CVE-2024-50503: User Toolkit Auth Bypass Vulnerability

CVE-2024-50503 Overview

CVE-2024-50503 is an authentication bypass vulnerability in the Deryck User Toolkit plugin for WordPress. The flaw affects all versions up to and including 1.2.3. An unauthenticated remote attacker can bypass authentication using an alternate path or channel, leading to account takeover.

The vulnerability is classified under CWE-288: Authentication Bypass Using an Alternate Path or Channel. Successful exploitation compromises confidentiality, integrity, and availability of affected WordPress sites without requiring user interaction or prior privileges.

Critical Impact

Unauthenticated attackers can take over arbitrary user accounts, including administrators, on WordPress sites running the User Toolkit plugin version 1.2.3 or earlier.

Affected Products

• Deryck User Toolkit plugin for WordPress
• All versions from initial release through 1.2.3
• WordPress sites with the plugin installed and activated

Discovery Timeline

• 2024-10-30 - CVE-2024-50503 published to NVD
• 2026-04-23 - Last updated in NVD database

Technical Details for CVE-2024-50503

Vulnerability Analysis

The User Toolkit plugin exposes an authentication routine that fails to enforce identity verification through its primary access controls. Attackers can reach an alternate authentication path that does not validate the requesting user's credentials or capabilities. This path accepts user identifiers and returns authenticated sessions for the specified account.

The vulnerability enables account takeover against any user registered on the target WordPress site. Attackers targeting administrator accounts gain full control of the site, including content modification, plugin installation, and database access. The flaw requires no authentication, no user interaction, and is exploitable over the network.

Root Cause

The root cause is improper enforcement of authentication on a secondary code path within the plugin. The plugin's user-switching or impersonation functionality does not validate that the caller possesses the required capability, such as manage_options or an equivalent privilege check. The alternate channel trusts client-supplied identity parameters without verification.

This pattern aligns with CWE-288, where a product has an authentication mechanism but a secondary path bypasses it. The plugin exposes functionality intended for administrators to all visitors.

Attack Vector

The attack vector is network-based and remote. An attacker sends a crafted HTTP request to the WordPress site targeting the vulnerable endpoint exposed by the User Toolkit plugin. The request specifies the target user account, and the plugin issues a valid authenticated session for that account.

No credentials, tokens, or user interaction are required. Refer to the Patchstack advisory for additional context on the affected endpoint and parameters.

Detection Methods for CVE-2024-50503

Indicators of Compromise

• Unexpected administrator logins from unfamiliar IP addresses in WordPress audit logs
• New administrator accounts or role changes not initiated by legitimate users
• HTTP requests to User Toolkit plugin endpoints originating from external IPs without prior authentication cookies
• Modification of WordPress core files, themes, or plugins following plugin endpoint access

Detection Strategies

• Inventory WordPress installations and confirm whether the User Toolkit plugin is installed and at which version
• Review web server access logs for requests to /wp-content/plugins/user-toolkit/ endpoints from unauthenticated sessions
• Correlate plugin endpoint requests with subsequent authenticated administrator activity from the same IP
• Deploy WordPress security plugins or web application firewall rules that flag known account-takeover patterns

Monitoring Recommendations

• Forward WordPress authentication events and plugin activity to a centralized log platform for retention and analysis
• Alert on creation of new administrator accounts or elevation of existing user roles
• Monitor outbound connections from the web server for signs of post-exploitation activity such as webshell installation
• Track plugin file integrity to identify tampering after a suspected takeover

How to Mitigate CVE-2024-50503

Immediate Actions Required

• Update the Deryck User Toolkit plugin to a version above 1.2.3 as soon as a patched release is published
• Deactivate and remove the plugin if no patched version is available and the functionality is non-essential
• Force password resets and invalidate active sessions for all WordPress users, prioritizing administrators
• Audit user accounts and roles to identify unauthorized additions or privilege changes

Patch Information

At the time of CVE publication, the vulnerability affected User Toolkit versions through 1.2.3. Site administrators should consult the Patchstack advisory for the latest fixed version and apply the update through the WordPress plugin manager.

Workarounds

• Block external access to the plugin's endpoints using web application firewall rules until a patch is applied
• Restrict WordPress administrative URLs by source IP address through web server configuration
• Enable multi-factor authentication on all administrator accounts to limit damage from session theft
• Place the WordPress site behind a reverse proxy that enforces authentication before requests reach the plugin

# Example nginx rule to block requests to the vulnerable plugin path
location ~* /wp-content/plugins/user-toolkit/ {
    deny all;
    return 403;
}