Re: Windows Server 2003 and XP SP2 LAND attack vulnerability
I can replicate this using hping2 on a Linux 2.2.19 box targeting a Windows
XP SP2 box (fully patched) with no firewall active on the same subnet. The
packet sent has the SYN flag set (-S) and a spoofed source address (-a). The
source and destination ports must be the same and open on the target
machine. I tried ports 135, 139, 445, and 3389, and all of them raised the
CPU usage of the System process to 100% for the duration of the attack and
for about 10 seconds afterwards. The effect is quite dramatic, but the
system isn't frozen per se. You can still interact with it, albeit very
slowly. Task Manager responds updates its window appropriately, for
instance, and you can send events to other applications.
One version of the command I used was (from a machine at 192.168.1.5):
hping2 192.168.1.1 -s 135 -p 135 -S -a 192.168.1.1
That should have the desired effect.
--
Patrick Chipman
Institute for Intelligent Systems
http://www.iismemphis.org
----- Original Message -----
From: "Jon O." <jono@xxxxxxxxxxxxxxxxxx>
To: "Dejan Levaja" <dejan@xxxxxxxxxx>
Cc: <bugtraq@xxxxxxxxxxxxxxxxx>
Sent: Monday, March 07, 2005 3:55 PM
Subject: Re: Windows Server 2003 and XP SP2 LAND attack vulnerability
All:
I would like to hear from someone who can reproduce this. If you can,
please send
details with OS, patches installed, pcaps, etc. not a report of what tools
you used
to create the packet, sniff and replay the results. I've tested this and
either my
machines are magically protected from this attack, or it is invalid
(despite what
the press might say). I'd like some outside corroboration of this attack.
On 05-Mar-2005, Dejan Levaja wrote:
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