Description
Apache Tomcat before 5.5.35, 6.x before 6.0.35, and 7.x before 7.0.23 computes hash values for form parameters without restricting the ability to trigger hash collisions predictably, which allows remote attackers to cause a denial of service (CPU consumption) by sending many crafted parameters.
Remediation
References
http://mail-archives.apache.org/mod_mbox/tomcat-announce/201112.mbox/%3c4EFB9800.5010106%40apache.org%3e
http://marc.info/?l=bugtraq&m=132871655717248&w=2
http://marc.info/?l=bugtraq&m=132871655717248&w=2
http://marc.info/?l=bugtraq&m=133294394108746&w=2
http://marc.info/?l=bugtraq&m=133294394108746&w=2
http://marc.info/?l=bugtraq&m=136485229118404&w=2
http://marc.info/?l=bugtraq&m=136485229118404&w=2
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-2012-0089.html
http://rhn.redhat.com/errata/RHSA-2012-0325.html
http://rhn.redhat.com/errata/RHSA-2012-0406.html
http://secunia.com/advisories/48549
http://secunia.com/advisories/48790
http://secunia.com/advisories/48791
http://secunia.com/advisories/54971
http://secunia.com/advisories/55115
http://tomcat.apache.org/tomcat-7.0-doc/changelog.html
http://www.debian.org/security/2012/dsa-2401
http://www.kb.cert.org/vuls/id/903934
http://www.nruns.com/_downloads/advisory28122011.pdf
http://www.ocert.org/advisories/ocert-2011-003.html
http://www.securityfocus.com/bid/51200
https://bugzilla.redhat.com/show_bug.cgi?id=750521
https://github.com/FireFart/HashCollision-DOS-POC/blob/master/HashtablePOC.py
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A18886
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