SUSE Linux Advisory: lftp

SUSE Security Announcement

Content of this advisory:

1. security vulnerability resolved:
   • local buffer overflow problem description, discussion, solution
     and upgrade information
2. pending vulnerabilities, solutions, workarounds:
   • mc
   • mod_gzip
   • freeradius
   • tripwire
   • cvs
   • irssi
   • atftp
3. standard appendix (further information)

1) problem description, brief discussion, solution, upgrade
information

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:

SuSE-9.0:

ftp://ftp.suse.com/pub/suse/i386/update/9.0/rpm/i586/lftp-2.6.6-71.i586.rpm
2e5aee46868b5b19c26a8559927e8663
patch rpm(s):

ftp://ftp.suse.com/pub/suse/i386/update/9.0/rpm/i586/lftp-2.6.6-71.i586.patch.rpm
0468cf8f2b2b4c18a854f51ef63470b7
source rpm(s):

ftp://ftp.suse.com/pub/suse/i386/update/9.0/rpm/src/lftp-2.6.6-71.src.rpm
a32eee3ff4eeb322d44f04b9f8ff4c9c

SuSE-8.2:

ftp://ftp.suse.com/pub/suse/i386/update/8.2/rpm/i586/lftp-2.6.4-44.i586.rpm
df0d7c059cd3bb4fe47c927849fd9a5e
patch rpm(s):

ftp://ftp.suse.com/pub/suse/i386/update/8.2/rpm/i586/lftp-2.6.4-44.i586.patch.rpm
eb9d6aedc25d3e2d25b63999526ee1bd
source rpm(s):

ftp://ftp.suse.com/pub/suse/i386/update/8.2/rpm/src/lftp-2.6.4-44.src.rpm
63695b02bf520b02f93ec73078d6e4d8

2) Pending vulnerabilities in SUSE Distributions and
Workarounds:

• mc
  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.
• mod_gzip
  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
  bugs.
• freeradius
  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
  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.
• cvs
  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.
• irssi
  Under special circumstances the the irc-client irssi can be crashed
  remotely by other irc-clients. A fix will be available soon.
• atftp
  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
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.
  3. 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.
  4. 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:
     1. gpg is installed
     2. 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
        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:

  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
  announcements 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> or
<security@suse.de>. The
<security@suse.de>
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.

Bye,

Thomas
—
Thomas Biege <thomas@suse.de>, SUSE LINUX AG,
Security Support & Auditing