Vulnerability when Network Address Translation (NAT) is enabled in Linux 2.2.10 and earlier with ipchains, or FreeBSD 3.2 with ipfw, allows remote attackers to cause a denial of service (kernel panic) via a ping -R (record route) command.
http://www.kernel.org/pub/linux/kernel/v2.2/patch-2.2.11.gz
http://www.iss.net/security_center/static/7257.php