Executive brief
The Frontend Admin plugin for WordPress, which allows site owners to create custom forms for user management, contains a security flaw that allows users to upgrade their own account permissions. By manipulating how user-edit forms are created, an attacker with basic access can grant themselves full administrative control over the website. This could lead to a complete site takeover, data theft, or the installation of malicious software.
Technical details
The vulnerability stems from insufficient authorization checks in the 'role' field update mechanism combined with overly permissive capabilities for the 'admin_form' custom post type. The 'admin_form' post type uses 'capability_type' => 'page', allowing users with Editor-level permissions to create and modify forms. An attacker can bypass UI restrictions in feadmin_get_user_roles() by submitting direct POST data to wp-admin/post.php to include 'administrator' in the 'role_options' array. The pre_update_value() function in class-role.php subsequently fails to verify if the current user has the authority to assign the 'administrator' role, validating only that the role exists in the form's options. This allows an attacker to register as a lower-level user (if public registration is enabled) and escalate their privileges to Administrator.
Affected products
- DynamiApps Frontend Admin by DynamiApps up to and including 3.28.36
Timeline
- 2026-05-15: disclosed
- 2026-05-15: advisory
References
- https://plugins.trac.wordpress.org/browser/acf-frontend-form-element/trunk/main/admin/admin-pages/forms/post-types.php
- https://plugins.trac.wordpress.org/browser/acf-frontend-form-element/trunk/main/frontend/fields/user/class-role.php
- https://plugins.trac.wordpress.org/browser/acf-frontend-form-element/trunk/main/frontend/forms/actions/user.php
- https://plugins.trac.wordpress.org/changeset/3519460
- https://www.wordfence.com/threat-intel/vulnerabilities/id/083accd0-8338-47c6-b396-96679b95dd40?source=cve