Fixed in Apache Tomcat 7.0.23

Important: Denial of service CVE-2012-0022

Analysis of the recent hash collision vulnerability identified unrelated inefficiencies with Apache Tomcat’s handling of large numbers of parameters and parameter values. These inefficiencies could allow an attacker, via a specially crafted request, to cause large amounts of CPU to be used which in turn could create a denial of service. The issue was addressed by modifying the Tomcat parameter handling code to efficiently process large numbers of parameters and parameter values.

This was fixed in revisions 1189899, 1190372, 1190482, 1194917, 1195225, 1195226, 1195537, 1195909, 1195944, 1195951, 1195977 and 1198641.

This was identified by the Tomcat security team on 21 October 2011 and made public on 17 January 2012.

Affects: 7.0.0-7.0.22