The User Registration plugin for WordPress is vulnerable to PHP Object Injection in versions up to, and including, 3.0.1 via deserialization of untrusted input from the 'profile-pic-url' parameter. This allows authenticated attackers, with subscriber-level permissions and above, to inject a PHP Object. No POP chain is present in the vulnerable plugin. If a POP chain is present via an additional plugin or theme installed on the target system, it could allow the attacker to delete arbitrary files, retrieve sensitive data, or execute code.