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Swiss Researchers Exploit Windows Password Flaw
Bueller_007 writes "CNET is carrying an article about a new (albeit simplistic) method used to hack alphanumeric Windows passwords in a matter of seconds, rather than minutes. To blame is a 'weakness in Microsoft's method of encoding passwords.' According to the authors, the same method, when used on Mac OS X, Unix and Linux boxes, however, could require either 4,096 times more memory or 4,096 times longer."
A few more details: Mister.de writes "As an example we have implemented an attack on MS-Windows password hashes. Using 1.4GB of data (two CD-ROMs) we can crack 99.9% of all alphanumerical passwords hashes (2 37 ) in 13.6 seconds whereas it takes 101 seconds with the current approach using distinguished points. We show that the gain could be even much higher depending on the parameters used. This was found at the
Cryptography and Security Laboratory of the Swiss Federal Institute of Technology in Lausanne (EPFL)."
People are really running out of interesting stuff to "research", aren't they...
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This is hardly a news. These weaknesses have all been known for years, and the use of dictionary attacks against passwords is very common.
Bruce Schneier talks about all of these attacks and weaknesses in his book "Applied Cryptography" which was published years ago.
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13.6 seconds or 101 seconds doesn't make much difference, now does it? The real problem is still getting administrator access to the target computer in the first place.
Cracking becomes easier if you have access to a distributed network. Parse the table into managable chunks and throw it out to 100 computers. While the time taken to crack the password might not scale down in a linear fashion [ie: time/(N computers)], it will most definately drop the crack time down to less than an hour for those computers with 12bit salts (4906*.6min= 41 hr, 41hr/100comps= 25 minutes).
Even if the 12 bit salt for mac/linux/etc was increased in size, a scale up in the number of computers used would defeat this added protection. The trend in the comp world seems to be more connectivity between large numbers of computers. All it takes is one disgruntled folding@Home grad student out at stanford to break even the most stringent password.
It seems that increasing the size of the salt would prevent the average script kiddie from breaking your password, but does nothing to alleviate the threat distributed computing presents. So what other options are there?
Now to keep it close to 13 secs, you would need 4096x more data - 1.4G x 4096 = ~5.7 Terabytes.
If you don't have any data, and have 4096 more combinations, you need to take 4096 x 1m41s ~= 4.8 days. Not quite as bad but it still looks like like we need a few more bits for the password salt...
We should just make it a 64-bit salt and not have to worry about it until Quantum computers are viable..
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Why bother cracking NT (and Win2K/XP) passwords when you can just overwrite them? Boot from this floppy and you can change any local password (including the administrator). It's been useful on more than one occasion at work...when somebody quits or is fired, I can go in and retrieve everything in just a few minutes.
That they're nearly as trivial to crack is somewhat disturbing...but given the ready availability of the password changer, it doesn't make Windows significantly less secure than it already is (hell, it can't get much less secure).
20 January 2017: the End of an Error.
I think the customers only ignore it because they've been bred on Win9x, which sort of casually asked if you felt like typing in a password, but didn't really care one way or the other if you actually did. You can't train people that passwords don't matter for 7 years and then expect them to start caring about security when you finally decide to implement it. So now we have a sea of internet users who don't know or care one whit about security all because they've been taught from the very beginning that all they ever have to do is plug it in, turn it on, and start browsing.
I strongly disagree. Maybe this 4096 times applies to the traditional single DES crypt. But execept for some rare compatibilities issues with old systems or for dumb people that create Apache .htpasswd files with it, nobody uses single DES any more for years.
Passwords hashed with MD5 and Blowfish don't have the 8 character limitation. There are still some people who like to assign users passwords like "*9_p7Z9ox" even though their system doesn't use single DES any more. This is just plenty stupid. Not only it's a hell to remember for the end user, but it's damn fast to brute force when hashes are precomputed as described in this article.
A normal password like a real sentence (ex: "I'd like to have sex with Sandra") is not only way more easy to remember, it's also orders of magnitudes harder to brute force.
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Because people consider Linux to be too obscure to be worth spending their time attacking, it rarely succumbs to such attacks.
This is just plain false. If it were true, then there would be MUCH more attacks against Apache than IIS - but the reverse is true.
Also, even if this assertion were true, can you provide references for it (as I asked in my previous post)? Let's see some posts from Linux users who think that they're immune from hack attempts because they run Linux and not windows.
And before you start yammering about Many eyes/shallow bugs or whatever, I shall use my new favorite example: the sobig worm.
First, a worm is not a hack attempt - it's malware (along with viruses.)
Second, malware such as this has little to do with obscurity - it has to do with a mindset that ignores basic security practices (namely segregation of resources.)
I see your points to some extent but consider Apache was been by far the most popular web server for at least the last 8 years running on various platforms. Security is in design and not proportional to popularity. Hack ATTEMPTS maybe be higher with popularity but those attempts are useless until you find the hole.
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I read the parent post as, "Because MS uses security through obscurity, many people think that Linux distros are inherently more secure than MS." I think he meant that security through obscurity doesn't work very well.
Building a lock that cannot be picked by a blind man is a lot easier (and less effective in the real world) than building a lock that cannot be picked by someone with the blueprints.
You grab the password hash off the network with a sniffer. Then you can work at cracking it for as long as you like.
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