SUSE Security Announcement – SuSE-SA:2004:019

SUSE Security Announcement

Package: dhcp/dhcp-server
Announcement-ID: SuSE-SA:2004:019
Date: Tuesday, Jun 22st 2004 21:00 MEST
Affected products: 8.0, 8.1, 8.2, 9.0, 9.1
SUSE Linux Database Server,
SUSE eMail Server III, 3.1
SUSE Linux Enterprise Server 7, 8
SUSE Linux Firewall on CD/Admin host
SUSE Linux Connectivity Server
SUSE Linux Office Server
Vulnerability Type: remote system compromise
Severity (1-10): 5
SUSE default package: yes
Cross References: VU#317350

Content of this advisory:
1) security vulnerability resolved: buffer overflow
problem description, discussion, solution and upgrade information
2) pending vulnerabilities, solutions, workarounds:
– icecast
– sitecopy
– cadaver
– OpenOffice_org
– tripwire
– postgresql
– lha
– mod_proxy
3) standard appendix (further information)
1) problem description, brief discussion, solution, upgrade information

The Dynamic Host Configuration Protocol (DHCP) server is used to
configure clients that dynamically connect to a network (WLAN
hotspots, customer networks, …).
The CERT informed us about a buffer overflow in the logging code of the
server that can be triggered by a malicious client by supplying multiple
hostnames. The hostname strings are concatenated and copied in a
fixed size buffer without checking the buffer bounds.
Other possible buffer overflow conditions exist in using vsprintf()
instead of vsnprintf(). This behavior can be configured during compile-
time. The dhcp/dhcp-server package coming with SUSE LINUX used the
vulnerable vsprintf() function.

Since SuSE Linux 8.1/SuSE Linux Enterprise Server 8 the DHCP server runs
as non-root user in a chroot jail. This setup limits the impact of a
successful attack.

There is no temporary workaround known.

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
the update.
Our maintenance customers are being notified individually. The packages
are being offered to install from the maintenance web.

x86 Platform:

SUSE Linux 9.1:
patch rpm(s):
source rpm(s):

SUSE Linux 9.0:
patch rpm(s):
source rpm(s):

SUSE Linux 8.2:
patch rpm(s):
source rpm(s):

SUSE Linux 8.1:
patch rpm(s):
source rpm(s):

SUSE Linux 8.0:
patch rpm(s):
source rpm(s):

x86-64 Platform:

SUSE Linux 9.1:
patch rpm(s):
source rpm(s):

SUSE Linux 9.0:
patch rpm(s):
source rpm(s):


2) Pending vulnerabilities in SUSE Distributions and Workarounds:

– icecast
The icecast service is vulnerable to a remote denial-of-service
attack. Update packages will be available soon.

– sitecopy
The sitecopy package includes a vulnerable version of the
neon library (CAN-2004-0179, CAN-2004-0398). Update packages will be
available soon.

– cadaver
The cadaver package includes a vulnerable version of the
neon library (CAN-2004-0179, CAN-2004-0398). Update packages will be
available soon.

– OpenOffice_org
The OpenOffice_org package includes a vulnerable version
of the neon library (CAN-2004-0179, CAN-2004-0398). Update packages
will be available soon.

– tripwire
A format string bug in tripwire can be exploited locally
to gain root permissions. Update packages will be available soon.

– postgresql
A buffer overflow in psqlODBC could be exploited to crash the
application using it. E.g. a PHP script that uses ODBC to access a
PostgreSQL database can be utilized to crash the surrounding Apache
web-server. Other parts of PostgreSQL are not affected.
Update packages will be available soon.

– lha
Minor security fix for a buffer overflow while handling command
line options. This buffer overflow could be exploited in conjunction
with other mechanisms to gain higher privileges or access the system
Packages are available now.

– XDM/XFree86
This update resolves random listening to ports by XDM
that allows to connect via the XDMCP. SUSE LINUX 9.1
is affected only.
New packages are currently being tested and will be
available soon.

– mod_proxy
A buffer overflow can be triggered by malicious remote
servers that return a negative Content-Length value.
This vulnerability can be used to execute commands remotely
New packages are currently being tested and will be
available soon.


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 ),
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
list software.
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
to verify the signature of the package, where is the
filename of the rpm package that you have downloaded. Of course,
package authenticity verification can only target an un-installed rpm
package file.
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 “” 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 .


Please enter your comment!
Please enter your name here