Frontend File Manager <= 21.3 is vulnerable to File Upload via Cross-Site Request Forgery (CSRF) vulnerability

The "Frontend File Manager Plugin" plugin for WordPress is vulnerable to Cross-Site Request Forgery in versions up to, and including, 21.2. This is due to missing or incorrect nonce validation on the wpfm_upload_file function. This makes it possible for unauthenticated attackers to upload files on behalf of other users, via forged request granted they can trick such a user into performing an action such as clicking on a link.