krb5 security update

CentOS Errata and Security Advisory CESA-2011:1790

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.

Merged security bulletin from advisories:
https://lists.centos.org/pipermail/centos-announce/2011-December/080506.html

Affected packages:
krb5-devel
krb5-libs
krb5-pkinit-openssl
krb5-server
krb5-server-ldap
krb5-workstation

Upstream details at:
https://access.redhat.com/errata/RHSA-2011:1790