Everest Forms – Contact Form, Payment Form, Quiz, Survey & Custom Form Builder with AI < 3.5.3 - Missing Authorization to Authenticated (Delegated+) Arbitrary Plugin Activation via REST API and AJAX Endpoints

Description

The Everest Forms – Contact Form, Payment Form, Quiz, Survey & Custom Form Builder with AI plugin for WordPress is vulnerable to authorization bypass in all versions up to, and including, 3.5.2. This is due to the plugin not properly verifying that a user is authorized to perform an action. This makes it possible for authenticated attackers, with delegated form management access and above, to activate arbitrary already-installed WordPress plugins — including previously deactivated or vulnerable plugins — without holding the core activate_plugins capability. Exploitation requires the target user to hold a delegated Everest Forms capability (manage_everest_forms, everest_forms_create_forms, or everest_forms_view_forms), which the plugin's own roles and permissions tool allows administrators to assign to non-administrator roles such as Author; the nonces required to exploit the AJAX handlers are emitted on EVF admin pages accessible to any such delegated user.