CVE-2024-39650: WooCommerce PDF Vouchers Auth Bypass Flaw

CVE-2024-39650 Overview

CVE-2024-39650 is a Missing Authorization vulnerability affecting the WooCommerce PDF Vouchers plugin developed by WPWeb Elite for WordPress. This security flaw allows unauthenticated attackers to access functionality that is not properly constrained by Access Control Lists (ACLs), potentially leading to unauthorized access to sensitive voucher data and plugin functionality.

Critical Impact

Unauthenticated attackers can bypass authorization controls to access restricted plugin functionality, potentially compromising voucher systems, customer data, and store operations without requiring any authentication.

Affected Products

• WPWeb Elite WooCommerce PDF Vouchers versions up to and including 4.9.4
• WordPress installations running affected versions of the plugin
• WooCommerce stores utilizing the PDF Vouchers functionality

Discovery Timeline

• 2024-11-01 - CVE-2024-39650 published to NVD
• 2026-01-26 - Last updated in NVD database

Technical Details for CVE-2024-39650

Vulnerability Analysis

This vulnerability falls under CWE-862 (Missing Authorization), which occurs when the software does not perform an authorization check when an actor attempts to access a resource or perform an action. In the context of the WooCommerce PDF Vouchers plugin, certain functionality lacks proper authorization checks, allowing unauthenticated users to access features that should be restricted to authenticated administrators or privileged users.

The vulnerability enables attackers to bypass normal access control mechanisms and interact with plugin functionality as if they had legitimate permissions. This can result in unauthorized data access, manipulation of voucher systems, and potential compromise of sensitive customer information stored within the WooCommerce ecosystem.

Root Cause

The root cause of CVE-2024-39650 stems from inadequate implementation of authorization checks within the WooCommerce PDF Vouchers plugin. The affected codebase fails to verify whether the requesting user has appropriate permissions before granting access to protected functionality. This missing authorization validation allows any unauthenticated remote user to invoke restricted features that should only be accessible to authorized administrators or specific user roles.

The vulnerability specifically relates to improper Access Control List (ACL) constraints, where the plugin does not properly enforce permission boundaries between public and administrative functionality.

Attack Vector

The attack vector for this vulnerability is network-based and requires no authentication or user interaction. An attacker can remotely exploit this vulnerability by sending specially crafted requests to the vulnerable WordPress installation running the affected plugin version.

The vulnerability allows attackers to access functionality not properly constrained by ACLs. This includes the ability to potentially view, modify, or delete voucher data, access customer information associated with vouchers, and manipulate plugin settings that should be restricted to administrators.

Since no authentication is required and the attack complexity is low, this vulnerability presents a significant risk to any WordPress site running the affected plugin versions. Further technical details can be found in the Patchstack vulnerability database.

Detection Methods for CVE-2024-39650

Indicators of Compromise

• Unexpected access to voucher-related API endpoints from unauthenticated sources
• Unusual patterns in WordPress access logs showing requests to PDF voucher plugin endpoints without valid session cookies
• Modifications to voucher data or plugin settings without corresponding authenticated admin activity
• Suspicious GET or POST requests targeting WooCommerce PDF Vouchers plugin directories

Detection Strategies

• Implement web application firewall (WAF) rules to monitor and alert on suspicious requests to the WooCommerce PDF Vouchers plugin endpoints
• Review WordPress access logs for unauthenticated requests attempting to access administrative plugin functionality
• Deploy file integrity monitoring to detect unauthorized changes to voucher-related data or plugin configurations
• Utilize WordPress security plugins that can detect and alert on authorization bypass attempts

Monitoring Recommendations

• Enable detailed logging for all WooCommerce PDF Vouchers plugin activity
• Configure alerts for any access to voucher management functions from non-authenticated sessions
• Monitor for bulk or automated requests targeting plugin endpoints that indicate exploitation attempts
• Regularly audit user activity logs for anomalous voucher operations

How to Mitigate CVE-2024-39650

Immediate Actions Required

• Update WooCommerce PDF Vouchers plugin to a version newer than 4.9.4 immediately
• Review access logs for evidence of exploitation prior to patching
• Audit all voucher data and plugin configurations for unauthorized modifications
• Consider temporarily disabling the plugin if an immediate update is not possible

Patch Information

Organizations using WooCommerce PDF Vouchers should update to the latest available version that addresses this authorization bypass vulnerability. The vulnerability affects all versions from the initial release through version 4.9.4. Check the WordPress plugin repository or the official WPWeb Elite website for the latest patched version.

Before updating, ensure you have a complete backup of your WordPress installation, including the database and all plugin files. Test the update in a staging environment if possible before deploying to production.

Workarounds

• Implement additional authorization controls at the web server level using .htaccess rules or nginx configuration to restrict access to plugin endpoints
• Deploy a Web Application Firewall (WAF) with rules to block unauthenticated access to vulnerable plugin functionality
• Temporarily restrict access to the WordPress admin area and plugin endpoints to trusted IP addresses only
• Consider disabling the WooCommerce PDF Vouchers plugin entirely until a patched version can be deployed

# Example .htaccess restriction for WordPress plugin directory
<IfModule mod_rewrite.c>
RewriteEngine On
RewriteCond %{REQUEST_URI} ^/wp-content/plugins/woocommerce-pdf-vouchers/
RewriteCond %{HTTP_COOKIE} !wordpress_logged_in
RewriteRule ^(.*)$ - [F,L]
</IfModule>