Date: Fri, 12 Jul 2002 13:46:02 -0700 (PDT)
From: FreeBSD Security Advisories <security-advisories@freebsd.org.>
To: Bugtraq <bugtraq@securityfocus.com.>
Subject: FreeBSD Security Advisory FreeBSD-SA-02:29.tcpdump
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FreeBSD-SA-02:29 Security Advisory
The FreeBSD Project
Topic: Buffer overflow in tcpdump when handling NFS packets
Category: contrib
Module: tcpdump
Announced: 2002-07-12
Credits: [email protected]
Affects: All releases prior to and including 4.6-RELEASE
FreeBSD 4.6-STABLE prior to the correction date
Corrected: 2002-07-05 13:24:57 UTC (RELENG_4)
2002-07-12 13:29:47 UTC (RELENG_4_6)
2002-07-12 13:31:10 UTC (RELENG_4_5)
2002-07-12 13:31:44 UTC (RELENG_4_4)
FreeBSD only: NO
I. Background
The tcpdump utility is used to capture and examining network traffic.
II. Problem Description
Versions of tcpdump up to and including 3.7.1 contain a buffer
overflow that may be triggered by badly formed NFS packets, and
possibly other types of packets.
III. Impact
It is not currently known whether this buffer overflow is exploitable.
If it were, an attacker could inject specially crafted packets into
the network which, when processed by tcpdump, could lead to arbitrary
code execution with the privileges of the user running tcpdump
(typically `root').
IV. Workaround
There is no workaround, other than not using tcpdump.
V. Solution
Do one of the following:
1) Upgrade your vulnerable system to 4.6-STABLE; or to the RELENG_4_6,
RELENG_4_5, or RELENG_4_4 security branch dated after the correction
date (4.6-RELEASE-p2, 4.5-RELEASE-p8, or 4.4-RELEASE-p15).
2) To patch your present system:
The following patch has been verified to apply to FreeBSD 4.4, 4.5, and
4.6 systems.
a) Download the relevant patch from the location below, and verify the
detached PGP signature using your PGP utility.
# fetch ftp://ftp.FreeBSD.org/pub/FreeBSD/CERT/patches/SA-02:29/tcpdump.patch
# fetch ftp://ftp.FreeBSD.org/pub/FreeBSD/CERT/patches/SA-02:29/tcpdump.patch.asc
b) Execute the following commands as root:
# cd /usr/src
# patch < /path/to/patch
# cd /usr/src/usr.sbin/tcpdump
# make depend && make && make install
VI. Correction details
The following list contains the revision numbers of each file that was
corrected in FreeBSD.
Path Revision
Branch
- -------------------------------------------------------------------------
src/contrib/tcpdump/interface.h
RELENG_4 1.4.2.3
RELENG_4_6 1.4.2.1.6.1
RELENG_4_5 1.4.2.1.4.1
RELENG_4_4 1.4.2.1.2.1
- -------------------------------------------------------------------------
VII. References
<URL:http://rhn.redhat.com/errata/RHSA-2002-094.html>;
<URL:http://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=55145>;
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