TCPDump / LIBPCap Trojan Horse Vulnerability
Risk
High
Date Discovered
11-13-2002
Description
It has been announced that the server hosting tcpdump and libpcap, www.tcpdump.org, was compromised recently. It has been reported that the intruder made modifications to the source code of tcpdump and libpcap to include trojan horse code. Downloads of the source code of tcpdump and libpcap from www.tcpdump.org, and numerous mirrors, likely contain the trojan code.
Reports say that the trojan will run once upon compilation of tcpdump or libpcap. Once the trojan is executed, it attempts to connect to host 212.146.0.34 on port 1963.
The MD5 sums of the trojaned versions are reported to be:
MD5 Sum 73ba7af963aff7c9e23fa1308a793dca libpcap-0.7.1.tar.gz
MD5 Sum 3a1c2dd3471486f9c7df87029bf2f1e9 tcpdump-3.6.2.tar.gz
MD5 Sum 3c410d8434e63fb3931fe77328e4dd88 tcpdump-3.7.1.tar.gz
The MD5 sums of the non-trojaned versions are:
MD5 Sum 0597c23e3496a5c108097b2a0f1bd0c7 libpcap-0.7.1.tar.gz
MD5 Sum 6bc8da35f9eed4e675bfdf04ce312248 tcpdump-3.6.2.tar.gz
MD5 Sum 03e5eac68c65b7e6ce8da03b0b0b225e tcpdump-3.7.1.tar.gz
The non-trojaned versions of these tools are available at the following locations:
http://www.ibiblio.org/pub/Linux/distributions/gentoo/distfiles/libpcap-0.7.1.tar.gz
http://www.ibiblio.org/pub/Linux/distributions/gentoo/distfiles/tcpdump-3.6.2.tar.gz
http://www.ibiblio.org/pub/Linux/distributions/gentoo/distfiles/tcpdump-3.7.1.tar.gz
Additionally, the trojan displays similarity to those found in irssi, fragroute, fragrouter, BitchX, OpenSSH, and Sendmail.
Platforms Affected
Caldera OpenLinux Server 3.1
Caldera OpenLinux Server 3.1.1
Caldera OpenLinux Workstation 3.1
Caldera OpenLinux Workstation 3.1.1
Conectiva Linux 5.0
Conectiva Linux 5.1
Conectiva Linux 6.0
Conectiva Linux 7.0
Conectiva Linux 8.0
FreeBSD FreeBSD 4.0
FreeBSD FreeBSD 4.1
FreeBSD FreeBSD 4.1.1
FreeBSD FreeBSD 4.2
FreeBSD FreeBSD 4.3
HP Secure OS software for Linux 1.0
MandrakeSoft Corporate Server 1.0.1
MandrakeSoft Linux Mandrake 7.1
MandrakeSoft Linux Mandrake 7.2
MandrakeSoft Linux Mandrake 8.0
MandrakeSoft Linux Mandrake 8.1
MandrakeSoft Linux Mandrake 8.2
MandrakeSoft Single Network Firewall 7.2
RedHat Linux 6.2 alpha
RedHat Linux 6.2 i386
RedHat Linux 6.2 sparc
RedHat Linux 7.0 alpha
RedHat Linux 7.0 i386
RedHat Linux 7.1 alpha
RedHat Linux 7.1 i386
RedHat Linux 7.1 ia64
RedHat Linux 7.2 i386
RedHat Linux 7.2 ia64
Trustix Secure Linux 1.1
Trustix Secure Linux 1.2
Trustix Secure Linux 1.5
Components Affected
LBL libpcap 0.7.1
LBL tcpdump 3.6.2
LBL tcpdump 3.7.1
Recommendations
Block external access at the network boundary, unless service is required by external parties.
Filter untrusted network traffic at border routers and network firewalls.
Run all server processes as non-privileged users with minimal access rights.
Perform all tasks with the minimal privileges possible.
It has been recommended that users that require tcpdump or libpcap use either a known, good version of tcpdump 3.62, tcpdump 3.71 or libpcap 0.71.
LBL libpcap 0.7.1:
LBL tcpdump 3.6.2:
LBL tcpdump 3.7.1:
References
Source: Latest libpcap & tcpdump sources from tcpdump.org contain a trojan.
URL: http://hlug.fscker.com/
Credits
Discovery of this vulnerability credited to Russell Adams , Mathew Solnik , and Scott Stout .
Copyright (c) 2002 by Symantec Corp.
Permission to redistribute this alert electronically is granted as long as it is not edited in any way unless authorized by Symantec Security Response. Reprinting the whole or part of this alert in any medium other than electronically requires permission from symsecurity@symantec.com.
Disclaimer
The information in the advisory is believed to be accurate at the time of publishing based on currently available information. Use of the information constitutes acceptance for use in an AS IS condition. There are no warranties with regard to this information. Neither the author nor the publisher accepts any liability for any direct, indirect, or consequential loss or damage arising from use of, or reliance on, this information.
Symantec, Symantec products, Symantec Security Response, and SymSecurity are registered trademarks of Symantec Corp. and/or affiliated companies in the United States and other countries. All other registered and unregistered trademarks represented in this document are the sole property of their respective companies/owners.
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