The Frontend File Manager plugin for WordPress is vulnerable to Unauthenticated HTML Injection in versions up to, and including, 18.2. This is due to lacking authentication protections on the wpfm_send_file_in_email AJAX action. This makes it possible for unauthenticated attackers to send emails using the site with a custom subject, recipient email, and body with unsanitized HTML content. This effectively lets the attacker use the site as a spam relay.

The Frontend File Manager plugin for WordPress is vulnerable to Privilege Escalation in versions up to, and including, 18.2. This is due to lacking mishandling the use of user IDs that is accessible by the visitor. This makes it possible for unauthenticated or authenticated attackers to access the information and privileges of other users, including 'guest users', in their own category (authenticated, or unauthenticated guests).

The Frontend File Manager Plugin WordPress plugin before 21.4 does not have CSRF check when uploading files, which could allow attackers to make logged in users upload files on their behalf

The Frontend File Manager Plugin WordPress plugin before 21.3 allows any authenticated users, such as subscriber, to rename a file to an arbitrary extension, like PHP, which could allow them to basically be able to upload arbitrary files on the server and achieve RCE

The Frontend File Manager Plugin WordPress plugin before 21.3 allows any unauthenticated user to rename uploaded files from users. Furthermore, due to the lack of validation in the destination filename, this could allow allow them to change the content of arbitrary files on the web server