The Advanced File Manager plugin for WordPress is vulnerable to arbitrary file uploads due to missing file type validation in the 'fmalocalfilesystem' function in versions 5.2.12 to 5.2.13. This makes it possible for authenticated attackers, with Subscriber-level access and above and upload permissions granted by an administrator, to upload arbitrary files on the affected site's server which may make remote code execution possible. The function can be exploited only if the "Display .htaccess?" setting is enabled.