The (1) kadm5_create_principal_3 and (2) kadm5_modify_principal functions in lib/kadm5/srv/svr_principal.c in kadmind in MIT Kerberos 5 (aka krb5) 1.12.x and 1.13.x before 1.13.4 and 1.14.x before 1.14.1 allow remote authenticated users to cause a denial of service (NULL pointer dereference and daemon crash) by specifying KADM5_POLICY with a NULL policy name.
https://github.com/krb5/krb5/commit/b863de7fbf080b15e347a736fdda0a82d42f4f6b
http://www.securitytracker.com/id/1034915
http://www.oracle.com/technetwork/topics/security/linuxbulletinapr2016-2952096.html
http://www.debian.org/security/2016/dsa-3466
http://rhn.redhat.com/errata/RHSA-2016-0532.html
http://lists.opensuse.org/opensuse-updates/2016-02/msg00110.html
http://lists.opensuse.org/opensuse-updates/2016-02/msg00059.html