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Red Hat Linux Advisory: kerberos

Apr 02, 2003, 16:39 (0 Talkback[s])

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                   Red Hat Security Advisory

Synopsis:          Updated kerberos packages fix various vulnerabilities
Advisory ID:       RHSA-2003:091-01
Issue date:        2003-04-02
Updated on:        2003-04-02
Product:           Red Hat Linux
Keywords:          krb5
Cross references:  RHSA-2003:051 RHSA-2003:052
Obsoletes:         RHSA-2003:021
CVE Names:         CAN-2003-0028 CAN-2003-082 CAN-2003-0138 CAN-2003-0139

1. Topic:

Updated Kerberos packages for Red Hat Linux 9 fix a number of
vulnerabilities found in MIT Kerberos.

2. Relevant releases/architectures:

Red Hat Linux 9 - i386

3. Problem description:

Kerberos is a network authentication system. The MIT Kerberos team
released an advisory describing a number of vulnerabilities that affect the
kerberos packages shipped as part of Red Hat Linux 9. These issues include:

Vulnerabilities have been found in the triple-DES key support found in the
implementation of the Kerberos IV authentication protocol included in MIT
Kerberos. The Common Vulnerabilities and Exposures project has assigned
the name CAN-2003-0139 to this issue.

Vulnerabilities have been found in the Kerberos IV authentication protocol
which allow an attacker with knowledge of a cross-realm key, which is
shared with another realm, to impersonate any principal in that realm to
any service in that realm. This vulnerability can only be closed by
disabling cross-realm authentication in Kerberos IV (CAN-2003-0138).

Vulnerabilities have been found in the RPC library used by the kadmin
service in Kerberos 5. A faulty length check in the RPC library exposes
kadmind to an integer overflow which can be used to crash kadmind

The Key Distribution Center (KDC) allows remote, authenticated attackers
to cause a denial of service (crash) on KDCs within the same realm via a
certain protocol request that causes the KDC to corrupt its heap

All users of Kerberos are advised to upgrade to these errata packages,
which disable cross-realm authentication by default for Kerberos IV and
which contain patches that correct these issues.

4. Solution:

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

To update all RPMs for your particular architecture, run:

rpm -Fvh [filenames]

where [filenames] is a list of the RPMs you wish to upgrade.  Only those
RPMs which are currently installed will be updated.  Those RPMs which are
not installed but included in the list will not be updated.  Note that you
can also use wildcards (*.rpm) if your current directory only contains the
desired RPMs.

Please note that this update is also available via Red Hat Network.  Many
people find this an easier way to apply updates.  To use Red Hat Network,
launch the Red Hat Update Agent with the following command:


This will start an interactive process that will result in the appropriate
RPMs being upgraded on your system.

5. RPMs required:

Red Hat Linux 9:



6. Verification:

MD5 sum                          Package Name
a8520da58b790a356d0a94ae75f7957b 9/en/os/SRPMS/krb5-1.2.7-14.src.rpm
49e7783cb50c3694411b7856d098eff5 9/en/os/i386/krb5-devel-1.2.7-14.i386.rpm
6cb5040d3a4bd21a801e8c1e5da6388d 9/en/os/i386/krb5-libs-1.2.7-14.i386.rpm
8eb2a755c2fdf52b779960ec66cc6783 9/en/os/i386/krb5-server-1.2.7-14.i386.rpm
bbcde88fa4f273c7c45a927dc5b40d58 9/en/os/i386/krb5-workstation-1.2.7-14.i386.rpm

These packages are GPG signed by Red Hat for security.  Our key is
available at

You can verify each package with the following command:
    rpm --checksig -v 

If you only wish to verify that each package has not been corrupted or
tampered with, examine only the md5sum with the following command:

7. References:

8. Contact:

The Red Hat security contact is <<A HREF="">>.  More contact
details at

Copyright 2003 Red Hat, Inc.