CVE-2025-3844: WordPress Plugin Auth Bypass Vulnerability

CVE-2025-3844 Overview

The PeproDev Ultimate Profile Solutions plugin for WordPress contains a critical Authentication Bypass vulnerability affecting versions 1.9.1 through 7.5.2. The vulnerability exists in the handel_ajax_req() function, which lacks proper restrictions on the change_user_meta functionality. This flaw allows attackers to arbitrarily set a One-Time Password (OTP) code and subsequently authenticate using that OTP, effectively bypassing the normal authentication process entirely.

Critical Impact

Unauthenticated attackers can bypass authentication and log in as any user on the site, including administrators, leading to complete site compromise.

Affected Products

• PeproDev Ultimate Profile Solutions WordPress Plugin versions 1.9.1 to 7.5.2

Discovery Timeline

• 2025-05-07 - CVE-2025-3844 published to NVD
• 2025-05-07 - Last updated in NVD database

Technical Details for CVE-2025-3844

Vulnerability Analysis

This Authentication Bypass vulnerability (CWE-288) allows unauthenticated remote attackers to completely circumvent the WordPress authentication mechanism. The vulnerability resides in the plugin's AJAX request handler, specifically the handel_ajax_req() function located in the login.php file.

The core issue is that the function does not adequately validate or restrict access to the change_user_meta functionality. This allows an attacker to manipulate user metadata, specifically to inject or modify OTP codes associated with any user account. Once an attacker sets a known OTP value for a target user (including administrator accounts), they can use that OTP to authenticate as that user without knowing the actual password.

The attack is particularly dangerous because it requires no prior authentication, making it exploitable by any remote attacker with network access to the vulnerable WordPress installation.

Root Cause

The root cause of this vulnerability is insufficient access control in the handel_ajax_req() function. The function fails to verify that the requesting user has appropriate privileges before allowing modifications to user metadata through the change_user_meta functionality. This missing authorization check enables unauthenticated users to perform privileged operations that should be restricted to authenticated administrators.

Attack Vector

The attack can be executed remotely over the network without any authentication. An attacker would:

1. Send a crafted AJAX request to the WordPress site targeting the vulnerable handel_ajax_req() endpoint
2. Manipulate the change_user_meta functionality to set a known OTP value for a target user account
3. Use the injected OTP value to authenticate through the plugin's OTP-based login mechanism
4. Gain full access to the target account, including administrator accounts

The vulnerability in the AJAX handler can be examined at the WordPress Plugin Trac repository and the OTP handling logic. The Wordfence vulnerability analysis provides additional technical details regarding the exploitation mechanics.

Detection Methods for CVE-2025-3844

Indicators of Compromise

• Unexpected AJAX requests to WordPress endpoints containing change_user_meta parameters
• Unusual OTP code modifications or generations in user metadata without corresponding legitimate requests
• Authentication logs showing successful logins via OTP for accounts that did not request OTP codes
• Unauthorized administrative actions or configuration changes following suspicious login activity

Detection Strategies

• Monitor web application firewall (WAF) logs for suspicious AJAX requests targeting the PeproDev Ultimate Profile Solutions plugin endpoints
• Implement anomaly detection for user metadata modifications, particularly OTP-related fields
• Review WordPress authentication logs for OTP-based logins that were not initiated by legitimate password reset or OTP request flows
• Deploy file integrity monitoring to detect any unauthorized changes to the plugin files

Monitoring Recommendations

• Enable detailed logging for WordPress AJAX handlers and plugin activity
• Configure alerts for multiple failed or successful OTP authentications from unfamiliar IP addresses
• Monitor for new administrator accounts or privilege escalations that were not authorized
• Implement rate limiting on AJAX endpoints to detect and mitigate automated exploitation attempts

How to Mitigate CVE-2025-3844

Immediate Actions Required

• Update PeproDev Ultimate Profile Solutions to a version newer than 7.5.2 if a patched version is available
• If no patch is available, disable or remove the plugin immediately until a fix is released
• Audit all WordPress user accounts, especially administrator accounts, for unauthorized access or modifications
• Reset passwords and invalidate sessions for all administrator and privileged accounts
• Review recent login activity and system changes for signs of compromise

Patch Information

Organizations should monitor the WordPress plugin repository and the vendor's official channels for security updates addressing this vulnerability. The vulnerable code is located in login/login.php in versions 1.9.1 through 7.5.2. Until a patched version is confirmed, disabling the plugin is the recommended approach to eliminate the attack surface.

Workarounds

• Disable the PeproDev Ultimate Profile Solutions plugin until an official patch is released
• Implement a Web Application Firewall (WAF) rule to block AJAX requests containing change_user_meta parameters targeting this plugin
• Restrict access to wp-admin/admin-ajax.php from untrusted IP addresses where feasible
• Consider implementing additional authentication controls such as multi-factor authentication (MFA) that does not rely on the vulnerable plugin's OTP mechanism