CVE-2025-4334 in Simple User Registration Plugin
Summary
by MITRE • 06/26/2025
The Simple User Registration plugin for WordPress is vulnerable to Privilege Escalation in all versions up to, and including, 6.3. This is due to insufficient restrictions on user meta values that can be supplied during registration. This makes it possible for unauthenticated attackers to register as an administrator.
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Analysis
by VulDB Data Team • 06/27/2025
The Simple User Registration plugin for WordPress presents a critical privilege escalation vulnerability identified as CVE-2025-4334 affecting all versions up to and including 6.3. This vulnerability stems from inadequate validation of user meta values during the registration process, creating a pathway for unauthenticated attackers to escalate their privileges and assume administrative roles within the WordPress environment. The flaw represents a fundamental breakdown in the plugin's access control mechanisms, allowing malicious actors to manipulate registration parameters and gain elevated system permissions without proper authentication.
The technical implementation of this vulnerability resides in the plugin's insufficient input sanitization and validation routines. When users attempt to register through the plugin's interface, the system fails to properly validate or restrict the meta values associated with user accounts. This weakness enables attackers to inject specially crafted meta data during registration that bypasses normal user role restrictions. The vulnerability aligns with CWE-285, which addresses improper authorization issues, and specifically demonstrates how inadequate access control validation can lead to privilege escalation. Attackers can exploit this by manipulating the registration form to include administrative meta values, effectively creating administrator accounts without requiring legitimate administrative credentials.
The operational impact of CVE-2025-4334 extends far beyond simple account creation, as successful exploitation grants full administrative control over WordPress installations. This includes complete access to site content, user management capabilities, plugin and theme modifications, and the ability to execute arbitrary code within the WordPress environment. The vulnerability is particularly dangerous because it operates without requiring authentication, making it an attractive target for automated exploitation tools and mass scanning campaigns. Organizations running affected versions of the Simple User Registration plugin face significant risk of complete system compromise, data theft, and potential use as a foothold for broader network attacks.
Mitigation strategies for this vulnerability require immediate action including the mandatory update of the Simple User Registration plugin to the latest version that addresses the privilege escalation flaw. System administrators should also implement additional security measures such as rate limiting for registration attempts, monitoring of unusual user registration patterns, and implementation of web application firewalls to detect and block exploitation attempts. The vulnerability demonstrates the importance of proper input validation and access control enforcement in web applications, aligning with ATT&CK technique T1078 which covers valid accounts and T1548 which covers abuse of privileges. Organizations should also conduct thorough security assessments of their WordPress installations to identify other potential vulnerabilities and ensure proper patch management processes are in place to prevent similar issues in the future.