isakmp_sub_print in tcpdump 3.6 through 3.7.1 allows remote attackers to cause a denial of service (CPU consumption) via a certain malformed ISAKMP packet to UDP port 500, which causes tcpdump to enter an infinite loop.
http://www.securityfocus.com/bid/6974
http://www.redhat.com/support/errata/RHSA-2003-214.html
http://www.redhat.com/support/errata/RHSA-2003-085.html
http://www.redhat.com/support/errata/RHSA-2003-032.html
http://www.novell.com/linux/security/advisories/2003_015_tcpdump.html
http://www.mandrakesoft.com/security/advisories?name=MDKSA-2003:027
http://www.iss.net/security_center/static/11434.php
http://www.idefense.com/advisory/02.27.03.txt
http://www.debian.org/security/2003/dsa-255
http://marc.info/?l=bugtraq&m=104678787109030&w=2
http://marc.info/?l=bugtraq&m=104637420104189&w=2
http://distro.conectiva.com.br/atualizacoes/?id=a&anuncio=000629