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SuSE Security Announcement: tcpdump

Nov 17, 2000, 20:38 (0 Talkback[s])
(Other stories by Roman Drahtmueller)

Date: Fri, 17 Nov 2000 16:39:16 +0100 (MET)
From: Roman Drahtmueller draht@suse.de
To: suse-security-announce@suse.de
Subject: [suse-security-announce] SuSE Security Announcement: tcpdump (SuSE-SA:2000:46)


                        SuSE Security Announcement

        Package:                tcpdump
        Announcement-ID:        SuSE-SA:2000:46
        Date:                   Friday, November 17th, 2000 16:00 MEST
        Affected SuSE versions: 6.0, 6.1, 6.2, 6.3, 6.4, 7.0
        Vulnerability Type:     remote denial of service
        Severity (1-10):        6
        SuSE default package:   yes
        Other affected systems: systems using the same versions of tcpdump
                                and the necessary libraries

    Content of this advisory:
        1) security vulnerability resolved: tcpdump
           problem description, discussion, solution and upgrade information
        2) clarification, pending vulnerabilities, solutions, workarounds
        3) standard appendix (further information)

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

tcpdump is a widespread network/packet analysis tool, also known as a packet sniffer, used in unix/unix-like environment. Several overflowable buffers have been found in SuSE's version of tcpdump that could allow a remote attacker to crash the local tcpdump process. Since tcpdump may be used in combination with intrusion detection systems, a crashed tcpdump process may disable the network monitoring system as a whole. The FreeBSD team who found these vulnerabilities also reported that tcpdump's portion of code that can decode AFS ACL (AFS=Andrew File System, a network filesystem, ACL=Access Control List) packets is vulnerable to a (remotely exploitable) buffer overrun attack that could allow a remote attacker to execute arbitrary commands as root since the tcpdump program usually requires root privileges to gain access to the raw network socket. The versions of tcpdump as shipped with SuSE distributions do not contain the AFS packet decoding capability and are therefore not vulnerable to this second form of attack.

A temporary workaround for the tcpdump problems other than not using tcpdump in the first place does not exist. However, we provide update packages for the affected SuSE distributions. We recommend an upgrade using the packages that can be found using the URLs below.

Note: Please note that there is only one source rpm package but two binary rpm packages. tcpdump*.rpm is the rpm for the tcpdump program, and libpcapn*.rpm is the packet capture library that is required by tcpdump at compile time. In order to remove the security vulnerability in tcpdump, it is necessary to update the tcpdump rpm package only. The libpcapn package with the static library is provided for consistency and compatibility because it will be generated if the binary packages are rebuilt from the source rpm.

To check if your system has the vulnerable package installed, use the command `rpm -q ´. If applicable, please choose the update package(s) for your distribution from the URLs listed below and download the necessary rpm files. Then, install the package using the command `rpm -Uhv file.rpm´. rpm packages have an internal md5 checksum that protects against file corruption. You can verify this checksum using the command (independently from the md5 signatures below)
`rpm --checksig --nogpg file.rpm',
The md5 sums under each package are to prove the package authenticity, independently from the md5 checksums in the rpm package format.

i386 Intel Platform:

SuSE-7.0
ftp://ftp.suse.com/pub/suse/i386/update/7.0/d1/libpcapn-0.4a6-279.i386.rpm
f4e4a9231b695e1cf5eef0ad09871c34
ftp://ftp.suse.com/pub/suse/i386/update/7.0/n1/tcpdump-3.4a6-280.i386.rpm
ba711cf2fab14218752603fa5a941721
source rpm:
ftp://ftp.suse.com/pub/suse/i386/update/7.0/zq1/tcpdump-3.4a6-280.src.rpm
d4c5902c50d6a321e2c4ed665fcd1962

SuSE-6.4
ftp://ftp.suse.com/pub/suse/i386/update/6.4/d1/libpcapn-0.4a6-279.i386.rpm
a1030d64ca4ca86a08b6bee5dc9cff78
ftp://ftp.suse.com/pub/suse/i386/update/6.4/n1/tcpdump-3.4a6-280.i386.rpm
12335bf0055c6a9b915044a95a544aaa
source rpm:
ftp://ftp.suse.com/pub/suse/i386/update/6.4/zq1/tcpdump-3.4a6-280.src.rpm
dca26c3e5ef81f449cd43ab4d1f91b63

SuSE-6.3
ftp://ftp.suse.com/pub/suse/i386/update/6.3/d1/libpcapn-0.4a6-279.i386.rpm
13c90044ed57792090163a33ffb69ecf
ftp://ftp.suse.com/pub/suse/i386/update/6.3/n1/tcpdump-3.4a6-280.i386.rpm
646de6c14a2d4988d0c684a42b4eef58
source rpm:
ftp://ftp.suse.com/pub/suse/i386/update/6.3/zq1/tcpdump-3.4a6-280.src.rpm
46980acd95607d4a9c61ca0f75c33fc2

SuSE-6.2
ftp://ftp.suse.com/pub/suse/i386/update/6.2/d1/libpcapn-0.4a6-279.i386.rpm
d058e563ad10daf078f5909a6b8ff288
ftp://ftp.suse.com/pub/suse/i386/update/6.2/n1/tcpdump-3.4a6-280.i386.rpm
f5209f1f1433b0a55676f29451a2ef1b
source rpm:
ftp://ftp.suse.com/pub/suse/i386/update/6.2/zq1/tcpdump-3.4a6-280.src.rpm
cd34cd3feedbe0568d76dd9a406cec79

SuSE-6.1
ftp://ftp.suse.com/pub/suse/i386/update/6.1/d1/libpcapn-0.4a6-279.i386.rpm
ef454e2d23e410be82aa9f0634bcc9dc
ftp://ftp.suse.com/pub/suse/i386/update/6.1/n1/tcpdump-3.4a6-280.i386.rpm
9f6ebff316039421ee00121a0e8720fa
source rpm:
ftp://ftp.suse.com/pub/suse/i386/update/6.1/zq1/tcpdump-3.4a6-280.src.rpm
d1148813da9610f940ecdbd462ab2541

SuSE-6.0
Please use the package for the SuSE-6.1 distribution.

Sparc Platform:

SuSE-7.0
ftp://ftp.suse.com/pub/suse/sparc/update/7.0/d1/libpcapn-0.4a6-279.sparc.rpm
412a7db34985555705d8d43f2853ae4e
ftp://ftp.suse.com/pub/suse/sparc/update/7.0/n1/tcpdump-3.4a6-280.sparc.rpm
a177326150a65d78212cebba90b88201
source rpm:
ftp://ftp.suse.com/pub/suse/sparc/update/7.0/zq1/tcpdump-3.4a6-280.src.rpm
49f1f0420dd84070dcd9a67452770e75

AXP Alpha Platform:

SuSE-6.4
ftp://ftp.suse.com/pub/suse/axp/update/6.4/d1/libpcapn-0.4a6-279.alpha.rpm
096522f46ab70d92dda17b4ca33b4181
ftp://ftp.suse.com/pub/suse/axp/update/6.4/n1/tcpdump-3.4a6-280.alpha.rpm
84ca9a93a2201f7046446ed07107cbbc
source rpm:
ftp://ftp.suse.com/pub/suse/axp/update/6.4/zq1/tcpdump-3.4a6-280.src.rpm
07ed654ad1693dca5fd433572b3689c9

SuSE-6.3
ftp://ftp.suse.com/pub/suse/axp/update/6.3/d1/libpcapn-0.4a6-280.alpha.rpm
747c22bb722da5df7fe3cfc252bdc545
ftp://ftp.suse.com/pub/suse/axp/update/6.3/n1/tcpdump-3.4a6-281.alpha.rpm
dbe10ebc95a2371d01df729af265bdf6
source rpm:
ftp://ftp.suse.com/pub/suse/axp/update/6.3/zq1/tcpdump-3.4a6-281.src.rpm
8f6e48e693fc465c1f60b6cee944c27c

PPC Power PC Platform:

SuSE-7.0
ftp://ftp.suse.com/pub/suse/ppc/update/7.0/d1/libpcapn-0.4a6-279.ppc.rpm
140b95ffb3be2c2915327d4798b16dd0
ftp://ftp.suse.com/pub/suse/ppc/update/7.0/n1/tcpdump-3.4a6-280.ppc.rpm
7f71b4ac17e3ad2c071e712c137a7c28
source rpm:
ftp://ftp.suse.com/pub/suse/ppc/update/7.0/zq1/tcpdump-3.4a6-280.src.rpm
d9db0e99e91d8981efebafd6a539566f

SuSE-6.4
ftp://ftp.suse.com/pub/suse/ppc/update/6.4/d1/libpcapn-0.4a6-279.ppc.rpm
ed8697842867cbb5457c03015c117131
ftp://ftp.suse.com/pub/suse/ppc/update/6.4/n1/tcpdump-3.4a6-280.ppc.rpm
782dc3faba33cf1b2d9e6ef95caf4107
source rpm:
ftp://ftp.suse.com/pub/suse/ppc/update/6.4/zq1/tcpdump-3.4a6-280.src.rpm
318bf758753d9728f101de2101ad3227


2) Pending vulnerabilities in SuSE Distributions and Workarounds:

Clarification: In my message (Subject: "SuSE: miscellaneous"), dated Wed, 15 Nov 2000, concerning the paragraph about runtime linking problems in gs (GhostScript) , I have stated that the problem will be fixed in future versions of the SuSE distribution. This does not touch the fact that we will of course provide fixes for the older distributions.

- pine

We're still working on the packages for the version 4.30 (stability problems).

- ppp

The ppp "deny_incoming" problem as announced by FreeBSD Security Advisory FreeBSD-SA-00:70.ppp-nat is FreeBSD specific and does not affect the SuSE distribution.

- vixie cron

Michal Zalewski reported security problems in Paul Vixie's cron implementation that is commonly used in Linux distributions. Due to correct permissions on the directory /var/spool/cron, the SuSE cron package is not affected by the problem.


3) standard appendix:

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 annoucements 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.


Regards,
Roman Drahtmüller.
- - --

 -                                                                      -
| Roman Drahtmüller        draht@suse.de //          "Caution: Cape does |
  SuSE GmbH - Security           Phone: //       not enable user to fly."
| Nürnberg, Germany     +49-911-740530 // (Batman Costume warning label) |
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