rw-hosts-file: /etc/hosts File Read/Write Check

id: rw-hosts-file

info:
  name: /etc/hosts File Read/Write Check
  author: songyaeji
  severity: high
  description: |
    The /etc/hosts file was writable by non-root users, allowing attackers to register malicious DNS mappings and redirect legitimate domains (pharming attacks). This check verified that /etc/hosts was owned by root and had appropriate permissions.
  reference:
    - https://isms.kisa.or.kr/main/csap/notice/
  metadata:
    verified: true
  tags: local,linux,hosts,file,audit,kisa

self-contained: true

code:
  - engine:
      - sh
      - bash
    source: |
      stat -c "%U %G %a" /etc/hosts 2>/dev/null || echo "not-found"

    matchers:
      - type: regex
        part: response
        regex:
          - '^root\s+root\s+(600|644)$'
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