The Frontend File Manager plugin for WordPress is vulnerable to Unauthenticated Stored Cross-Site Scripting in versions up to, and including, 18.2. This is due to lacking authentication protections and santisation all on the wpfm_edit_file_title_desc AJAX action. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.
The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.