(RHSA-2011:0200) 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 found in the way the MIT Kerberos KDC
processed principal names that were not null terminated, when the KDC was
configured to use an LDAP back end. A remote attacker could use this flaw
to crash the KDC via a specially-crafted request. (CVE-2011-0282)

A denial of service flaw was found in the way the MIT Kerberos KDC
processed certain principal names when the KDC was configured to use an
LDAP back end. A remote attacker could use this flaw to cause the KDC to
hang via a specially-crafted request. (CVE-2011-0281)

A denial of service flaw was found in the way the MIT Kerberos V5 slave KDC
update server (kpropd) processed certain update requests for KDC database
propagation. A remote attacker could use this flaw to terminate the kpropd
daemon via a specially-crafted update request. (CVE-2010-4022)

Red Hat would like to thank the MIT Kerberos Team for reporting the
CVE-2011-0282 and CVE-2011-0281 issues. Upstream acknowledges Kevin
Longfellow of Oracle Corporation as the original reporter of the
CVE-2011-0281 issue.

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