Red Hat Security Advisory 2012-0475-01 - Apache Tomcat is a servlet container for the Java Servlet and JavaServer Pages technologies. It was found that the Java hashCode() method implementation was susceptible to predictable hash collisions. A remote attacker could use this flaw to cause Tomcat 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. This update introduces a limit on the number of parameters processed per request to mitigate this issue. The default limit is 512 for parameters and 128 for headers. These defaults can be changed by setting the org.apache.tomcat.util.http.Parameters.MAX_COUNT and org.apache.tomcat.util.http.MimeHeaders.MAX_COUNT system properties.