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SUSE Linux Advisory: tcpdump

Jan 14, 2004, 21:56 (0 Talkback[s])

SUSE Security Announcement

Package: tcpdump
Announcement-ID: SuSE-SA:2004:002
Date: Wed Jan 14 14:00:00 MET 2004
Affected products: 8.0, 8.1, 8.2, 9.0
SuSE eMail Server III
SuSE Firewall Adminhost VPN
SuSE Linux Admin-CD for Firewall
SuSE Firewall on CD 2 - VPN
SuSE Firewall on CD 2
SuSE Linux Enterprise Server 7
SLES 8 for IBM iSeries and IBM pSeries
SuSE Linux Enterprise Server 8
SuSE Linux Desktop 1.0
SuSE Linux School Server for i386
SuSE Linux Standard Server 8
SuSE Linux Office Server
UnitedLinux 1.0
Vulnerability Type: remote DoS
Severity (1-10): 3
SUSE default package: yes
Cross References: http://www.tcpdump.org

Content of this advisory:

  1. security vulnerability resolved: remote DoS condition in tcpdumps ISAKMP handling problem description, discussion, solution and upgrade information
  2. pending vulnerabilities, solutions, workarounds:
    • opera
    • mc
    • mod_gzip
    • tripwire
    • cvs
    • gnome-filesystem
    • XDM (XFree86, xf86)
    • inn
    • mpg321
    • popper
    • kdepim3
    • pin
    • 3ddiag
    • mod_auth_shadow
  3. standard appendix (further information)

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

Tcpdump is a well known tool for administrators to analyze network traffic.
There is a bug in the tcpdump code responsible for handling ISAKMP messages. This bug allows remote attackers to destroy a current tcpdump session by tricking the tcpdump program with evil ISAKMP messages to enter an endless loop.

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.

i386 Intel Platform:

ftp://ftp.suse.com/pub/suse/i386/update/9.0/rpm/i586/tcpdump-3.7.2-72.i586.rpm a4395d7d819ea8918778f9a3b91c297c
patch rpm(s):
ftp://ftp.suse.com/pub/suse/i386/update/9.0/rpm/i586/tcpdump-3.7.2-72.i586.patch.rpm 4eae84a6074af7c2386f9145a49f9477
source rpm(s):
ftp://ftp.suse.com/pub/suse/i386/update/9.0/rpm/src/tcpdump-3.7.2-72.src.rpm b32b0e08e9add34b3c42599734723454

ftp://ftp.suse.com/pub/suse/i386/update/8.2/rpm/i586/tcpdump-3.7.1-341.i586.rpm 39c8e448e4056111444658ce93281ca3
patch rpm(s):
ftp://ftp.suse.com/pub/suse/i386/update/8.2/rpm/i586/tcpdump-3.7.1-341.i586.patch.rpm dfcb12acdad084fcf15508361a3018b5
source rpm(s):
ftp://ftp.suse.com/pub/suse/i386/update/8.2/rpm/src/tcpdump-3.7.1-341.src.rpm b92c579649acc9fb19810bcc7a670d6d

ftp://ftp.suse.com/pub/suse/i386/update/8.1/rpm/i586/tcpdump-3.7.1-341.i586.rpm 5527a4823b041894324ae65b02e40011
patch rpm(s):
ftp://ftp.suse.com/pub/suse/i386/update/8.1/rpm/i586/tcpdump-3.7.1-341.i586.patch.rpm f4c933fd520dbcab98092e5a2fe8846c
source rpm(s):
ftp://ftp.suse.com/pub/suse/i386/update/8.1/rpm/src/tcpdump-3.7.1-341.src.rpm 0b118d8fe78cea0cc2405a934a77b7fd

ftp://ftp.suse.com/pub/suse/i386/update/8.0/n1/tcpdump-3.6.2-330.i386.rpm d77a4e84796cc96be12c97ea19d272bb
patch rpm(s):
ftp://ftp.suse.com/pub/suse/i386/update/8.0/n1/tcpdump-3.6.2-330.i386.patch.rpm 74882ed085cc27c938ed5529df8040c4
source rpm(s):
ftp://ftp.suse.com/pub/suse/i386/update/8.0/zq1/tcpdump-3.6.2-330.src.rpm 51f39911dadd7add63e07a922840314c

Opteron x86_64 Platform:

ftp://ftp.suse.com/pub/suse/x86_64/update/9.0/rpm/x86_64/tcpdump-3.7.2-68.x86_64.rpm 0278d04abfe2bcffca8f45e711beebd0
patch rpm(s):
ftp://ftp.suse.com/pub/suse/x86_64/update/9.0/rpm/x86_64/tcpdump-3.7.2-68.x86_64.patch.rpm 348b217551a35a6e4f9698e92f3170c8
source rpm(s):
ftp://ftp.suse.com/pub/suse/x86_64/update/9.0/rpm/src/tcpdump-3.7.2-68.src.rpm 2deb0ae848d115e00593a5639ec5b6b8

2) Pending vulnerabilities in SUSE Distributions and Workarounds:

  • Opera web browser The SuSE Security Team has discovered a flaw in the Opera web browsers X.509 certificate handling during the SSL handshake. It allows attackers to prompt the Opera web browser with invalid certificates containing the public key of the attacker. Thus, he can read or modify the HTTPS traffic without notification by the user. New packages fixing this problem will be available soon on our ftp servers.
  • 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 will be released soon.
  • mod_gzip (apache-contrib) 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. After more testing a new apache-contrib RPM package will be released.
  • 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. Additionally the package will include a fix for a format-string bug. New packages will be available soon.
  • gnome-filesystem A script included in the gnome-filesystem package handles temporary files insecurely. This script is called by YaST2 with root privileges. The bug can be exploited locally to create or overwrite arbitrary files in the filesystem. The bug is fixed in our current source-tree since November 2003 but nevertheless update packages for older SuSE Linux versions will be released soon.
  • XDM (XFree86, xf86) A missing check for failure conditions in the PAM code of XDM can lead to local root access in conjunction with Kerberos and alike. New packages will be released soon.
  • inn A buffer overflow in the code for handling control messages can be exploited remotely. New packages are available on our FTP servers.
  • mpg321 A format-bug in mpg321 can be exploited (even remotely by HTTP streaming) to execute code with the permissions of the user running mpg321 on special MP3 files. New packages are available on our FTP servers.
  • popper Popper handles temporary files in an insecure manner. New packages are available on our FTP servers.
  • kdepim3 It was possible to use a buffer overflow via a special crafted vcard file to run code during generating previews. By default it was only possible on local filesystems, but the user can enable this also for remote file systems. New packages are available on our FTP servers.
  • pin Pin handles local temporary files in an insecure manner which may lead to local privilege escalation. Thanks to Stefan Nordhausen <nordhaus at informatik.hu-berlin.de/> for reporting one of the issues. New packages are available on our FTP servers.
  • 3ddiag Some 3ddiag scripts handle temporary files in an insecure manner. Thanks to Stefan Nordhausen <nordhaus at informatik.hu-berlin.de/> for reporting some of the issues. New packages will be available on our FTP servers soon.
  • mod_auth_shadow (apache-contrib) This apache module ignores account expiration dates. The update will be released together with mod_gzip.

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'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.

Type Bits/KeyID Date User ID
pub 2048R/3D25D3D9 1999-03-06 SuSE Security Team <security@suse.de>
pub 1024D/9C800ACA 2000-10-19 SuSE Package Signing Key <build@suse.de>