Posted on 10/31/2006 4:03:06 PM PST by ShadowAce
Hackers have published code that could let an attacker disable the Windows Firewall on certain Windows XP machines.
The code, which was posted on the Internet early Sunday morning, could be used to disable the Windows Firewall on a fully patched Windows XP PC that was running Windows' Internet Connection Service (ICS). This service allows Windows users to essentially turn their PC into a router and share their Internet connection with other computers on the local area network (LAN.) It is typically used by home and small-business users.
The attacker could send a malicious data packet to another PC using ICS that would cause the service to terminate. Because this service is connected to the Windows firewall, this packet would also cause the firewall to stop working, said Tyler Reguly, a research engineer at nCircle Network Security Inc., who has blogged about the issue.
"Once the firewall is down, where's your line of defense?" he said Monday, in an interview.
By knocking off the Windows Firewall, a criminal could open the door to new types of attacks, but there are a number of factors that make such an attack scenario unlikely, Reguly said.
For example, the attacker would have to be within the LAN in order to make the attack work, and, of course, it would only work on systems using ICS, which is disabled by default. Furthermore, the attack would have no effect on any third-party firewall being used by the PC, Reguly said.
Users can avoid the attack by disabling ICS, Reguly said. But this will also kill the shared Internet connection.
An easier solution, may be for ICS users to simply move their networks onto a router or NAT (Network Address Translation) device, said Stefano Zanero, chief technology officer with Secure Network SRL. "They are so cheap right now, and in many cases they offer better protection and a easier administration of your LAN," he said via instant message.
Windows XP appears to be the only platform affected by this attack, which has not been successfully reproduced on Windows Server 2003, Reguly said.
Microsoft 's initial investigation into the matter "has concluded that the issue only impacts users of Windows XP," the company's public relations agency said Monday in a statement. "Microsoft is not aware of any attacks attempting to use the reported vulnerability or of customer impact at this time."
Where it should be ... on a network appliance.
Oh well that's OK then. It'll only affect a few million people.
Do these people really have nothing better to do?
The arms race continues.
Ya gotta wonder, don't ya?
Short sighted thinking there when it comes to the 3rd party firewall. If the attacker can shut down the Windows firewall, what else could the attacker do if they are interested in doing something? There would have to be a hole that would allow them to run their code to shut down the firewall. If they've breached the system to that point, they can likely do any number of other things that might not be in the proof of concept code.
I was thinking the same thing.
Does anyone still use ICS?
I've never used the windows firewall. I don't think it's all that good.
An interesting, but lame hack. You've already got to be inside the firewall to do it. Somebody who's building their network using ICS is already not very serious about security.
The firewall belongs on a box upstream of the LAN anyway.
Why not just get a cheap router with a hardware-based firewall built in?
Dial-up users still gotta use it, I believe.
Anything but a hardware firewall is useless anyway.
Oh yeah... You have a point there. And here I was hoping for a minor MSFT screwup.
Remember, we are dealing with users here.
Users....at home.
Appliance? My stove is ok. Fridge is keeping the beer cold. Check.
Technically, there's no such thing. What you're thinking of is an appliance that only runs firewall software. While they're usually better than the Windows firewall, they still consist of just software.
Actually no they don't. Finding exploits and examining code is literally the purpose of some of these hackers' lives.
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