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 <draht@suse.de>
Subject: [suse-security-announce] SuSE Security Announcement: samba (SuSE-SA:2001:021)
____________________________________________________________________________
SuSE Security Announcement
Package: samba
Announcement-ID: SuSE-SA:2001:021
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
package.
NOTES:
* 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
rcsmb restart
as root.
i386 Intel Platform:
SuSE-7.2
ftp://ftp.suse.com/pub/suse/i386/update/7.2/n2/samba-2.2.0a-0.i386.rpm
d0cab6f5d34645dc9e41f2ae0aed8a30
ftp://ftp.suse.com/pub/suse/i386/update/7.2/n1/smbclnt-2.2.0a-0.i386.rpm
aba5da72a8175c2119e82d01184dd320
source rpm:
ftp://ftp.suse.com/pub/suse/i386/update/7.2/zq1/samba-2.2.0a-0.src.rpm
243964fad8bda61039020acf7a13858f
SuSE-7.1
ftp://ftp.suse.com/pub/suse/i386/update/7.1/n2/samba-2.0.10-0.i386.rpm
da1232db9259196a58e7e3b46065e8c8
ftp://ftp.suse.com/pub/suse/i386/update/7.1/n1/smbclnt-2.0.10-0.i386.rpm
a497089893fd375986ab5a031eddaf05
source rpm:
ftp://ftp.suse.com/pub/suse/i386/update/7.1/zq1/samba-2.0.10-0.src.rpm
07705a9cacb7f9f28b434a1e6a6fe3bb
SuSE-7.0
ftp://ftp.suse.com/pub/suse/i386/update/7.0/n1/samba-2.0.10-0.i386.rpm
a20a0241fad9b3381758946e9f9ae16d
ftp://ftp.suse.com/pub/suse/i386/update/7.0/n1/smbclnt-2.0.10-0.i386.rpm
c0194e29ff9f6ae5da8500f6a6250bab
source rpm:
ftp://ftp.suse.com/pub/suse/i386/update/7.0/zq1/samba-2.0.10-0.src.rpm
e412b83bbf653023cadbf163a3ec296f
SuSE-6.4
ftp://ftp.suse.com/pub/suse/i386/update/6.4/n1/samba-2.0.10-0.i386.rpm
e740834c08f1a91efed8abfe1ffd1fd1
source rpm:
ftp://ftp.suse.com/pub/suse/i386/update/6.4/zq1/samba-2.0.10-0.src.rpm
ed22708ec5fbc14cfdfc0cd45b3033e0
SuSE-6.3
ftp://ftp.suse.com/pub/suse/i386/update/6.3/n1/samba-2.0.10-0.i386.rpm
da6aeaf7043bc03199e4c1d5c04d3be6
source rpm:
ftp://ftp.suse.com/pub/suse/i386/update/6.3/zq1/samba-2.0.10-0.src.rpm
84e325fc575143a576c42f386c88e44c
Sparc Platform:
SuSE-7.1
ftp://ftp.suse.com/pub/suse/sparc/update/7.1/n2/samba-2.0.10-0.sparc.rpm
5b702a797836de3352c96b0b33297d13
ftp://ftp.suse.com/pub/suse/sparc/update/7.1/n1/smbclnt-2.0.10-0.sparc.rpm
00c29e2ff26d00b60a81e095a78623c7
source rpm:
ftp://ftp.suse.com/pub/suse/sparc/update/7.1/zq1/samba-2.0.10-0.src.rpm
1d9d41cfeab79ef851cb4666a0259731
SuSE-7.0
ftp://ftp.suse.com/pub/suse/sparc/update/7.0/n1/samba-2.0.10-0.sparc.rpm
48ef896322723e4247b13db719a6d593
ftp://ftp.suse.com/pub/suse/sparc/update/7.0/n1/smbclnt-2.0.10-0.sparc.rpm
fdacfbe34e46919515dc54d288b6e56a
source rpm:
ftp://ftp.suse.com/pub/suse/sparc/update/7.0/zq1/samba-2.0.10-0.src.rpm
b023db5df4e6b26ed8263d61de3c9915
AXP Alpha Platform:
SuSE-7.1
ftp://ftp.suse.com/pub/suse/axp/update/7.1/n2/samba-2.0.10-0.alpha.rpm
3302ca10f2e779ff168d44bc4280158a
ftp://ftp.suse.com/pub/suse/axp/update/7.1/n1/smbclnt-2.0.10-0.alpha.rpm
440ff9a0fefb54ac85977e4598e39eed
source rpm:
ftp://ftp.suse.com/pub/suse/axp/update/7.1/zq1/samba-2.0.10-0.src.rpm
49f109c06957f200cd5112dc872273fc
SuSE-7.0
ftp://ftp.suse.com/pub/suse/axp/update/7.0/n1/samba-2.0.10-0.alpha.rpm
6e68f4d9156238874755bd9bac59d713
ftp://ftp.suse.com/pub/suse/axp/update/7.0/n1/smbclnt-2.0.10-0.alpha.rpm
c1935910e75c956ed8b2ce9e4c324d55
source rpm:
ftp://ftp.suse.com/pub/suse/axp/update/7.0/zq1/samba-2.0.10-0.src.rpm
210dde7e938ff7d1d303e80a13d11673
SuSE-6.4
ftp://ftp.suse.com/pub/suse/axp/update/6.4/n1/samba-2.0.10-0.alpha.rpm
9d6cf089b447ba4aefe1d70cf2771a22
source rpm:
ftp://ftp.suse.com/pub/suse/axp/update/6.4/zq1/samba-2.0.10-0.src.rpm
377b183857e179772481840caffd7db4
SuSE-6.3
ftp://ftp.suse.com/pub/suse/axp/update/6.3/n1/samba-2.0.10-0.alpha.rpm
e4871d1a0423bec9999fde9a9b85ab23
source rpm:
ftp://ftp.suse.com/pub/suse/axp/update/6.3/zq1/samba-2.0.10-0.src.rpm
51cf42a086a4a26619323311660dbfb8
PPC Power PC Platform:
SuSE-7.1
ftp://ftp.suse.com/pub/suse/ppc/update/7.1/n2/samba-2.0.10-0.ppc.rpm
dfaa395540e2e01b3ccc7177f0f297c4
ftp://ftp.suse.com/pub/suse/ppc/update/7.1/n1/smbclnt-2.0.10-0.ppc.rpm
ca9059bfbafe4553ae6bc79dad70ce31
source rpm:
ftp://ftp.suse.com/pub/suse/ppc/update/7.1/zq1/samba-2.0.10-0.src.rpm
df603b78073673c7f8988639b1cb2c1e
SuSE-7.0
ftp://ftp.suse.com/pub/suse/ppc/update/7.0/n1/samba-2.0.10-0.ppc.rpm
65b2d0e71902afb4f3cafa67f2d5c628
ftp://ftp.suse.com/pub/suse/ppc/update/7.0/n1/smbclnt-2.0.10-0.ppc.rpm
a1de2eb26df810831f65af2feb0f12f9
source rpm:
ftp://ftp.suse.com/pub/suse/ppc/update/7.0/zq1/samba-2.0.10-0.src.rpm
17777fa091391825ebd9d90018f950bf
SuSE-6.4
ftp://ftp.suse.com/pub/suse/ppc/update/6.4/n1/samba-2.0.10-0.ppc.rpm
4e44aaab59f3c624e77b83bbbc05bb18
source rpm:
ftp://ftp.suse.com/pub/suse/ppc/update/6.4/zq1/samba-2.0.10-0.src.rpm
5893c01a4f1ddf8f8d2e77ac8ee785e9
____________________________________________________________________________
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.
- qpopper
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.
- dqs
dex@raza-mexicana.org 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
specific bug.
- pcp
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.
- xinetd
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
the daemon.
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
problem.
- openssh
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.
- exim
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.
- webmin
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
software.
____________________________________________________________________________
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 security@suse.de),
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 is the
filename of the rpm package that you have downloaded. Of course,
package authenticity verification can only target an uninstalled rpm
package file.
Prerequisites:
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 "build@suse.de" 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
subscribe:
suse-security@suse.com
- general/linux/SuSE security discussion.
All SuSE security announcements are sent to this list.
To subscribe, send an email to
<suse-security-subscribe@suse.com>
suse-security-announce@suse.com
- SuSE's announce-only mailing list.
Only SuSE's security annoucements are sent to this list.
To subscribe, send an email to
<suse-security-announce-subscribe@suse.com>
For general information or the frequently asked questions (faq)
send mail to:
<suse-security-info@suse.com> or
<suse-security-faq@suse.com> respectively.
===================================================
SuSE's security contact is <security@suse.com>.
The <security@suse.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.
