Security Standard Version 3.0 Requirement 6.5.4

[30] Standards Mapping - Payment Card Industry Data Security Standard Version 3.2 Requirement 6.5.4

[31] Standards Mapping - Payment Card Industry Data Security Standard Version 3.2.1 Requirement 6.5.4

[32] Standards Mapping - Payment Card Industry Data Security Standard Version 3.1 Requirement 6.5.4

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

[34] Standards Mapping - Payment Card Industry Software Security Framework 1.0 Control Objective 7.1 - Use of Cryptography

[35] Standards Mapping - Payment Card Industry Software Security Framework 1.1 Control Objective 7.1 - Use of Cryptography, Control Objective B.2.3 - Terminal Software Design

[36] Standards Mapping - Payment Card Industry Software Security Framework 1.2 Control Objective 7.1 - Use of Cryptography, Control Objective B.2.3 - Terminal Software Design

[37] Standards Mapping - Security Technical Implementation Guide Version 3.1 APP3305 CAT I

[38] Standards Mapping - Security Technical Implementation Guide Version 3.4 APP3305 CAT I

[39] Standards Mapping - Security Technical Implementation Guide Version 3.5 APP3305 CAT I

[40] Standards Mapping - Security Technical Implementation Guide Version 3.6 APP3305 CAT I

[41] Standards Mapping - Security Technical Implementation Guide Version 3.7 APP3305 CAT I

[42] Standards Mapping - Security Technical Implementation Guide Version 3.9 APP3305 CAT I

[43] Standards Mapping - Security Technical Implementation Guide Version 3.10 APP3305 CAT I

[44] Standards Mapping - Security Technical Implementation Guide Version 4.1 APSC-DV-001620 CAT II, APSC-DV-001630 CAT II, APSC-DV-001810 CAT I

[45] Standards Mapping - Security Technical Implementation Guide Version 4.2 APSC-DV-001620 CAT II, APSC-DV-001630 CAT II, APSC-DV-001810 CAT I

[46] Standards Mapping - Security Technical Implementation Guide Version 4.3 APSC-DV-001620 CAT II, APSC-DV-001630 CAT II, APSC-DV-001810 CAT I

[47] Standards Mapping - Security Technical Implementation Guide Version 4.4 APSC-DV-001620 CAT II, APSC-DV-001630 CAT II, APSC-DV-001810 CAT I

[48] Standards Mapping - Security Technical Implementation Guide Version 4.5 APSC-DV-001620 CAT II, APSC-DV-001630 CAT II, APSC-DV-001810 CAT I

[49] Standards Mapping - Security Technical Implementation Guide Version 4.6 APSC-DV-001620 CAT II, APSC-DV-001630 CAT II, APSC-DV-001810 CAT I

[50] Standards Mapping - Security Technical Implementation Guide Version 4.7 APSC-DV-001620 CAT II, APSC-DV-001630 CAT II, APSC-DV-001810 CAT I

[51] Standards Mapping - Security Technical Implementation Guide Version 4.8 APSC-DV-001620 CAT II, APSC-DV-001630 CAT II, APSC-DV-001810 CAT I

[52] Standards Mapping - Security Technical Implementation Guide Version 4.9 APSC-DV-001620 CAT II, APSC-DV-001630 CAT II, APSC-DV-001810 CAT I

[53] Standards Mapping - Security Technical Implementation Guide Version 4.10 APSC-DV-001620 CAT II, APSC-DV-001630 CAT II, APSC-DV-001810 CAT I

[54] Standards Mapping - Security Technical Implementation Guide Version 4.11 APSC-DV-001620 CAT II, APSC-DV-001630 CAT II, APSC-DV-001810 CAT I

[55] Standards Mapping - Security Technical Implementation Guide Version 5.1 APSC-DV-001620 CAT II, APSC-DV-001630 CAT II, APSC-DV-001810 CAT I

[56] Standards Mapping - Security Technical Implementation Guide Version 5.2 APSC-DV-001620 CAT II, APSC-DV-001630 CAT II, APSC-DV-001810 CAT I

[57] Standards Mapping - Security Technical Implementation Guide Version 5.3 APSC-DV-000590 CAT II

[58] Standards Mapping - Web Application Security Consortium Version 2.00 Application Misconfiguration (WASC-15), Insufficient Authentication (WASC-01)

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

desc.structural.yaml.kubernetes_misconfiguration_weak_etcd_ssl_certificate.base