CVE-2025-3282 is an authorization bypass vulnerability categorized under CWE-639 (Authorization Bypass Through User-Controlled Key) found in the wpeverest User Registration & Membership plugin for WordPress. The vulnerability exists in the function user_registration_membership_register_member(), which fails to validate the 'membership_id' parameter supplied by users. This lack of validation allows unauthenticated attackers to manipulate the membership_id field to update any user's membership status arbitrarily, including switching to active or inactive membership types. The flaw is an insecure direct object reference (IDOR), where the application trusts user input to identify and modify membership records without verifying the requester's authorization. The vulnerability affects all plugin versions up to and including 4.1.3. The CVSS v3.1 base score is 5.3 (medium severity), reflecting that the attack vector is network-based, requires no privileges or user interaction, and impacts integrity by allowing unauthorized modification of membership data. There is no impact on confidentiality or availability. No patches or known exploits are currently available. This vulnerability could be leveraged to escalate privileges within membership-based WordPress sites, granting unauthorized access to premium content or features. The root cause is insufficient access control checks on a user-controlled parameter, a common security oversight in web applications handling user roles and memberships.

The primary impact of CVE-2025-3282 is unauthorized modification of user membership statuses within WordPress sites using the vulnerable plugin. Attackers can escalate privileges by assigning themselves or others higher-tier memberships or downgrade memberships to inactive states, disrupting legitimate user access. This can lead to unauthorized access to premium content, services, or features reserved for paying or verified members, potentially causing revenue loss, reputational damage, and violation of user trust. While confidentiality and availability are not directly affected, integrity of membership data is compromised. Organizations relying on membership controls for access management are at risk of unauthorized privilege escalation. The vulnerability can be exploited remotely without authentication, increasing the attack surface. Although no known exploits are reported, the ease of exploitation and widespread use of WordPress and this plugin increase the likelihood of future attacks. This threat is particularly relevant for membership-based websites such as e-learning platforms, subscription services, and community portals.

To mitigate CVE-2025-3282, organizations should immediately audit and restrict access control checks on all user-controlled parameters, especially 'membership_id' in the affected plugin. Implement strict server-side validation to ensure that any membership modification requests are authorized and originate from authenticated users with appropriate privileges. Until an official patch is released, consider temporarily disabling the plugin or restricting its functionality to trusted administrators only. Employ Web Application Firewalls (WAFs) with custom rules to detect and block suspicious requests attempting to manipulate membership_id parameters. Monitor logs for unusual membership changes or access patterns. Additionally, apply the principle of least privilege in membership role assignments and regularly review user roles for anomalies. Stay updated with vendor advisories for patches and apply them promptly once available. Conduct penetration testing focused on authorization bypass scenarios to identify similar weaknesses in other plugins or custom code.