source: http://www.securityfocus.com/bid/61140/info

Pie Register plugin for WordPress is prone to multiple cross-site scripting vulnerabilities.

An attacker may leverage these issues to execute arbitrary script code in the browser of an unsuspecting user in the context of the affected site. This may allow the attacker to steal cookie-based authentication credentials and launch other attacks.

Pie Register 1.30 is vulnerable; other versions may also be affected. 

<?php echo $_POST['pass1'];?>
<?php echo $_POST['pass2'];?>