Red Hat Security Advisory 2014-1245-01 – Kerberos is an authentication system which allows clients and services to authenticate to each other with the help of a trusted third party, a Kerberos Key Distribution Center. It was found that if a KDC served multiple realms, certain requests could cause the setup_server_realm() function to dereference a NULL pointer. A remote, unauthenticated attacker could use this flaw to crash the KDC using a specially crafted request. A NULL pointer dereference flaw was found in the MIT Kerberos SPNEGO acceptor for continuation tokens. A remote, unauthenticated attacker could use this flaw to crash a GSSAPI-enabled server application.