The Backup Migration plugin for WordPress is vulnerable to PHP Object Injection in all versions up to, and including, 1.4.6 via deserialization of untrusted input in the 'recursive_unserialize_replace' function. This makes it possible for unauthenticated attackers to inject a PHP Object. The additional presence of a POP chain allows attackers to delete arbitrary files, retrieve sensitive data, or execute code. An administrator must create a staging site in order to trigger the exploit.