jboss-seam.jar in the JBoss Seam 2 framework 2.2.x and earlier, as distributed in Red Hat JBoss Enterprise SOA Platform 4.3.0.CP04 and 5.1.0 and JBoss Enterprise Application Platform (aka JBoss EAP or JBEAP) 4.3.0.CP09 and 5.1.0, does not properly restrict use of Expression Language (EL) statements in FacesMessages during page exception handling, which allows remote attackers to execute arbitrary Java code via a crafted URL to an application.
https://bugzilla.redhat.com/show_bug.cgi?id=692421
http://www.redhat.com/support/errata/RHSA-2011-1251.html
http://www.redhat.com/support/errata/RHSA-2011-1148.html
http://www.redhat.com/support/errata/RHSA-2011-0463.html
http://www.redhat.com/support/errata/RHSA-2011-0462.html