AI Engine <= 3.3.2 - Authenticated (Editor+) Arbitrary File Upload via 'filename' Parameter in update_media_metadata Endpoint

The AI Engine – The Chatbot and AI Framework for WordPress plugin for WordPress is vulnerable to arbitrary file uploads due to missing file type validation in the `rest_helpers_update_media_metadata` function in all versions up to, and including, 3.3.2. This makes it possible for authenticated attackers, with Editor-level access and above, to upload arbitrary files on the affected site's server which may make remote code execution possible. The attacker can upload a benign image file, then use the `update_media_metadata` endpoint to rename it to a PHP file, creating an executable PHP file in the uploads directory.