SUSE Linux Advisory: lftp
Dec 15, 2003, 16:56 (0 Talkback[s])
SUSE Security Announcement
||Monday, Dec 15th 2003 14:30 MET
||8.2, 9.0 remote system compromise
|SUSE default package:
Content of this advisory:
- security vulnerability resolved:
- local 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 the flexible and powerful FTP command-line client lftp is
vulnerable to two remote buffer overflows.
When using lftp via HTTP or HTTPS to execute commands like 'ls' or
'rels' specially prepared directories on the server can trigger a
buffer overflow in the HTTP handling functions of lftp to possibly
execute arbitrary code on the client-side.
Please note, to exploit these bugs an attacker has to control the
serverside of the context and the attacker will only gain access to
the account of the user that is executing lftp.
There is no temporary 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, 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:
2) Pending vulnerabilities in SUSE Distributions and
By using a special combination of links in archive-files it is
possible to execute arbitrary commands while mc tries to open it in
its VFS. The packages are currently tested and will be release as
soon as possible.
The apache module mod_gzip is vulnerable to remote code execution
while running in debug-mode. We do not ship this module in
debug-mode but future versions will include the fix. Additionally
the mod_gzip code was audited to fix more possible security related
Two vulnerabilities were found in the FreeRADIUS package. The
remote denial-of-service attack bug was fixed and new packages will
be released as soon as testing was successfully finished. The other
bug is a remote buffer overflow in the module rlm_smb. We do not
ship this module and will fix it for future releases.
Tripwire is a file integrity checker. The tripwire version on SuSE
Linux 8.2 and 9.0 do crash when a requested file does not exists.
New packages will be available soon.
The cvs server-side can be tricked to create files in the root
filesystem of the server by requesting malformed modules. The
permissions on the root filesystem normally prevent this
malfunction. New packages will be available soon.
Under special circumstances the the irc-client irssi can be crashed
remotely by other irc-clients. A fix will be available soon.
A buffer overflow vulnerability discovered by Rick Patel has been
fixed in the atftpd (trivial file transfer protocol, UDP oriented)
daemon, contained in the atftp package. Update packages for the
affected SUSE Linux distributions 8.1 and 8.2 have been published
on our ftp server today. We explicitly thank Dirk Mueller, KDE
developer, for notifying SUSE Security about the pending treatment
of this incident.
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 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 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 "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:
- 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
announcements 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
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,
Security Support & Auditing