(RHSA-2011:1790) Moderate: krb5 security update

Kerberos is a network authentication system which allows clients and
servers to authenticate to each other using symmetric encryption and a
trusted third-party, the Key Distribution Center (KDC).

A NULL pointer dereference flaw was found in the way the MIT Kerberos KDC
processed certain TGS (Ticket-granting Server) requests. A remote,
authenticated attacker could use this flaw to crash the KDC via a
specially-crafted TGS request. (CVE-2011-1530)

Red Hat would like to thank the MIT Kerberos project for reporting this
issue.

All krb5 users should upgrade to these updated packages, which contain a
backported patch to correct this issue. After installing the updated
packages, the krb5kdc daemon will be restarted automatically.