do_tgs_req.c in the Key Distribution Center (KDC) in MIT Kerberos 5 (aka krb5) 1.11 before 1.11.4, when a single-component realm name is used, allows remote authenticated users to cause a denial of service (daemon crash) via a TGS-REQ request that triggers an attempted cross-realm referral for a host-based service principal.
https://bugzilla.redhat.com/show_bug.cgi?id=1030743
http://web.mit.edu/kerberos/krb5-1.11/README-1.11.4.txt
http://lists.opensuse.org/opensuse-updates/2013-12/msg00026.html