The NTLM component in Squid 2.5.STABLE7 and earlier allows remote attackers to cause a denial of service (crash) via a malformed NTLM type 3 message that triggers a NULL dereference.
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A11646
http://www.trustix.org/errata/2005/0003/
http://www.squid-cache.org/Versions/v2/2.5/bugs/#squid-2.5.STABLE7-fakeauth_auth
http://www.securityfocus.com/bid/12220
http://www.redhat.com/support/errata/RHSA-2005-061.html
http://www.redhat.com/support/errata/RHSA-2005-060.html
http://www.novell.com/linux/security/advisories/2005_06_squid.html
http://securitytracker.com/id?1012818
http://security.gentoo.org/glsa/glsa-200501-25.xml