Ensure service-account-key-file set

ID: k8s-svc-acct-key

Severity: medium

Author: princechaddha

Tags: cloud,devops,kubernetes,security,devsecops,api-server,k8s,k8s-cluster-security

Description

Checks if the service-account-key-file argument is properly set in the API server configuration, which is critical for validating service account tokens.

YAML Source

id: k8s-svc-acct-key

info:
  name: Ensure service-account-key-file set
  author: princechaddha
  severity: medium
  description: Checks if the service-account-key-file argument is properly set in the API server configuration, which is critical for validating service account tokens.
  impact: |
    The absence of the service-account-key-file argument means that the API server might not perform robust authentication checks for service accounts, potentially allowing unauthorized access.
  remediation: |
    Configure the API server to use a service-account-key-file that points to a valid private key used to sign service account tokens. This setting should be part of the API server startup arguments or in its configuration file.
  reference:
    - https://kubernetes.io/docs/admin/kube-apiserver/
  tags: cloud,devops,kubernetes,security,devsecops,api-server,k8s,k8s-cluster-security

variables:
  argument: "service-account-key-file"

self-contained: true
code:
  - engine:
      - sh
      - bash
    source: |
      kubectl get pods -n kube-system -l component=kube-apiserver -o jsonpath="{.items[*].spec.containers[*].command}"

    matchers-condition: and
    matchers:
      - type: word
        words:
          - 'kube-apiserver'

      - type: word
        words:
          - "service-account-key-file"
        negative: true

    extractors:
      - type: dsl
        dsl:
          - '"API server configuration is missing the " + argument + " argument."'
# digest: 490a0046304402205ad5cf2ea51311668b71b3ba9acff690115a3f9b15e997406d41351a3244d7fe022019182b0be129f25cea061265dfca2908064de2c5b0c7bcb7dae19411250573c7:922c64590222798bb761d5b6d8e72950

Guide to check the vulnerabilities

This template is used to detect vulnerabilities in web applications. It can be used with the Nuclei tool to scan for specific patterns or behaviors.

$ nuclei -u "URL" -t "cloud/kubernetes/security-compliance/k8s-svc-acct-key.yaml"

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