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Sophos Researcher Suggests Password 'Free' to Spur Wi-Fi Encryption
An anonymous reader writes "In the wake of concerns about FireSheep sniffing credentials from people using unencrypted public WiFi hotspots, a security researcher has proposed that the problem does not just lie with big websites like Facebook, but also with those who provide free wireless internet access. Chet Wisniewski, a researcher at security firm Sophos, proposes that all free WiFi hotspots should be encrypted — with the password 'free.' ''I propose standard adoption of WPA2 and a default password of "free." Whenever you wish to connect to complimentary WiFi, you select "Courtyard Marriott" or "Starbucks" like you always have, but you are then prompted for a password. Just type "free". It's not hard. In fact, operating system vendors could even program your PC to automatically try the password "free" before prompting you for a password on the assumption that you might be selecting a free service.'"
... just keep in mind that with WPA, the initial password is just used for connecting to the network, after which a session password is shared (right? pretty sure I'm right about that). So, technically, it would prevent someone from stealing your interwebs as long as you were already connected. Now, the guy who got to Starbucks before you and started sniffing before you did, he definitely has your personal information now, and this is a stupid idea.
Maybe he hasn't noticed that wireshark can decrypt WPA2 traffic so long as the network is being sniffed when the client originally connects.
... is 8 characters.
No.
capitals matter. and don't WPA2 phrases have to be at least 8 characters?
That a security research doesn't know better than this. Encryption with a PSK is useless as far as sidejacking is concerned. There is no decent client to client encryption unless you use WPA/2 Enterprise.
To suggest otherwise is bullshit, and he should be blaming the websites who are the problem.
If you ignore ACs because they are anonymous - you're an idiot.
Except when you're signifying an explicit string that will need to be readable by a computer. I would tend to err on the side of caution lest someone mistake my correct English punctuation for some sort of design intent.
Uhmm, maybe Sophos should invest in security training of their staff before they start selling supposed security products.
Excuse me, but please get off my Pennisetum Clandestinum, eh!
I'm afraid it is not that simple. You should always be wary of assuming that the rules used in your locality are universal. There are two styles in general use regarding punctuation and quotation marks. See the wikipedia entry on the subject:
In the U.S., the standard style is called American style, typesetters' rules, printers' rules, typographical usage, or traditional punctuation, whereby commas and periods are almost always placed inside closing quotation marks. This style of punctuation is common in the U.S., Canada, and in the U.K. in fiction and journalism.
The other standard style--called British style or logical punctuation--is to include within quotation marks only those punctuation marks that appeared in the quoted material, but otherwise to place punctuation outside the closing quotation marks.
Using the British style is less ambiguous in this case.
Unencrypted access points already use a standard password: the empty password. How is this any different?
Watch out! I tried typed in "Free" instead of of "free" like the Sophos Dude recommends and it wiped out all my time machine backups.
Well, at least that's what happened after I hard crashed my computer in the middle of a back up. But I'm sure it was sophos to blame.
Some drink at the fountain of knowledge. Others just gargle.
That's amazing! I've got the same password on my luggage!
-
- - You can't take something off the Internet! That's like trying to take pee out of a swimming pool.
1. Bring laptop with extra WiFi dongle into a public area.
2. Connect to Free WiFi spot using internal nic.
3. Act as an Access Point on second nic with a cooler sounding SSID.
4. NAT traffic to first WiFi net and grab everything of interest.
5. ???
6. Profit!!!1!!ONE!
Two guys, Diffie and Hellmann thought up a protocol that allows someone to listen to a "key exchange" without being able to determine the key that the two parties decide on.
One party decides on a base (g) and a modulus (p) and sends it to the other side. Our attacker will of course grab this info. Next each party will think up a number. Alice choses a, Bob choses b. Alice sends g^a mod p to Bob. Bob sends g^b mod p back to A. They key is then easy to calculate for Alice and bob. Alice does K = (g^b)^a = g^ab , while Bob does K = (g^a)^b = g^ab where the listening crook just has g^a and g^b and can't figure out a or b which are needed to find the key K in reasonable time.
Thus this protocol being known for almost 35 years allows easy encryption with a key that a eavesdropper cannot easily snoop..
There are so many ways this suggestion is wrong, it is not even funny.
TFA says WPA2 negotiates unique encryption keys with every computer that connects to it. This means you and I cannot spy on one another's traffic even when sharing access on the same access point. That's true, but anyone who can listen to the exchange and know the shared key will be able to learn the key. Plus, there is a very neat man in the middle attack.
Suppose that I am an evil sheep herder near a Starbuck cafe. Nothing prevents me from broadcasting a Wi-Fi beacon that announces that I am running a Starbuck access point. Here comes the sheep, who is really happyto see that the connection is secure. Hey, he used WPA2 and the "free" password, his packets are encrypted. Except they are all coming to my laptop. Oops!
The client has the keys only to decrypt traffic targeted to the client, not to other clients.
It is easy to bypass though by capturing a four-way handshake. A fake authentication can be used in order to have a client go though it again.
I've suggested this before a few times: http://it.slashdot.org/comments.pl?sid=457132&cid=22455074
Thing is he left out the part where there are two different modes of WPA2.
One (WPA2 PSK) where if everyone has the same password, it's still not secure (know the same key, sniff a session's 4 way handshake, and you can decrypt that session's traffic).
And one (the other WPA2) where it's supposedly more secure, but apparently still has problems: http://wifinetnews.com/archives/2010/07/researchers_hints_8021x_wpa2_flaw.html
Yeah, not so simple for Starbucks to get right...
Basically the WiFi standards bunch screwed up. So I actually blame them for a lot of the problems. So many years and they still haven't got WiFi to the level of TLS/HTTPS.
HTTPS doesn't solve the "stupid user problem", or the "browsers not warning users of changed CAs", but at least the tech/standard isn't that crap, it's more a people problem.
Uhmm, maybe Sophos should invest in security training of their staff before they start selling supposed security products.
He's neither a researcher (someone who works in the virus labs) nor an engineer (someone involved in development of our endpoint or management products). He's in sales. Nothing to see here people, move along.
Posting anonymously because I work there.
It's also perhaps worth noting that punctuation style is nothing at all to do with correct English. Punctuation is there to help understand the text, not to be part of it, and anyone who has ever trained as a copy editor knows that there are endless arguments over its proper use. If putting a full stop inside a quote means someone would naturally consider it part of the quoted material, it is clearly wrong.
From scarped cliff or quarried stone she cries "A thousand types are gone, I care for nothing, no not one."
If you put the password in the SSID so it's obvious, people won't have to guess if you're following that convention, or the convention that the password is "guest" or whatever.
Bill Stewart
New Fast-Compression-only CPR http://preview.tinyurl.com/dy575ks
Christopher Byrd has a simple modification to EAP-TLS that disables client certificate validation to provide more secure open wi-fi:
http://riosec.com/open-secure-wireless
This would require modifying only the Authenticator and the Supplicant, and it would be a simple modification to both.
Most of the Wifi systems are negotiating a random session key and using the password to authenticate it, so that's doing pretty much what you want.
However, they were mostly designed with the assumption that the objective is to prevent unauthorized access, not to protect the contents of the communications from eavesdropping, so the only way you can get encrypted sessions is to have password control, which is too bad.
Bill Stewart
New Fast-Compression-only CPR http://preview.tinyurl.com/dy575ks
Nevermind, read more posts and my question was answered.
On a WPA2 network, a user cannot eavesdrop on another user despite having the same key, because a unique handshake is performed when each user connects. Without the data that was passed in the handshake, an eavesdropper has no way of decrypting your traffic.
They can, however, force your connection to be reset, and when you reconnect they can capture the handshake. With the data that was passed in the handshake, they can decrypt all of your traffic.
Alexander Peter Kristopeit bought his basement from his mommy for one dollar.
Basically the WiFi standards bunch screwed up. So I actually blame them for a lot of the problems. So many years and they still haven't got WiFi to the level of TLS/HTTPS.
So use TLS/HTTPS over wifi. Why should the Wifi standard solve a problem that's already been solved? Wifi only has to be as secure as a wired network, at which point we can use all the protocols we use to keep our systems secure on the public internet.
Give me Classic Slashdot or give me death!
If only there were some sort of encryption standard that individual websites could implement which would cause the browser and server to encrypt the data between them. Some sort of socket layer which is secured via encryption. That would readily solve these problems. Oh computer gods, why hast thou forsaken us?
Check out my lame java blog at www.javachopshop.com
So use TLS/HTTPS over wifi. Why should the Wifi standard solve a problem that's already been solved
Solved already? Really? The last I checked "zillions" of sites don't support https. Slashdot for instance.
Some people can tunnel or VPN everything to a trusted gateway, but how many cafe users can do that? So the problem is NOT solved.
I hope you can figure out for yourself the difference between someone sniffing/exploiting traffic at a cafe, and someone doing it at the ISP or peering level.
Wifi only has to be as secure as a wired network
Yes, but it's _far_ from as secure at the moment. So they have failed.
1) It's harder to "sniff" a wired network that a wireless one. You need a free port for the former and you need to do stuff like mac-flooding (which can be detected). Or you need super duper Tempest stuff.
2) It's easier to set up a wired network where devices plugged into one port cannot snoop traffic from devices in another port. You could do this by either using what Cisco calls "port security" (other vendors have their own terms for it), or do "per port VLANs".
I was in the "hotel internet" line for a while, and we configured our switches so that guests plugged into a port could only talk to our gateway server. So guests using the wired connections were protected from other guests. They might not be protected from the NSA/CIA/KGB/FBI once their traffic leaves our control, but that's arguably beyond our responsibility.
Whereas wireless connections didn't allow us to protect guests from each other (at least while making it easy for guests to still use the system).
I am well aware that wireless connections can be DoSed more easily than wired connections, so no matter how much crypto you have, it's still jammable, but that would be a different threat level. Guests could still plug in to the wired port, lose the convenience, but still do their stuff.
FWIW: if a guest plugs into a wired port and intentionally/unintentionally tries to mess with the system we can usually figure out where that guest is, call the guest up and usually resolve things, even if we are in a different continent.
That's why after the WEP fiasco they should've handed the problem off to somebody competent. WEP was pretty much always a joke, because you really do need a lot more security when things are going over the air than you do when they're going over the wire. At least when things are going over the wire you need some access to the equipment relaying the messages. With wireless you don't even need that.
Because they screwed up: http://wiki.wireshark.org/HowToDecrypt802.11
"WPA and WPA2 use keys derived from an EAPOL handshake to encrypt traffic. Unless all four handshake packets are present for the session you're trying to decrypt, Wireshark won't be able to decrypt the traffic. You can use the display filter eapol to locate EAPOL packets in your capture. "
So if all four handshake packets are there (there are ways to help ensure you see them ;) ), you can crack WPA2 PSK, today with wireshark.
And both the PSK and "Enterprise" mode are apparently vulnerable to this: http://www.airtightnetworks.com/wpa2-hole196
So Mr "Senior Security Advisor at Sophos Canada" doesn't know what he's talking about. It's not so simple as just typing "free" (since no username is mentioned, I think he means the very broken PSK modes and not the less broken Enterprise modes).
I blame the WiFi standards bunch.
You can capture the handshake w/ WPA but not WPA2.
Or more technically sniffing the WPA2 handshake will not allow you to decrypt the traffic.
Of course TKIP is flawed and was only really included to allow backwards comptibility. WPA2 AES should be the only option.
someone sees the 'https' and thinks it's secure
Chrome does it right, with three different indicators in the URL bar: nothing for HTTP, a struck-out HTTPS for a self-signed certificate, or a plain HTTPS for a commercial certificate. But you still need an IPv4 address because downlevel clients won't send the SNI.