Description
WordPress Plugin Registration Forms-User Registration Forms, Invitation-Based Registrations, Front-end User Profile, Login Form & Content Restriction is prone to an open redirect vulnerability because the application fails to properly verify user-supplied input. Exploiting this issue may allow attackers to redirect users to arbitrary web sites and conduct phishing attacks; other attacks are also possible. WordPress Plugin Registration Forms-User Registration Forms, Invitation-Based Registrations, Front-end User Profile, Login Form & Content Restriction version 3.7.2.3 is vulnerable; prior versions may also be affected.
Remediation
Update to plugin version 3.7.2.4 or latest
References
https://sploitus.com/exploit?id=WPEX-ID:F6EFA32F-51DF-44B4-BBBA-E67ED5785DD4
https://plugins.svn.wordpress.org/pie-register/trunk/readme.txt