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DNS Flaw Hits More Than Just the Web
gringer writes "Dan Kaminsky presented at the Black Hat conference in Las Vegas on Wednesday, and said that the DNS vulnerability he discovered is much more dangerous than most have appreciated.
Besides hijacking web browsers, hackers might attack email services and spam filters, FTP, Rsync, BitTorrent, Telnet, SSH, as well as SSL services. Ultimately it's not a question of which systems can be attacked by exploiting the flaw, but rather which ones cannot. Then again, it could just be hype.
For more information, see Kaminsky's power point presentation." Update: 08/07 19:48 GMT by T : There's also an animation of the progress of the patch.
SSH will raise the key changed warning if you've connected before.
SSL will raise a certificate error unless they have some way of getting a fake cert.
You mean all the services that use DNS are at risk?!?!?!
Say it isn't so...!
Here all this time I thought the Internet WAS the Web...
its almost like every service that uses hostnames might be affected.
And they called me a fool when I refused to learn website names WHO'S LAUGHING NOW!!
If you are reading this on Slashdot, and you are just now realizing that DNS exploits affect more than just the web, then get the hell out of here. Shoo. Leave your card at the door.
Dewey, what part of this looks like authorities should be involved?
This is why I've maintained a comprehensive /etc/hosts file since 1996. Every now and then it gets to be a bit large, so I periodically print it out and cache it to a shelf full of 3-ring binders.
Virtually all bittorrent clients support a distributed hash table, and inter-client peer exchange protocol, which means that as long as you have the .torrent metafile you can bootstrap yourself into the torrent (neither DHT nor peer exchange uses DNS at all in fact, except perhaps when the client is first installed to bootstrap). The only impact would be on obtaining said .torrent file, which is explicitly out of bittorrent's problem domain.
This might surprise people relatively new to technology, but it should be obvious to anyone who's been in the field for a while.
If you can hijack DNS, you can of course replace any networked service with your own (as man-in-the-middle attack or otherwise). If you change the road signs on an intersection in the countryside, not just cars are vulnerable - all traffic is.
This would have been an interesting and informative story in the early days of Slashdot when we were all still new to the concepts of Internet. Anno 2008, I would have expected more from the editors (maybe not the new recruit, but timothy has been around for a long time). News for nerds has become news for the masses, it seems.
Maybe I should stop reading the main page and start checking only Science, Mobile and YRO.
Bad guy can force the name server to go run to the good guy and look something up It takes time to get the real request (with random number) to the good guy It takes more time to get the real response back from the good guy It takes no time for the bad guy to immediately follow up a request with a fake response Might have the wrong random number, but it'll definitely arrive first
So:
1) Bad guy pretends he's a desktop pc (Stub Resolver)
2) Bad guy as Stub Resolver asks some arbitrary name server for the target's address
2) Bad guy knows the name server will eventually ask the target
3) Bad guy spoofs the target and sends his own replies back to the name server
4) One of the bad guy's spoof replies happens to match the Transaction ID
6) Name server thinks the bad guy's reply cames from target
7) Name server thinks the target lives at the IP address in Bad Guy's spoofed reply
On google docs: http://docs.google.com/Presentation?id=dd9j7tj4_107hd7g9bfs
The three of us who still use Gopher are scared to death!
Even those who arrange and design shrubberies are under considerable economic stress at this period in history.
Its a stupid joke, alright. A no carrier signal looks nothing like when you say candlejack. We all know th
That's so last century. Here, let me fix it for you:
He who has no
I RTFA. At this point, we're hanging all of our eggs into the encyrption basket. If someone proves P=NP and breaks SSL, the whole internet is hosed. Now again, why are we telling people that this stuff is safe, when -we- know that it is not?
1. The internet will have to balkanized into those countries that have laws to go after hackers and those who do not.
2. Consumers will eventually only choose content that is actually hosted by their ISPs because that will be the only content that is safe.
3. ISPs will increasingly look to disallow traffic coming from "non-trusted" ISPs in order to protect themselves.
This is my sig.
Here we should point out that Verisign are the pig-fuckers who stopped returning NXDOMAIN for .com in favour of their own search page and should never be trusted to say anything sensible about DNS.
Well, Mr Silva, it IS a way to misdirect them to a wrong site.
"It doesn't cost enough, and it makes too much sense."
WTF? What geek or nerd would even read a PPP, much less trust anything in it?
And is it even possible to transfer actual information via Power Point? I've heard rumors that it can be done, but I don't think I've ever seen anyone actually do it.
Those who do study history are doomed to stand helplessly by while everyone else repeats it.
Kaminsky makes a point about how this bug can be used to spoof Certification Authorities who issue SSL certificates. For the cheap "domain control only validated" certificates, ownership of the domain is validated by sending an e-mail to the domain. If you can spoof DNS from the viewpoint of a CA, you can buy a valid SSL cert for a domain you don't own. Now you can spoof some banking site, and the spoofed site will properly display an SSL cert.
He also makes the point that DNS cache poisoning can be used to fake MX records in DNS, which will result in e-mail being diverted to the attacker, who can then look at it. If the attacker creates a high-priority MX record, they can read the mail, then disconnect without acknowledging receipt. The originating mailer will then resend to the next-priority MX record, the real one. So the mail reaches its destination without anything in the headers to indicate it was snooped.
To: UID 1314109
Re: CID 24512103
I, UID 84249, am laughing now.
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