# yaml-language-server: $schema=../../../../schema/control.schema.json
id: CB-DEB-AUTH-007
title: Never disable authentication for sudo globally
finding:
  title: sudo is configured to skip authentication
  description: With authentication disabled, every sudo rule works without a password, for every user it applies to.
status: active
profiles: [core]
risk:
  severity: high
assessment: automated
tags: [sudo, privilege-escalation]

applicability:
  facts: [sudo]

description: |
  The `!authenticate` default turns off password checks for every rule it applies to. Unlike a
  `NOPASSWD:` tag on one rule, it is easy to miss because it sits in a `Defaults` line.
rationale: |
  A global `!authenticate` silently turns every administrator account into a password-less root
  account: stealing any of their sessions is enough to control the system.
impact: |
  None for a standard configuration. Debian does not set it.

audit:
  manual: |
    Run `grep -r '!authenticate' /etc/sudoers /etc/sudoers.d/`. There must be no match.
  checks:
    - id: sudoers
      engine: file-content
      description: No !authenticate in /etc/sudoers.
      spec: { path: /etc/sudoers, pattern: "^[^#]*!\\s*authenticate", expect: no_match }
    - id: sudoers-d
      engine: file-content
      description: No !authenticate in /etc/sudoers.d/.
      spec: { path: /etc/sudoers.d/*, pattern: "^[^#]*!\\s*authenticate", expect: no_match }

remediation:
  manual: |
    Remove every `Defaults ... !authenticate` entry with `visudo` (or `visudo -f` for files in
    `/etc/sudoers.d/`).
  rollback: |
    Add the entry back with `visudo`.

references:
  - title: sudoers(5), Debian manual pages
    url: https://manpages.debian.org/trixie/sudo/sudoers.5.en.html
    publisher: Debian
    kind: vendor-doc
    accessed: 2026-10-18
  - title: ANSSI-BP-028 v2.0 - Recommandations de configuration d'un système GNU/Linux (R39)
    url: https://messervices.cyber.gouv.fr/documents-guides/fr_np_linux_configuration-v2.0.pdf
    publisher: ANSSI
    kind: guide
    accessed: 2026-10-18
mappings:
  - framework: anssi-linux
    framework_version: "2.0"
    id: R39
    relation: partial
  - framework: nist-800-53r5
    framework_version: "5.1.1"
    id: IA-11
    relation: related
  - framework: cis-debian-12
    framework_version: "2.0.0"
    id: "5.2.5"
    relation: equivalent
  - framework: cis-debian-13
    framework_version: "1.1.0"
    id: "5.2.5"
    relation: equivalent
threats:
  - framework: mitre-attack
    id: T1548.003

authors:
  - name: Alice
    github: Sn0wAlice
verified:
  - date: 2026-10-18
    by: Sn0wAlice
    versions: ["12"]
    environment: Proxmox VM, Debian 12 genericcloud image, kernel 6.1.0-54-cloud-amd64
    notes: Generated check, fix and check again for profiles core and server-hardened; state kept after reboot.
  - date: 2026-10-18
    by: Sn0wAlice
    versions: ["13"]
    environment: Proxmox VM, Debian 13 genericcloud image, kernel 6.12.113+deb13-cloud-amd64
    notes: Generated check, fix and check again for profiles core and server-hardened; state kept after reboot.
introduced_in: 0.1.0
created: 2026-10-18
updated: 2026-10-18