Double free vulnerability in do_tgs_req.c in the Key Distribution Center (KDC) in MIT Kerberos 5 (aka krb5) 1.7.x and 1.8.x before 1.8.2 allows remote authenticated users to cause a denial of service (daemon crash) or possibly execute arbitrary code via a request associated with (1) renewal or (2) validation.
http://www.vupen.com/english/advisories/2010/1481
http://www.vupen.com/english/advisories/2010/1192
http://www.vupen.com/english/advisories/2010/1001
http://www.ubuntu.com/usn/USN-940-1
http://www.securityfocus.com/archive/1/510843/100/0/threaded
http://web.mit.edu/kerberos/advisories/MITKRB5-SA-2010-004.txt
http://support.apple.com/kb/HT4188
http://securitytracker.com/id?1023904
http://secunia.com/advisories/40220
http://secunia.com/advisories/39784
http://secunia.com/advisories/39656
http://lists.opensuse.org/opensuse-security-announce/2010-04/msg00006.html
http://lists.apple.com/archives/security-announce/2010//Jun/msg00001.html