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."
http://rhn.redhat.com/errata/RHSA-2012-0074.html
http://rhn.redhat.com/errata/RHSA-2012-0075.html
http://rhn.redhat.com/errata/RHSA-2012-0076.html
http://rhn.redhat.com/errata/RHSA-2012-0077.html
http://rhn.redhat.com/errata/RHSA-2012-0078.html
http://rhn.redhat.com/errata/RHSA-2012-0325.html