Use-after-free vulnerability in kadmin/server/server_stubs.c in kadmind in MIT Kerberos 5 (aka krb5) 1.5 through 1.6.3 allows remote authenticated users to cause a denial of service (daemon crash) via a request from a kadmin client that sends an invalid API version number.
http://www.debian.org/security/2010/dsa-2031
http://web.mit.edu/kerberos/advisories/MITKRB5-SA-2010-003.txt
http://ubuntu.com/usn/usn-924-1
http://lists.opensuse.org/opensuse-security-announce/2010-04/msg00002.html
http://lists.fedoraproject.org/pipermail/package-announce/2010-April/038556.html