EMC RSA Security SiteKey allows remote attackers to display the correct image via a man-in-the-middle (MITM) attack in which an attacker-controlled server proxies authentication data to and from a legitimate SiteKey server. NOTE: the vendor disputes the severity of the issue, stating that it is easier to monitor this attack than "attacks against static web pages."
http://www.networkworld.com/newsletters/sec/2007/0402sec2.html