Windows Server 2003 and XP SP2 LAND attack vulnerability
Hello, everyone.
Windows Server 2003 and XP SP2 (with Windows Firewall turned off) are
vulnerable to LAND attack.
LAND attack:
Sending 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.
Tools used:
IP Sorcery for creating malicious packet, Ethereal for sniffing it and
tcpreplay for replaying.
Results:
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.
Vulnerable operating systems:
Windows 2003
XP SP2
other OS not tested (I have other things to do currently ? like checking
firewalls on my networks ;) )
Solution:
Use Windows Firewall on workstations, use some firewall capable of detecting
LAND attacks in front of your servers.
Ethic:
Microsoft was informed 7 days ago (25.02.2005, GMT +1, local time), NO answer
received, so I decided to share this info with security community.
Dejan Levaja
System Engineer
Bulevar JNA 251
11000 Belgrade
Serbia and Montenegro
cell: +381.64.36.00.468
email: dejan@xxxxxxxxxx