SuSE Linux Advisory: pam_smb
Sep 03, 2003, 20:23 (0 Talkback[s])
SuSE Security Announcement
||Wednesday, Sep 3nd 2003 16:40 MEST
||7.2, 7.3, 8.0, 8.1, 8.2
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
||remote privilege escalation
|SuSE default package:
Content of this advisory:
- security vulnerability resolved: buffer overflow problem
description, discussion, solution and upgrade information
- pending vulnerabilities, solutions, workarounds:
- standard appendix (further information)
1) problem description, brief discussion, solution, upgrade
The PAM module (and server) pam_smb allows users of Linux
systems to be authenticated by querying an NT server. Dave Airlie
informed us about a bug in the authentication code of pam_smb that
allows a remote attacker to gain access to a system using pam_smb
by issuing a too long password string.
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.
Intel i386 Platform:
PPC Power PC Platform:
2) Pending vulnerabilities in SuSE Distributions and
- gdm2 Due to a bug in GDM it is possible for local users to read
any text file on a system by creating a symlink from
~/.xsession-errors. Updated packages will be available on our FTP
- whois The client tool whois is vulnerable to several buffer
overflows while processing its command-line arguments. In
conjunction with using untrusted data from remote sources as input,
like using whois in a CGI script and so on, this buffer overflows
may be abused to compromise a system. New whois packages are built
and will be released at the usual locations as soon as quality
assurance is passed.
- node The simple hamradio front-end node is vulnerable to buffer
overflows and format-string bugs. New packages will be available
- postgresql The SQL database server postgresql of version 7.3.x
prior 7.3.4 is vulnerable to buffer overflow attacks. New packages
will be available soon.
- gkrellm The server component of the gkrellm monitoring package
is vulnerable to a buffer overflow. News packages will be available
3) 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 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 email@example.com), 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.
- 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 "firstname.lastname@example.org"
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 <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 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.
||uSE Security Team <firstname.lastname@example.org>
||SuSE Package Signing Key <email@example.com>
Thomas Biege <firstname.lastname@example.org>
... bring the pieces back together, we discover
communication... - Maynard James Keenan