(RHSA-2010:0423) Important: 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 discovered in the MIT Kerberos Generic
Security Service Application Program Interface (GSS-API) library. A remote,
authenticated attacker could use this flaw to crash any server application
using the GSS-API authentication mechanism, by sending a specially-crafted
GSS-API token with a missing checksum field. (CVE-2010-1321)

Red Hat would like to thank the MIT Kerberos Team for responsibly reporting
this issue. Upstream acknowledges Shawn Emery of Oracle as the original
reporter.

All krb5 users should upgrade to these updated packages, which contain a
backported patch to correct this issue. All running services using the MIT
Kerberos libraries must be restarted for the update to take effect.