The RegistrationMagic – Custom Registration Forms, User Registration, Payment, and User Login plugin for WordPress is vulnerable to PHP Object Injection in all versions up to 3.7.9.3 (exclusive) via deserialization of untrusted input from the isexpiredbydate() function. This makes it possible for unauthenticated attackers to inject a PHP Object. The additional presence of a POP chain allows attackers to fetch a remote file and install it on the site.