Arbitrary file deletion in Acadlix LMS WordPress plugin

The Acadlix LMS – AI Quiz Maker, Online Exam & Course Plugin for WordPress plugin for WordPress is vulnerable to arbitrary file deletion due to insufficient file path validation in the post_delete_assessment_file_by_id function in all versions up to, and including, 1.1.9. This makes it possible for authenticated attackers, with subscriber-level access and above, to delete arbitrary files on the server, which can easily lead to remote code execution when the right file is deleted (such as wp-config.php). The route's permission callback only verifies a generic wp_rest nonce that the plugin itself emits inside the public acadlixOptions JavaScript object on every frontend page, effectively reducing the authentication requirement to unauthenticated.