CVE-2025-2563: User Registration Privilege Escalation

CVE-2025-2563 Overview

CVE-2025-2563 is a privilege escalation vulnerability affecting the User Registration & Membership WordPress plugin developed by WPEverest. The vulnerability exists in versions prior to 4.1.2 and allows unauthenticated users to set their account role when the Membership Addon is enabled, potentially enabling attackers to gain administrative privileges on affected WordPress installations.

Critical Impact

Unauthenticated attackers can escalate privileges to administrator level, leading to complete WordPress site compromise including data theft, malware injection, and website defacement.

Affected Products

• WPEverest User Registration & Membership (Free) versions before 4.1.2
• WPEverest User Registration & Membership (Pro) versions before 4.1.2
• WordPress sites with Membership Addon enabled

Discovery Timeline

• April 14, 2025 - CVE-2025-2563 published to NVD
• April 29, 2025 - Last updated in NVD database

Technical Details for CVE-2025-2563

Vulnerability Analysis

This privilege escalation vulnerability stems from improper access control within the User Registration & Membership plugin when the Membership Addon feature is enabled. The plugin fails to properly validate and restrict the user role parameter during the registration process, allowing attackers to manipulate their assigned role.

When a new user registers through the affected plugin with the Membership Addon active, the application does not adequately verify whether the requesting user has authorization to specify certain account roles. This oversight allows unauthenticated users to craft requests that assign themselves elevated privileges, including administrator-level access.

The attack can be executed remotely over the network without requiring any prior authentication. Once an attacker successfully escalates to an administrator role, they gain complete control over the WordPress installation, including the ability to modify content, install malicious plugins, access sensitive user data, and potentially pivot to the underlying server infrastructure.

Root Cause

The root cause of this vulnerability is insufficient authorization checks in the user registration workflow when the Membership Addon is enabled. The plugin does not properly restrict which roles can be assigned during account creation, allowing users to bypass intended role restrictions. This represents a classic broken access control vulnerability where the application fails to enforce role-based permissions during a critical user provisioning operation.

Attack Vector

The attack is conducted remotely via the network and targets the WordPress registration functionality. An attacker can exploit this vulnerability by:

1. Identifying a WordPress site running a vulnerable version of the User Registration & Membership plugin with the Membership Addon enabled
2. Initiating a user registration request through the plugin's registration form or API
3. Manipulating the role parameter in the registration request to specify an administrator or other privileged role
4. Successfully creating an account with elevated privileges without requiring any prior authentication

The vulnerability allows unauthenticated exploitation, meaning attackers do not need any existing credentials or session to carry out the attack. For detailed technical information about this vulnerability, refer to the WPScan vulnerability advisory.

Detection Methods for CVE-2025-2563

Indicators of Compromise

• Unexpected administrator or privileged user accounts appearing in WordPress user lists
• New user registrations with administrator-level roles that were not created by legitimate site administrators
• Suspicious activity in WordPress audit logs related to user registration events
• Unauthorized changes to site settings, themes, or plugins following new user registrations

Detection Strategies

• Monitor WordPress user creation events for accounts being assigned privileged roles during registration
• Implement web application firewall (WAF) rules to detect manipulation of role parameters in registration requests
• Review server access logs for unusual registration traffic patterns or bulk registration attempts
• Deploy endpoint detection solutions like SentinelOne to identify post-exploitation activity following privilege escalation

Monitoring Recommendations

• Enable comprehensive logging for all WordPress user management operations
• Configure alerts for new administrator account creation events
• Periodically audit the WordPress user database for unauthorized privileged accounts
• Monitor for indicators of WordPress compromise including modified core files, suspicious plugins, or webshells

How to Mitigate CVE-2025-2563

Immediate Actions Required

• Update the User Registration & Membership plugin to version 4.1.2 or later immediately
• Audit existing WordPress user accounts for any unauthorized administrator or privileged accounts
• Review site activity logs for signs of exploitation or unauthorized access
• Consider temporarily disabling the Membership Addon until the update can be applied
• Reset passwords for all administrator accounts as a precautionary measure

Patch Information

WPEverest has addressed this vulnerability in User Registration & Membership plugin version 4.1.2. Site administrators should update to this version or later through the WordPress plugin management interface or by manually downloading the updated plugin from the official WordPress plugin repository. For additional details, consult the WPScan vulnerability advisory.

Workarounds

• Temporarily disable the Membership Addon feature until the patch can be applied
• Implement strict WAF rules to block or monitor registration requests with suspicious role parameters
• Use WordPress security plugins to restrict registration capabilities or add additional verification steps
• Consider disabling user registration entirely if not critical to site operations until the update is deployed

# Configuration example - Disable user registration via wp-config.php
# Add the following line to your wp-config.php file to disable public registration
define('WP_ALLOW_REGISTRATION', false);

# Alternatively, verify plugin version via WP-CLI
wp plugin list --fields=name,version | grep user-registration