# yaml-language-server: $schema=../../../../schema/control.schema.json
id: CB-DEB-AUTH-006
title: Require a password for every sudo rule
finding:
  title: Some sudo rules run commands without asking for a password
  description: Anyone who takes over such an account, or just an unlocked session, gets root without knowing any secret.
status: active
profiles: [server-hardened, desktop-hardened]
risk:
  severity: high
assessment: automated
tags: [sudo, privilege-escalation]

applicability:
  facts: [sudo]

description: |
  A sudo rule tagged `NOPASSWD:` runs commands without asking the user for their password.
rationale: |
  The password prompt is the last barrier between a stolen session or a compromised process
  running as an administrator and full control of the system. Without it, privilege escalation
  needs no secret at all.
impact: |
  Automation that relies on password-less sudo (configuration management, deployment accounts)
  needs another approach: a dedicated account restricted to precise commands, run from a
  controlled host, or root access through SSH keys for that tool only.
notes: |
  Debian cloud images get a `NOPASSWD:ALL` rule for the default user from cloud-init, in
  `/etc/sudoers.d/90-cloud-init-users`. Set a password for that user before removing the rule.

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

remediation:
  manual: |
    1. Make sure every user concerned has a password (`passwd <user>`) and can still run `sudo -v`.
    2. Edit the files with `visudo` (or `visudo -f /etc/sudoers.d/<file>`) and remove `NOPASSWD:`
       from each rule.
  rollback: |
    Add the `NOPASSWD:` tag 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: "5.2.4"
    relation: equivalent
  - framework: cis-debian-13
    framework_version: "1.1.0"
    id: "5.2.4"
    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: Fails on the cloud image (cloud-init NOPASSWD rule) as expected; manual fix.
  - date: 2026-10-18
    by: Sn0wAlice
    versions: ["13"]
    environment: Proxmox VM, Debian 13 genericcloud image, kernel 6.12.113+deb13-cloud-amd64
    notes: Fails on the cloud image (cloud-init NOPASSWD rule) as expected; manual fix.
introduced_in: 0.1.0
created: 2026-10-18
updated: 2026-10-18