EventPrime <= 4.2.8.4 - Missing Authorization to Unauthenticated Image Upload via 'ep_upload_file_media' AJAX Endpoint

The EventPrime plugin for WordPress is vulnerable to unauthorized image file upload in all versions up to, and including, 4.2.8.4. This is due to the plugin registering the upload_file_media AJAX action as publicly accessible (nopriv-enabled) without implementing any authentication, authorization, or nonce verification despite a nonce being created. This makes it possible for unauthenticated attackers to upload image files to the WordPress uploads directory and create Media Library attachments via the ep_upload_file_media endpoint.