By sending a TCP packet with SYN flag set, source and destination IP address and source and destination port as of destination machine, results in 15-30 seconds DoS condition.

Vulnerable Systems:
* Microsoft Windows XP SP 2
* Microsoft Windows XP SP 1
* Microsoft Windows XP
* Microsoft Windows 2003 Server
* Microsoft Windows 2003 Server SP 1
* Microsoft Windows 2000 SP 4

By sending single LAND packet to file server causes Windows explorer freezing on all workstations currently connected to the server. CPU on server goes 100%. Network monitor on the victim server sometimes can not even sniff malicious packet. Using tcpreplay to script this attack results in total collapse of the network.

Workaround: Use build-in windows firewall to block open IPv6 ports (port 135 is open by default). Popular firewalls like zone alarm, sygate personal firewall and agnitum outpost firewall do not filter ipv6 so the attack has the same effect.

http://www.securiteam.com/windowsntfocus/5EP0C2KFQA.html