Red Hat Security Advisory 2012-0325-01 - JBoss Web is a web container based on Apache Tomcat. A flaw was found in the way JBoss Web handled UTF-8 surrogate pair characters. If JBoss Web was hosting an application with UTF-8 character encoding enabled, or that included user-supplied UTF-8 strings in a response, a remote attacker could use this flaw to cause a denial of service on the JBoss Web server. It was found that the Java hashCode() method implementation was susceptible to predictable hash collisions. A remote attacker could use this flaw to cause JBoss Web to use an excessive amount of CPU time by sending an HTTP request with a large number of parameters whose names map to the same hash value. Various other issues were addressed.
d22d787c4112a659c3c9e4f42170042f88ea6052206c4cfb93c8a3c97eae2892