SuSE Security Announcement: samba
Jun 29, 2001, 14:15 (0 Talkback[s])
Date: Fri, 29 Jun 2001 14:56:36 +0200 (MEST)
From: Roman Drahtmueller <firstname.lastname@example.org>
Subject: [suse-security-announce] SuSE Security Announcement: samba (SuSE-SA:2001:021)
SuSE Security Announcement
Date: Friday, Jun 29th 2001 14:45 MEST
Affected SuSE versions: (6.0, 6.1, 6.2) 6.3, 6.4, 7.0, 7.1, 7.2
Vulnerability Type: possible remote root compromise
Severity (1-10): 7
SuSE default package: yes
Other affected systems: systems using samba and the %m macro in the
samba main config file
Content of this advisory:
1) security vulnerability resolved: samba
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
Michal Zalewski discovered that a remote attacker can write to files
owned by root if the samba config file /etc/smb.conf contains the %m
macro to specify the logfile for logging access to the samba server.
The %m macro substitutes the NetBIOS name - improper validation of
this name allows an attacker to write to any file in the system.
SuSE Linux distributions do not ship a default /etc/smb.conf config
file that contains the %m macro. Therefore, SuSE distributions are not
vulnerable to the bug in the out-of-the-box state.
In addition to the remotely exploitable bug, there exists another
vulnerability which is fixed with the update packages we provide
below: temporary files are being handled insecurely so that an
attacker with local access to the system can increase her privileges.
This error was discovered by Marcus Meissner, Caldera. This specific
problem has been fixed with the release of the samba-2.0.9 version.
samba release version 2.0.8 intended to correct this local problem, but
due to an error, 2.0.9 contained the complete fix.
Only the 2.0.10 version as offered for the SuSE Linux distributions
6.3, 6.4, 7.0 and 7.1 fixes all known problems in the samba package.
For the recently released SuSE-7.2 distribution we provide an update
package to the version 2.2.0a.
We thank Martin Walter, CC university of Freiburg, for his helpful
contribution in debugging the Large File Support (LSF) of the 7.1
* We have removed the samba packages from the update trees for the 6.0,
6.1 and 6.2 distributions on our ftp-server. These packages would
introduce security risks if installed on a host.
* The samba source rpm package in distributions after and including 7.0
generates both the samba.rpm and the smbclnt.rpm package. It is
recommended to update both packages for these distributions.
Please download the update package from locations described below and
check the authenticity of the rpm package file using a method as
described in section 3 of this security announcement.
Use the command 'rpm -Uhv file.rpm' to apply the update.
Special installation instructions:
After successful installation of the update package, it is necessary to
restart the samba server. To do this, use the following command
i386 Intel Platform:
AXP Alpha Platform:
PPC Power PC Platform:
2) Pending vulnerabilities in SuSE Distributions and Workarounds:
- Location of update packages on ftp.suse.de/ftp.suse.com:
Licensing problems as well as US crypto-software export regulations
keep us from publishing update packages that contain cryptographical
software on ftp ftp.suse.com, our US ftp server. Bandwith requirements
keep us from moving the server to our German location. For these
reasons, crypto-packages for SuSE Linux distributions before SuSE-7.1
can be obtained from the equivalent tree on ftp.suse.de/. Distributions
after and including SuSE-7.1 have their crypto-packages hosted on
ftp.suse.com/. This was possible with some efforts to remove all non-free
cryptographical algorithms from our packages.
In our last security announcement (SuSE-SA:2001:020 gpg/gnupg) we
announced that we investigate the buffer overflow that has been found
in qpopper versions before 4.0.3. SuSE Linux distributions are not
affected by this bug because a different version is being used.
email@example.com has found an exploitable buffer overflow bug in
the dsh program from the dqs package on SuSE Linux distributions.
To workaround the problem, do "chmod -s /usr/bin/dsh" and change the
files /etc/permissions* to reflect the change. If you do not need the
dqs package, then deinstall it (rpm -e dqs).
Packages for most of the supported SuSE Linux distributions are
available at the usual location ftp://ftp.suse.com/pub/suse//
for download and installation/update. Do not forget to change the files
/etc/permissions* to remove the suid-bit from the dsh program. Please
note that we will not issue a dedicated security announcement for this
Paul Starzetz discovered a security weakness in the setuid root program
/usr/share/pcp/bin/pmpost. The common library in pcp trusts the
environment that has been supplied by the user, regardless of privileged
execution or not. By consequence, a user can specify the configuration
file and therefore write to files owned by root. The problem is not based
on insecurely following symlinks as stated by Paul Starzetz.
The pcp package is not installed by default in SuSE Linux distributions.
We have provided update packages for the SuSE Linux distributions version
7.1 and 7.2 that remove the setuid bit from the pmpost binary. Versions
before SuSE-7.1 were not affected because the setuid bit was not set.
We thank Keith Owens and Mark Goodwin from Silicon Graphics for responding
quickly and for publishing a new version of the pcp package which will
be included in future releases of the SuSE Linux distribution. For more
information see the /usr/share/doc/packages/pcp directory of your SuSE
Linux installation after installing the update package, or go to
obtained from http://oss.sgi.com/projects/pcp/download .
Please note that there will not be a dedicated security announcement
for this specific bug.
A buffer overflow has been found in xinetd, all versions, all
SuSE Linux distributions. It may be abused to remotely attack a host
running xinetd. The xinetd package is not installed by default in SuSE
Linux distributions. Manual interaction must have been applied to run
Update packages can be found at the usual location on our ftp server.
The security announcement for this security problem is underway.
- fetchmail (fetchml)
New fetchmail packages are available on the ftp server. The packages
cure a buffer overflow that can be exploited by sending a victim a
specially designed email, waiting for the victim's fetchmail program
to pick up the email. We are preparing a security announcement for this
update packages for the openssh package after (and including) SuSE-6.4
are available on our ftp servers ftp ftp.suse.de (for < 7.1) or
ftp ftp.suse.com (for >= 7.1). We are currently checking for a non-security
related irregularity in sshd's behaviour under faulty setup conditions.
SuSE Linux distributions do not contain the exim Mail Transport Agent
(See http://www.exim.org/ for details) and are therefore not susceptible
to the recently found security-related bugs.
SuSE Linux distributions do not contain the webmin administration
web frontend (See http://www.webmin.org/ for details) and are therefore
not vulnerable to the recently found security-related problems in the
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 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
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 is the
filename of the rpm package that you have downloaded. Of course,
package authenticity verification can only target an uninstalled 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 "email@example.com" upon installation or upgrade, provided that
the package gpg is installed. The file containing the public key
is placed at the toplevel 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 annoucements 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 <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 cleartext signature shows proof of the
authenticity of the text.
SuSE GmbH makes no warranties of any kind whatsoever with respect
to the information contained in this security advisory.