RHSA-2011:1790

Problem Description:

Updated krb5 packages that fix one security issue are now available for
Red Hat Enterprise Linux 6.

The Red Hat Security Response Team has rated this update as having moderate
security impact. A Common Vulnerability Scoring System (CVSS) base score,
which gives a detailed severity rating, is available from the CVE link in
the References section.

2. Relevant releases/architectures:

Red Hat Enterprise Linux Desktop (v. 6) - i386, x86_64
Red Hat Enterprise Linux Desktop Optional (v. 6) - i386, x86_64
Red Hat Enterprise Linux HPC Node (v. 6) - x86_64
Red Hat Enterprise Linux HPC Node Optional (v. 6) - x86_64
Red Hat Enterprise Linux Server (v. 6) - i386, ppc64, s390x, x86_64
Red Hat Enterprise Linux Workstation (v. 6) - i386, x86_64

3. Description:

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.

4. Solution:

Before applying this update, make sure all previously-released errata
relevant to your system have been applied.

This update is available via the Red Hat Network. Details on how to
use the Red Hat Network to apply this update are available at
https://access.redhat.com/kb/docs/DOC-11259

5. Bugs fixed (http://bugzilla.redhat.com/):

753748 - CVE-2011-1530 krb5 (krb5kdc): NULL pointer dereference in the TGS handling (MITKRB5-SA-2011-007)