The web browser plug-in in IcedTea-Web 1.0.x before 1.0.6 and 1.1.x before 1.1.4 allows remote attackers to bypass the Same Origin Policy (SOP) and execute arbitrary script or establish network connections to unintended hosts via an applet whose origin has the same second-level domain, but a different sub-domain than the targeted domain.
https://bugzilla.redhat.com/show_bug.cgi?id=742515
http://www.ubuntu.com/usn/USN-1263-1
http://www.securityfocus.com/bid/50610
http://www.debian.org/security/2012/dsa-2420
http://rhn.redhat.com/errata/RHSA-2011-1441.html
http://lists.opensuse.org/opensuse-updates/2012-03/msg00028.html
http://dbhole.wordpress.com/2011/11/08/icedtea-web-1-0-6-and-1-1-4-security-releases-released/