RHSA-2011:0199 - Security Advisory

Topic

Updated krb5 packages that fix two security issues are now available for
Red Hat Enterprise Linux 5.

The Red Hat Security Response Team has rated this update as having
important security impact. Common Vulnerability Scoring System (CVSS) base
scores, which give detailed severity ratings, are available for each
vulnerability from the CVE links in the References section.

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 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)

Red Hat would like to thank the MIT Kerberos Team for reporting these
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 a
backported patch to correct these issues. After installing the updated
packages, the krb5kdc daemon will be restarted automatically.

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
http://kbase.redhat.com/faq/docs/DOC-11259

Affected Products

• Red Hat Enterprise Linux Server 5 x86_64
• Red Hat Enterprise Linux Server 5 ia64
• Red Hat Enterprise Linux Server 5 i386
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 5.6 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 5.6 ia64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 5.6 i386
• Red Hat Enterprise Linux Server - AUS 5.6 ia64
• Red Hat Enterprise Linux Server - AUS 5.6 i386
• Red Hat Enterprise Linux Workstation 5 x86_64
• Red Hat Enterprise Linux Desktop 5 x86_64
• Red Hat Enterprise Linux Desktop 5 i386
• Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 5.6 s390x
• Red Hat Enterprise Linux for Power, big endian 5 ppc
• Red Hat Enterprise Linux for Power, big endian - Extended Update Support 5.6 ppc
• Red Hat Enterprise Linux Server from RHUI 5 x86_64
• Red Hat Enterprise Linux Server from RHUI 5 i386
• Red Hat Enterprise Linux Server - Extended Update Support from RHUI 5.6 x86_64
• Red Hat Enterprise Linux Server - Extended Update Support from RHUI 5.6 i386
• Red Hat Enterprise Linux Server - AUS 5.6 x86_64
• Red Hat Enterprise Linux Workstation 5 i386
• Red Hat Enterprise Linux for IBM z Systems 5 s390x

Fixes

• BZ - 668719 - CVE-2011-0281 krb5: KDC hang when using LDAP backend caused by special principal name (MITKRB5-SA-2011-002)
• BZ - 668726 - CVE-2011-0282 krb5: KDC crash when using LDAP backend caused by a special principal name (MITKRB5-SA-2011-002)

CVEs

• CVE-2011-0281
• CVE-2011-0282

References

• https://access.redhat.com/security/updates/classification/#important
• http://web.mit.edu/kerberos/advisories/MITKRB5-SA-2011-002.txt