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.
Who uses Windows Firewall?
80 buck for relative peace of mind on the home computer is ok by me. Of course hardening the PC itself is important as well.
But I see your point.
Please don't encourage any Windows PC users to switch to a secure and modern OS, such as OSX.
The natural law of survival of the fittest and extinction of the inept must be kept intact.
Uh Oh. Now our RT will call you out on posting exploit code.... :)
Don't forget that ASIC and FPGA's are hardware ... crap ... even those have some kind of software.
Don't do that!!! I had to look to see if mine was still back there...
I wouldn't be without it.
Hahaha
I have a hardware firewall in my router, I use WindowsXP's firewall and I use Zone Alarm firewall. I use SpyWare Blaster which sort of locks down your computer in advance of assaults. Also Windows Defender and McAfee anti virus. Also AVG anti virus. Some of these are run only when I remember to. Once a week or so.
ROFL! I was just about to post another script to open a remote shell on the windows machine after you get the firewall down! :p
PS: I doubt anyone could kill IPTables in such a way =)
How do I check if ICS is active and if so, how do I disable it?
Yeah, but how many high speed internet providers supply decent hardware to non technical end users? I've been in too many homes and been appalled by junk provided by the internet provider.
Although, I recently went DSL and SBC provided me with a great router/firewall.
.
Essentially, ICS is used when one computer on a network is the computer that actually has Internet access--usually over a modem.
ICS is used by that computer to share it's internet access with other computers on the network. It's usually used by dial-up accounts.
If you do not have your home computers set up in the above configuration, don't worry about it.
I'm amused by sheeple who willingly choose Windows when there are far better choices out there.
Anyone dependent on the Microsoft firewall is just asking for trouble anyway.
I am amazed how many people I know who don't even back up their hard drive on a regular basis.
LOL--who in the world trusts their computer to the Windows firewall? Way too funny!!
mepis
One of the more interesting hacks I've seen on locking down a Linux-based firewall is to remove the 'poweroff' from your shutdown sequence. You basically boot the PC up, set up your firewall =exactly= as you want it, then "shutdown".
However, without the poweroff, you'll basically end up with a box that has all services turned off, and the disks unmounted. The only thing running is the kernel ... and iptables, which runs as a kernel process! The thing will be as close to not running as possible, but would still be passing packets. Of course, if you need to make a change to your rules, you have to physically power off and reboot, then make your changes and 'shutdown' again. This makes this more of an interesting hack than something actually useful, but I thought it was cool. Of course, you also don't want your init scripts to kill your ethernet while it's killing other processes as well.
Very interesting.
Requires ICS is enabled? LOL are you really that desperate to post Windows hacks? I guess the larger point that some people are fanatical about hacking Windows was well made however.
ping
Your code sample brings one thought to bear: Death to VB!
ping...
Me neither...
Not if people don't know how to use it...8^)
Dude, ICS is disabled by default, and his point was that most people don't need ICS enabled--so on most computers it's disabled anyways...
Obviously, nor is it hardly ever enabled by anyone else, making this whole thread a waste of bandwidth to anyone other than those whose lives seem to revolve around glorifying the latest Windows hack.
They're not glorifying the latest Windows hack--it makes news because 90+% of people use Windows...
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.