SUSE Security Announcement: Linux Kernel
Posted on: 04/14/2004 01:05 PM

SUSE has released a kernel update


SUSE Security Announcement

Package: Linux Kernel
Announcement-ID: SuSE-SA:2004:009
Date: Wednesday, Apr. 14th 2004 16:00 MEST
Affected products: 8.0, 8.1, 8.2, 9.0
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: - local privilege escalation
- information leakage
Severity (1-10): 6
SUSE default package: yes
Cross References: CAN-2004-0109

Content of this advisory:
1) security vulnerability resolved:
- buffer overflow in ISO9660 code
- information leakage in JFS
problem description, discussion, solution and upgrade information
2) pending vulnerabilities, solutions, workarounds:
- mailman
- sysstat
- neon
- openssh
- kdeprint/kdelibs3
- MPlayer
- sysstat
- apache2
- emil
- metamail
- tcpdump
3) standard appendix (further information)


1) problem description, brief discussion, solution, upgrade information

iDEFENSE Inc. informed us about a buffer overflow in the linux 2.4
kernel code which handles ISO9660 filesystems. The original code is not
able to handle very long symlink names.
The vulnerability can be triggered locally by mounting removable media
that contains a malformed filesystem or by using the loopback device.
Exploiting this buffer overflow results in kernel-level access to the

Another vulnerability allows the retrieval of private informations
from JFS filesystems due to the lack of cleaning up (writing zeros)
used sectors on the harddrive. This bug needs root privilges to be

The following paragraphs will guide you through the installation
process in a step-by-step fashion. The character sequence "****"
marks the beginning of a new paragraph. In some cases, you decide
if the paragraph is needed for you or not. Please read through all
of the steps down to the end. All of the commands that need to be
executed are required to be run as the superuser (root). Each step
relies on the steps before to complete successfully.

**** Step 1: Determine the needed kernel type

Please use the following command to find the kernel type that is
installed on your system:

rpm -qf /boot/vmlinuz

The following options are possible (disregarding the version and build
number following the name, separated by the "-" character):

k_deflt # default kernel, good for most systems.
k_i386 # kernel for older processors and chipsets
k_athlon # kernel made specifically for AMD Athlon(tm) family processors
k_psmp # kernel for Pentium-I dual processor systems
k_smp # kernel for SMP systems (Pentium-II and above)
k_smp4G # kernel for SMP systems which supports a maximum of 4G of RAM

**** Step 2: Download the package for your system

Please download the kernel RPM package for your distribution with the
name starting as indicated by Step 1. The list of all kernel rpm
packages is appended below. Note: The kernel-source package does not
contain any binary kernel in bootable form. Instead, it contains the
sources that the binary kernel rpm packages are made from. It can be
used by administrators who have decided to build their own kernel.
Since the kernel-source.rpm is an installable (compiled) package that
contains sources for the linux kernel, it is not the source RPM for
the kernel RPM binary packages.

The kernel RPM binary packages for the distributions can be found at these
locations below


After downloading the kernel RPM package for your system, you should
verify the authenticity of the kernel rpm package using the methods as
listed in section 3) of each SUSE Security Announcement.

**** Step 3: Installing your kernel rpm package

Install the rpm package that you have downloaded in Steps 3 or 4 with
the command
rpm -Uhv --nodeps --force <K_FILE.RPM>
where <K_FILE.RPM> is the name of the rpm package that you downloaded.

Warning: After performing this step, your system will likely not be
able to boot if the following steps have not been fully

If you run SUSE LINUX 8.1 and haven't applied the previous
kernel update (SUSE-SA:2003:034), AND use the freeswan package,
you also need to update the freeswan rpm as a dependency as offered
by YOU (YaST Online Update). The package can be downloaded from

**** Step 4: configuring and creating the initrd

The initrd is a ramdisk that is being loaded into the memory of your
system together with the kernel boot image by the bootloader. The
kernel uses the content of this ramdisk to execute commands that must
be run before the kernel can mount its actual root filesystem. It is
usually used to initialize SCSI drivers or NIC drivers for diskless

The variable INITRD_MODULES in /etc/sysconfig/kernel determines
which kernel modules will be loaded in the initrd before the kernel
has mounted its actual root filesystem. The variable should contain
your SCSI adapter (if any) or filesystem driver modules.

With the installation of the new kernel, the initrd has to be
re-packed with the update kernel modules. Please run the command


as root to create a new init ramdisk (initrd) for your system.
On SuSE Linux 8.1 and later, this is done automatically when the
RPM is installed.

**** Step 5: bootloader

If you run a SUSE LINUX 8.x or a SLES8 system, there are two options:
Depending on your software configuration, you have the lilo bootloader
or the grub bootloader installed and initialized on your system.
The grub bootloader does not require any further actions to be
performed after the new kernel images have been moved in place by the
rpm Update command.
If you have a lilo bootloader installed and initialized, then the lilo
program must be run as root. Use the command

grep LOADER_TYPE /etc/sysconfig/bootloader

to find out which boot loader is configured. If it is lilo, then you
must run the lilo command as root. If grub is listed, then your system
does not require any bootloader initialization.

Warning: An improperly installed bootloader may render your system

**** Step 6: reboot

If all of the steps above have been successfully applied to your
system, then the new kernel including the kernel modules and the
initrd should be ready to boot. The system needs to be rebooted for
the changes to become active. Please make sure that all steps are
complete, then reboot using the command
shutdown -r now
init 6

Your system should now shut down and reboot with the new kernel.

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

There is no 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, to apply the update use the command "rpm -Fhv file.rpm".
Our maintenance customers are being notified individually. The packages
are being offered to install from the maintenance web.

Intel i386 Platform:

source rpm(s):

source rpm(s):

source rpm(s):

source rpm(s):


2) Pending vulnerabilities in SUSE Distributions and Workarounds:

- mailman
A remote denial-of-service attack can be triggered in mailman 2.0.x
New packages are available on our FTP servers.

- sysstat
Two cases of insecure temporary file handling were found.
New packages are available on our FTP servers.

- neon
The neon package contained various format string vulnerabilities
which have been fixed. New packages are available on our FTP servers.
Maintained products do not contain the neon package and are therefore
not affected. (CAN-2004-0179)

- openssh
The scp program which is part of the openssh package allowed evil
servers to trick clients into creating arbitrary files with
permissions of the user invoking scp. New packages are available on
our FTP servers.

- kdeprint/kdelibs3
The kdeprint system called the ghostscript program without the -dSAFER
option. This has been fixed. New packages are available on our FTP
servers. The package is named "kdelibs3". Maintained products are
not affected.

- MPlayer
The mplayer program contained a buffer overflow while escaping
large URLs. This has been fixed. New MPlayer packages are currently
being tested and will be available soon on our FTP servers.

- sysstat
This update close two cases of insecure temporary file handling in
the isag code.
New packages are available on our FTP servers.

- apache2
This update fixes a memory leak in the mod_ssl module of apache2
(CAN-2004-0113), a possible remote DoS attack on accessing rarely
used listening ports (CAN-2004-0174), and a problem with unescaped
special characters in log files that could present a security hazard
for terminal emulators (CAN-2003-0020).
New packages are available on our FTP servers.

- emil
The emil mail filter contains buffer overflows and format-string
bugs that can be exploited remotely if emil is used in conjunction
with procmail, sendmail and alike. (CAN-2004-0152, CAN-2004-0153)
New packages are available on our FTP servers

- metamail
This update fixes two buffer overflows and two format string bugs
that can be exploited remotely in conjunction with other tools
to gain access to a system with the privileges of the user running
New packages will be available soon.

- tcpdump
The tcpdump program contains a remotely exploitable denial of service
condition in its ISAKMP packet handling. New tcpdump packages are
currently being tested and 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
md5sum <name-of-the-file.rpm>
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 <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
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 .

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