SuSE Linux Advisory: heimdal
Oct 01, 2002, 00:59 (0 Talkback[s])
SuSE Security Announcement
Date: Mon Sep 30 17:00:00 CEST 2002
Affected products: SuSE Linux 7.2, 7.3, 8.0,
SuSE eMail Server,
SuSE Linux Connectivity Server,
SuSE Linux Enterprise Server 7,
SuSE Linux Office Server
Vulnerability Type: remote command execution
Severity (1-10): 8
SuSE default package: Yes
Cross References: http://www.pdc.kth.se/heimdal
Content of this advisory:
1) security vulnerability resolved: Various overflows in heimdal.
problem description, discussion, solution and upgrade information
2) pending vulnerabilities, solutions, workarounds:
3) standard appendix (further information)
1) problem description, brief discussion, solution, upgrade information
The Heimdal package is a free Kerberos implementation offering flexible
authentication mechanisms based on the Kerberos 5 and Kerberos 4 scheme.
The SuSE Security Team has reviewed critical parts of the Heimdal
package such as the kadmind and kdc server. While doing so several
possible buffer overflows and other bugs have been uncovered and fixed.
Remote attackers can probably gain remote root access on unpatched systems.
Since these services run usually on authentication servers we consider
these bugs to be very serious. An update is strongly recommended if you are
using the Heimdal package.
Please download the update package for your distribution and verify its
integrity by the methods listed in section 3) of this announcement.
Then, install the package using the command "rpm -Fhv file.rpm" to apply
Our maintenance customers are being notified individually. The packages
are being offered to install from the maintenance web.
To be sure the update takes effect you have to restart the services which
belong to the heimdal package. As root execute the command
If you are running other Kerberos based services such as hpropd make sure
you also restart them as well.
i386 Intel Platform:
PPC Power PC Platform:
2) Pending vulnerabilities in SuSE Distributions and Workarounds:
Bufferoverflows have recently been discovered in these packages. They allow
attackers to execute arbitrary code with the privileges of the user
viewing special crafted documents created by the attacker. New packgaes will
soon be available on our ftp servers.
Fetchmail contains remotely exploitable overflows in the mail header
parsing functions. In depth discussion of these problems can be found at
New packages will soon be available on our ftp servers.
3) standard appendix: authenticity verification, additional information
- Package authenticity verification:
SuSE update packages are available on many mirror ftp servers all over
the world. While this service is being considered valuable and important
to the free and open source software community, many users wish to be
sure about the origin of the package and its content before installing
the package. There are two verification methods that can be used
independently from each other to prove the authenticity of a downloaded
file or rpm package:
1) md5sums as provided in the (cryptographically signed) announcement.
2) using the internal gpg signatures of the rpm package.
1) execute the command
after you downloaded the file from a SuSE ftp server or its mirrors.
Then, compare the resulting md5sum with the one that is listed in the
announcement. Since the announcement containing the checksums is
cryptographically signed (usually using the key email@example.com),
the checksums show proof of the authenticity of the package.
We disrecommend to subscribe to security lists which cause the
email message containing the announcement to be modified so that
the signature does not match after transport through the mailing
Downsides: You must be able to verify the authenticity of the
announcement in the first place. If RPM packages are being rebuilt
and a new version of a package is published on the ftp server, all
md5 sums for the files are useless.
2) rpm package signatures provide an easy way to verify the authenticity
of an rpm package. Use the command
rpm -v --checksig <file.rpm>
to verify the signature of the package, where <file.rpm> is the
filename of the rpm package that you have downloaded. Of course,
package authenticity verification can only target an un-installed rpm
a) gpg is installed
b) The package is signed using a certain key. The public part of this
key must be installed by the gpg program in the directory
~/.gnupg/ under the user's home directory who performs the
signature verification (usually root). You can import the key
that is used by SuSE in rpm packages for SuSE Linux by saving
this announcement to a file ("announcement.txt") and
running the command (do "su -" to be root):
gpg --batch; gpg < announcement.txt | gpg --import
SuSE Linux distributions version 7.1 and thereafter install the
key "firstname.lastname@example.org" upon installation or upgrade, provided that
the package gpg is installed. The file containing the public key
is placed at the top-level directory of the first CD (pubring.gpg)
and at ftp://ftp.suse.com/pub/suse/pubring.gpg-build.suse.de .
- SuSE runs two security mailing lists to which any interested party may
- general/linux/SuSE security discussion.
All SuSE security announcements are sent to this list.
To subscribe, send an email to
- SuSE's announce-only mailing list.
Only SuSE's security announcements are sent to this list.
To subscribe, send an email to
For general information or the frequently asked questions (faq)
send mail to:
SuSE's security contact is <email@example.com> or <firstname.lastname@example.org>.
The <email@example.com> public key is listed below.
The information in this advisory may be distributed or reproduced,
provided that the advisory is not modified in any way. In particular,
it is desired that the clear-text signature shows proof of the
authenticity of the text.
SuSE Linux AG makes no warranties of any kind whatsoever with respect
to the information contained in this security advisory.
Type Bits/KeyID Date User ID
pub 2048R/3D25D3D9 1999-03-06 SuSE Security Team <firstname.lastname@example.org>
pub 1024D/9C800ACA 2000-10-19 SuSE Package Signing Key <email@example.com>