The File Manager Pro – Filester plugin for WordPress is vulnerable to arbitrary file uploads due to missing validation in the 'fsConnector' function in all versions up to, and including, 1.8.6. This makes it possible for authenticated attackers, with Subscriber-level access and above, and granted permissions by an Administrator, to upload a new .htaccess file allowing them to subsequently upload arbitrary files on the affected site's server which may make remote code execution possible.