Gentoo Linux Security Advisory                           GLSA 200404-03
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
                                              http://security.gentoo.org
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

  Severity: High
     Title: Tcpdump Vulnerabilities in ISAKMP Parsing
      Date: March 31, 2004 
      Bugs: #38206, #46258
        ID: 200404-03

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

Synopsis
========

There are multiple vulnerabilities in tcpdump and libpcap related to
parsing of ISAKMP packets.

Background
==========

Tcpdump is a program for monitoring IP network traffic. Libpcap is a
supporting library which is responsibile for capturing packets off a
network interface.

Affected packages
=================

    -------------------------------------------------------------------
     Package               /    Vulnerable    /             Unaffected
    -------------------------------------------------------------------
     net-analyzer/tcpdump        <= 3.8.1                  >= 3.8.3-r1
     net-libs/libpcap           <= 0.8.1-r1                >= 0.8.3-r1

Description
===========

There are two specific vulnerabilities in tcpdump, outlined in [
reference 1 ]. In the first scenario, an attacker may send a
specially-crafted ISAKMP Delete packet which causes tcpdump to read
past the end of its buffer. In the second scenario, an attacker may
send an ISAKMP packet with the wrong payload length, again causing
tcpdump to read past the end of a buffer.

Impact
======

Remote attackers could potentially cause tcpdump to crash or execute
arbitrary code as the 'pcap' user.

Workaround
==========

There is no known workaround at this time. All tcpdump users are
encouraged to upgrade to the latest available version.

Resolution
==========

All tcpdump users should upgrade to the latest available version.
ADDITIONALLY, the net-libs/libpcap package should be upgraded.

    # emerge sync

    # emerge -pv ">=net-libs/libpcap-0.8.3-r1" 
">=net-analyzer/tcpdump-3.8.3-r1"
    # emerge ">=net-libs/libpcap-0.8.3-r1" ">=net-analyzer/tcpdump-3.8.3-r1"

References
==========

  [ 1 ]  http://www.rapid7.com/advisories/R7-0017.html
  [ 2 ]  http://rhn.redhat.com/errata/RHSA-2004-008.html
  [ 3 ]  http://cve.mitre.org/cgi-bin/cvename.cgi?name=CAN-2003-0989

Concerns?
=========

Security is a primary focus of Gentoo Linux and ensuring the
confidentiality and security of our users machines is of utmost
importance to us. Any security concerns should be addressed to
security@gentoo.org or alternatively, you may file a bug at 
http://bugs.gentoo.org.