SuSE Linux Advisory: glibc
May 27, 2003, 18:59 (0 Talkback[s])
SuSE Security Announcement
||Monday, May 26th 2003 16:12 MET
||7.1, 7.2, 7.3, 8.0, 8.1, SuSE Linux Database Server, SuSE eMail
Server III, 3.1 SuSE Linux Enterprise Server 7, SuSE Linux Firewall
on CD/Admin host SuSE Linux Connectivity Server SuSE Linux Office
||remote system compromise
|SuSE default package:
Content of this advisory:
- security vulnerability resolved: integer overflow in XDR code
problem description, discussion, solution and upgrade
- pending vulnerabilities, solutions, workarounds:
- standard appendix (further information)
- problem description, brief discussion, solution, upgrade
Another integer overflow was found in glibc' XDR code. This bug
is equal to the one described in advisory SuSE-SA:2002:031. The
overflow occurs in the function xdrmem_getbytes() and can be used
by external attackers to execute arbitrary code.
There is no temporary workaround for this security problem other
than disabling all RPC based server and client programs. The
permanent solution is to update the glibc packages with the update
packages listed below.
Notes, Special installation instructions:
The shared libraries that were installed on the system before
the update have been removed from the filesystem, but they are
still in use by the running applications. Therefore, the disk-space
as well as the memory will not be freed until the last process that
uses these files exits. We recommend to reboot the system to
workaround this problem.
Listed below you find the URLs for the update packages for the
SuSE Linux products. We only list the packages that are relevant
for the security update. Our maintenance customers are being
notified individually. The packages are being offered to install
from the maintenance web.
Intel i386 Platform:
AXP Alpha Platform:
PPC Power PC Platform:
- Pending vulnerabilities in SuSE Distributions and
Several one-byte buffer overflows and integer overflows are fixed.
These bugs lead to remote denial-of-service or even remote code
execution. New packages are available on our FTP servers.
A buffer overflow in the Xlib code can be triggered while handling
the environment variable XLOCALEDIR. The X version affected is
4.2.0 (SuSE Linux 8.0 and 8.1). New packages are available on our
VNC (Virtual Network Computing) uses a weak cookie generation
process which can be exploited by an attacker to bypass
authentication. New packages are available on our FTP servers.
Several buffer overflows got fixed that can be exploited remotely
by a malicious IRC servers. New packages are available on our FTP
lv reads config files from the current directory without verifying
the ownership. If lv is called in world-writeable directories like
/tmp it can be tricked into executing commands by putting a
malicious config file there. New packages are available on our FTP
- standard appendix: authenticity verification, additional
- 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:
- md5sums as provided in the (cryptographically signed)
- using the internal gpg signatures of the rpm package.
- execute the command
after you downloaded the file from a SuSE ftp server or its
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 firstname.lastname@example.org), 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
- 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. Prerequisites:
- gpg is installed
- 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 "email@example.com"
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 subscribe:
For general information or the frequently asked questions (faq)
send mail to:
SuSE's security contact is <firstname.lastname@example.org
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.
||SuSE Security Team <email@example.com>
||SuSE Package Signing Key <firstname.lastname@example.org>
Thomas Biege <email@example.com>
SuSE Linux AG,Deutschherrnstr. 15-19,90429 Nuernberg Function:
Security Support & Auditing "lynx -source http://www.suse.de/~thomas/contact/thomas.asc
| gpg --import" Key fingerprint = 7254 B15D B3C4 943F 485E 0BBD
8ECC D7CB C200 A213
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