Ultimate Member – User Profile, User Registration, Login & Membership Plugin <= 2.5.0 - Authenticated (Admin+) Limited Remote Code Execution via um_populate_dropdown_options

The Ultimate Member plugin for WordPress is vulnerable to Remote Code Execution in versions up to, and including, 2.5.0 via the populate_dropdown_options function that accepts user supplied input and passes it through call_user_func(). This is restricted to non-parameter PHP functions like phpinfo(); since user supplied parameters are not passed through the function. This makes it possible for authenticated attackers, with administrative privileges, to execute code on the server.