Researchers discover WPA2 vulnerability

Researchers at wireless security company AirTight Networks have uncovered a vulnerability in the widely used WPA2 security protocol, part of the 802.11 standard. The vulnerability, termed "Hole 196", which can be exploited by attackers already authenticated to the network, allows decryption of data sent by other users across the network.

Wireless encryption uses two keys to protect the communications, firstly a Pairwise Transient Key (PTK), unique to each client, and used to protect traffic between that client and the access point, and secondly, a Group Temporal Key (GTK) that is known to all clients on the network, and used to encrypt broadcast traffic (traffic sent to all clients connected to the network).

The attack does not rely on brute-forcing, or breaking of the AES encryption used to protect the communications. The vulnerability arises when a malicious client uses the GTK to send spoofed packets to another user on the network. GTKs do not have the ability to detect spoofed packets, an ability which does exist in PTKs.

Researcher Md Sohail Ahmad, who discovered the vulnerability, says it took around 10 lines of code added to open source driver software, and an off-the-shelf wireless adaptor in order to implement the exploit. By spoofing the MAC address of the access point, clients who receive the malicious packets, believe the sender to be the gateway, and respond using their PTK, which the attacker can then decrypt.

Exploiting the vulnerability is limited to users already authorised to the network, which mitigates the risk, but security studies repeatedly indicate security breaches from inside continue to be the biggest source of loss to businesses.

WPA2 is the latest encryption protocol available for wireless networking, and as yet, there is no successor ready to take its place in order to resolve this issue, it remains to be seen what the security community can devise to work around the problem in the protocol.

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I'm posting this on a stolen wi-fi via an unprotected router. All I did was enter 8 zeroes and the connection was configured. had to go off topic here.

hackson said,
I'm posting this on a stolen wi-fi via an unprotected router. All I did was enter 8 zeroes and the connection was configured. had to go off topic here.

if you had to enter 8 zeros then there was some type of wireless security on the device.

At list it wasn't as bad as a guy who I helped on a security matter once. It was twenty-six characters long. The trouble was it was the alphabet a to z in lower case.

YounGMessiah said,
/me glad for common sense

+1

And that common sense, for me, is to NOT use anything wireless. At least not on any computer that does anything.

cork1958 said,

+1

And that common sense, for me, is to NOT use anything wireless. At least not on any computer that does anything.

The problem here, is that this "exploit" is very easy to do with a wired network (i.e. a man in the middle attack)

Well this security issue can be patched on firmware like DD-WRT right?

because i run DD-WRT on my Asus WL-520gu router. but i guess if you already have to have access to the network to exploit this then it's not really that serious of a issue if they can't get in in the first place

Not really, the issue is fundamental to WPA, it's not just a problem with a specific implementation. Fixing it on a router could lead to it not working correctly with wireless clients. The only way to fix the issue is to update every device that implements WPA, to some new version of the protocol that doesn't suffer from this problem.

DaveLegg said,
Not really, the issue is fundamental to WPA, it's not just a problem with a specific implementation. Fixing it on a router could lead to it not working correctly with wireless clients. The only way to fix the issue is to update every device that implements WPA, to some new version of the protocol that doesn't suffer from this problem.

Maybe

Depends on the fix. Maybe the access point could try and detect spoofed packets, and drop them if there is a MAC/IP mismatch? I think that could fix it, without having to upgrade client firmware, however I see a lot of overhead in that method

rtire said,

Maybe

Depends on the fix. Maybe the access point could try and detect spoofed packets, and drop them if there is a MAC/IP mismatch? I think that could fix it, without having to upgrade client firmware, however I see a lot of overhead in that method

It's trivial to spoof a MAC address - in fact the vulnerability requires it so that's no protection.

M2Ys4U said,

It's trivial to spoof a MAC address - in fact the vulnerability requires it so that's no protection.

Well then coudn't you just filter by MAC address? I appreciate that in any case, each client would need to be configured manually in the access point.

Putting everything aside, isn't this just a wireless version of a "man in the middle" attack? Woudn't turning on "Wireless isolation" prevent this from happening? The access point would have ot make sure that packets can only flow from a client to the upstream route (by physical interfae)

rtire said,

Well then coudn't you just filter by MAC address?

Nah Mac address filtering isn't protection, due to the very reason that MAC addresses can be spoofed easily.

Anyway yeah, it sounds like a man in the middle attack to me but thats the problem, the wirless protocols are supposed to protect somewhat against it as far as I'm aware. Clearly the risk is limited somewhat by the fact you have to already be on the network, but it could be an issue for work places and the like.

Smigit said,
Nah Mac address filtering isn't protection, due to the very reason that MAC addresses can be spoofed easily.

Anyway yeah, it sounds like a man in the middle attack to me but thats the problem, the wirless protocols are supposed to protect somewhat against it as far as I'm aware. Clearly the risk is limited somewhat by the fact you have to already be on the network, but it could be an issue for work places and the like.

Actually, I'm pretty sure you could filter by Mac/IP if each user was given a cert/key unique to them. However this would only be good for businesses.

Not really a big issue for non-businesses though, as man in the middle attack can be done on wired networks, and it's never really been a problem.

Pffft. If your network is setup to use WPA2, surely if you are going to be worried about encrypting data, you would be looking at the better security options available...?

Well for home users using WPA2 its not a big deal since only trusted people get into our networks usually. Everywhere i go i SSH tunnel/vpn anyways!

Backtrack + general residential area and a small dectionary = cracked networks. most people don't have great passwords so this exploit would be quite useful for experienced network analyses xD

Auzeras said,
Backtrack + general residential area and a small dectionary = cracked networks. most people don't have great passwords so this exploit would be quite useful for experienced network analyses xD

IF that's how you spell "dictionary" in your "dectionary", then I have nothing to worry about with my networks.

not really a problem for most users, sensitive data is sent over SSL anyway. Even live messenger chat conversation are encrypted.

The big problem i see with this is sending sensitive files to a server on a business network

XerXis said,
not really a problem for most users, sensitive data is sent over SSL anyway. Even live messenger chat conversation are encrypted.

Most common messenger protocols (including WLM/MSN) aren't encrypted, run wireshark while you are IM'ing and see for yourself.

Shadrack said,
Would your data still be encrypted if you had an SSL connection (https) despite this security hole?

That's completely separate, they could get the data you are sending still but it would be encrypted and would have to be brute forced.

omnicoder said,

That's completely separate, they could get the data you are sending still but it would be encrypted and would have to be brute forced.

Well, that's all I really care about. Your data hits lots of nodes before it gets to it's destination.

By default many people just take their wireless router home and plug it in and never bother to turn on the security.........so I dont think there would be a big focus on this considering how many people out there could be easily taken with less work...

TechGuyPA said,
By default many people just take their wireless router home and plug it in and never bother to turn on the security.........so I dont think there would be a big focus on this considering how many people out there could be easily taken with less work...

That's why most ISP's in Portugal, who provide the routers, automatically encrypt the network.

TechGuyPA said,
By default many people just take their wireless router home and plug it in and never bother to turn on the security.........so I dont think there would be a big focus on this considering how many people out there could be easily taken with less work...

I disagree. Walking down my street with my iPhone virtually every wifi signal is protected.

TechGuyPA said,
By default many people just take their wireless router home and plug it in and never bother to turn on the security.........so I dont think there would be a big focus on this considering how many people out there could be easily taken with less work...

I think you'll find that virtuall all routers bought from the shelves these days already have encryption turned on.

testman said,

I think you'll find that virtuall all routers bought from the shelves these days already have encryption turned on.

If you can call WEP encryption

ccoltmanm said,

I disagree. Walking down my street with my iPhone virtually every wifi signal is protected.

Maybe your holding your iPhone wrong.

TechGuyPA said,
By default many people just take their wireless router home and plug it in and never bother to turn on the security.........so I dont think there would be a big focus on this considering how many people out there could be easily taken with less work...

I've got four unprotected routers around me, Bloody neighbours don't know anything.... I think we need to sort out this problem first before moving on with WPA3 or whatever they'll name it.

3Grey said,

I've got four unprotected routers around me, Bloody neighbours don't know anything.... I think we need to sort out this problem first before moving on with WPA3 or whatever they'll name it.

Some routers (older Actiontec MI424WR models sold to Verizon for FIOS usage) don't even support WPA, let alone WPA2 (and WPA and WEP have much more serious flaws). Much more horrifying are the sheer number of wireless *adapters* in general use (older card or USB and built-in wireless, especially older laptops, notebooks, and netbooks) that don't support WPA2 either (or, just as bad, are running Windows XP with Service Pack 2 or earlier, which has known problems with the latest Windows XP drivers for most wireless adapters that support WPA2). Unless both adapter and router are set to use WPA2 exclusively, any one of a dozen conditions could force the connection to use plain WPA, which is far more vulnerable than WPA2.

ccoltmanm said,

I disagree. Walking down my street with my iPhone virtually every wifi signal is protected.


"Protected" with a password or protected with WPA/WPA2 encryption? Those two are very different things, you know.

ccoltmanm said,
I disagree. Walking down my street with my iPhone virtually every wifi signal is protected.

+1

Every network I've seen around here is encrypted. I think it depends where you are though, America is probably a damn site less secure than the UK. (No offence American Neowinians)

3Grey said,

I've got four unprotected routers around me, Bloody neighbours don't know anything.... I think we need to sort out this problem first before moving on with WPA3 or whatever they'll name it.


If you lived next to me, I would be one of those bloody neighbours that don't know anything. But you'd need to somehow bypass the VPN to get service.

souldreamer said,

That's why most ISP's in Portugal, who provide the routers, automatically encrypt the network.

Yeah, that's right, but with the help of a simple android phone (w/wifi) and a small app It's very easy to access to internet cause most users don't change the default wpa pass of their networks...

I took a drive on the main highway through Montreal a few months ago.. Left my Laptop on just gathering a list of network ssid's and if they were encrypted or not.. It came out to about 40% open, and another 40% WEP ( which is basically open.. )

People worry much about sites like Facebook when really it's the networks we use that pose the real weak link in data security. Just shows the need for widespread encryption.

McDave said,
People worry much about sites like Facebook when really it's the networks we use that pose the real weak link in data security. Just shows the need for widespread encryption.

Maybe it's both.

Just a bad thing if your using at a hotel, public area, etc thats all.. home users are fine unless your parents are crazy to crack it and see what your "really" doing.. lol

TheNay said,
Just a bad thing if your using at a hotel, public area, etc thats all.. home users are fine unless your parents are crazy to crack it and see what your "really" doing.. lol

Most hotels and other hotspots that I've seen aren't encrypting their connection anyway. They just have a portal to allow entering code, etc. Businesses, schools, institution, etc., is where the main problem would be.

You still need to be authenticated to the network before you can cause any real damage, so it's not a problem for general users.

Piggy said,
You still need to be authenticated to the network before you can cause any real damage, so it's not a problem for general users.

which would happen if you say left your lappy lying round and it got stolen