Cross-site scripting (XSS) vulnerability in wp-comments-post.php in WordPress 3.3.x before 3.3.1, when Internet Explorer is used, allows remote attackers to inject arbitrary web script or HTML via the query string in a POST operation that is not properly handled by the "Duplicate comment detected" feature.
https://wordpress.org/news/2012/01/wordpress-3-3-1/
https://euvd.enisa.europa.eu/vulnerability/EUVD-2012-0323
http://www.securitytracker.com/id?1026542
http://www.securityfocus.com/bid/51237
http://oldmanlab.blogspot.com/2012/01/wordpress-33-xss-vulnerability.html