CVE-2024-9944: WooCommerce HTML Injection Vulnerability

CVE-2024-9944 Overview

The WooCommerce plugin for WordPress contains an HTML Injection vulnerability in all versions up to and including 9.0.2. This security flaw stems from the plugin's failure to properly neutralize HTML elements from submitted order forms. As a result, unauthenticated attackers can inject arbitrary HTML code that renders when administrators view order form submissions, potentially leading to phishing attacks, session hijacking, or other malicious activities targeting store administrators.

Critical Impact

Unauthenticated attackers can inject malicious HTML into order forms that executes in the context of administrator sessions, potentially compromising store management accounts and sensitive customer data.

Affected Products

• WooCommerce plugin for WordPress (free version) up to and including version 9.0.2
• WordPress installations running vulnerable WooCommerce versions
• E-commerce sites using WooCommerce for order processing

Discovery Timeline

• October 15, 2024 - CVE-2024-9944 published to NVD
• October 17, 2024 - Last updated in NVD database

Technical Details for CVE-2024-9944

Vulnerability Analysis

This HTML Injection vulnerability (classified under CWE-79) exists because WooCommerce does not adequately sanitize user-supplied input in order form fields before storing and displaying that data in the administrative interface. When an attacker submits an order containing malicious HTML elements, the unsanitized content is stored in the database and subsequently rendered without proper encoding when an administrator accesses the order details.

The attack requires user interaction, specifically an administrator viewing the compromised order submission. While the vulnerability does not require authentication to exploit initially, its impact is realized when a privileged user interacts with the injected content. The scope is changed, meaning the vulnerable component impacts resources beyond its security scope.

Root Cause

The root cause lies in insufficient input validation and output encoding within the WooCommerce order form processing workflow. The plugin accepts user input from order form fields without properly neutralizing HTML special characters. When this data is later displayed in the WordPress admin panel, the injected HTML is rendered as active markup rather than being displayed as plain text.

Attack Vector

The attack is conducted over the network by submitting specially crafted order forms to vulnerable WooCommerce installations. An attacker does not need any authentication or special privileges to submit a malicious order. The injected HTML payload is stored in the database and triggered when an administrator views the order details in the WordPress admin panel.

The exploitation flow involves:

1. Attacker identifies a WordPress site running a vulnerable WooCommerce version
2. Attacker submits an order form containing malicious HTML in form fields
3. The malicious HTML is stored without sanitization
4. An administrator views the order in the WooCommerce admin interface
5. The injected HTML renders in the administrator's browser context

Detection Methods for CVE-2024-9944

Indicators of Compromise

• Unusual or unexpected HTML tags present in order form submissions
• Order entries containing suspicious script references, iframe elements, or form tags
• Administrator reports of unusual visual content when viewing order details
• Audit logs showing orders with encoded or obfuscated content in text fields

Detection Strategies

• Implement web application firewall (WAF) rules to detect and block HTML injection attempts in form submissions
• Configure server-side logging to capture and flag orders containing HTML markup in customer input fields
• Enable WordPress security plugins that monitor for suspicious order content patterns
• Review WooCommerce order data regularly for anomalous entries containing HTML or JavaScript constructs

Monitoring Recommendations

• Monitor WordPress admin access logs for unusual activity patterns following order reviews
• Set up alerts for orders containing common HTML injection payloads such as <script>, <iframe>, or <form> tags
• Implement content security policies (CSP) to limit the impact of any successful HTML injection
• Track plugin version information and alert when outdated WooCommerce versions are detected

How to Mitigate CVE-2024-9944

Immediate Actions Required

• Update WooCommerce to version 9.1.0 or later immediately
• Review existing orders for potentially malicious HTML content
• Audit administrator accounts for signs of compromise
• Implement additional input validation at the web server or WAF level as a defense-in-depth measure

Patch Information

WooCommerce has addressed this vulnerability in versions released after 9.0.2. The fix involves proper HTML sanitization of order form submissions before storage and display. The patch details can be reviewed in the GitHub Pull Request #49370 and the WordPress Plugin Changeset. Additional vulnerability details are available in the Wordfence Vulnerability Report.

Workarounds

• Implement a Web Application Firewall (WAF) with rules to strip or block HTML tags in form submissions
• Use WordPress security plugins that provide input sanitization for form fields
• Configure server-level input filtering to neutralize HTML special characters in POST requests to WooCommerce endpoints
• Restrict administrative access to trusted IP addresses to reduce the attack surface while awaiting patch deployment

# Example WAF rule for ModSecurity to detect HTML injection attempts
SecRule ARGS "@contains <script" "id:1001,phase:2,deny,status:403,msg:'Potential HTML Injection Attempt'"
SecRule ARGS "@contains <iframe" "id:1002,phase:2,deny,status:403,msg:'Potential HTML Injection Attempt'"
SecRule ARGS "@rx <[a-zA-Z]+" "id:1003,phase:2,log,pass,msg:'HTML Tag Detected in Input'"