Multiple SQL injection vulnerabilities in the ratings module in the Users Ultra plugin before 1.5.16 for WordPress allow remote attackers to execute arbitrary SQL commands via the (1) data_target or (2) data_vote parameter in a rating_vote (wp_ajax_nopriv_rating_vote) action to wp-admin/admin-ajax.php.
https://wordpress.org/plugins/users-ultra/changelog/
http://www.securityfocus.com/bid/75052
http://www.securityfocus.com/archive/1/535690/100/0/threaded