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.