JBoss Web, as used in Red Hat JBoss Communications Platform before 5.1.3, Enterprise Web Platform before 5.1.2, Enterprise Application Platform before 5.1.2, and other products, allows remote attackers to cause a denial of service (infinite loop) via vectors related to a crafted UTF-8 and a "surrogate pair character" that is "at the boundary of an internal buffer."
https://bugzilla.redhat.com/show_bug.cgi?id=767871
http://www.securityfocus.com/bid/51829
http://rhn.redhat.com/errata/RHSA-2012-0325.html
http://rhn.redhat.com/errata/RHSA-2012-0078.html
http://rhn.redhat.com/errata/RHSA-2012-0077.html
http://rhn.redhat.com/errata/RHSA-2012-0076.html