Description
WordPress Plugin Registration Forms-User Registration Forms, Invitation-Based Registrations, Front-end User Profile, Login Form & Content Restriction is prone to an SQL injection vulnerability because it fails to sufficiently sanitize user-supplied data before using it in an SQL query. Exploiting this issue could allow an attacker to compromise the application, access or modify data, or exploit latent vulnerabilities in the underlying database. WordPress Plugin Registration Forms-User Registration Forms, Invitation-Based Registrations, Front-end User Profile, Login Form & Content Restriction version 3.1.1 is vulnerable; prior versions may also be affected.
Remediation
Update to plugin version 3.1.2 or latest
References
https://github.com/CBiu/wp-plugins-vuln/blob/master/SQLi/pie-register.md
https://plugins.svn.wordpress.org/pie-register/trunk/readme.txt