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UPEK Fingerprint Reader Software Puts Windows Passwords At Risk
colinneagle writes with this excerpt from Network World: "If your password management system is to use your 'fingerprint as your master password,' and if your laptop uses UPEK software, then you'll not be happy to know your Windows password is not secure and instead is easily crackable. In fact, 'UPEK's implementation is nothing but a big, glowing security hole compromising (and effectively destroying) the entire security model of Windows accounts.' On the Elcomsoft blog about 'advanced password cracking insight,' Olga Koksharova had bad news for people who thought they were more secure by using biometrics, a UPEK fingerprint reader, instead of relying on a password. UPEK stores Windows account passwords in the registry 'almost in plain text, barely scrambled but not encrypted.' It's not just a few that are susceptible to hacking. 'All laptops equipped with UPEK fingerprint readers and running UPEK Protector Suite are susceptible. If you ever registered your fingerprints with UPEK Protector Suite for accelerated Windows login and typed your account password there, you are at risk.'"
...I don't really know.
Using fingerprint data as an decryption key is very hard as the information is quite noisy. However, an decryption key is still needed to fetch the password (which, in turn, is needed for example to access encrypted files). Without a secure boot infrastructure a TPM doesn't help, so that leaves only the possibility of storing the key on-disk. Once the key is located, obtaining the password is trival so it doesn't really matter whether strong encryption is used.
This means that probably all fingerprint scanner software suffers from this flaw.
so how long has this been in use before somebody noticed the passwords were effectively PLAIN TEXT??
folks this is about as smart as swimming near Amnity Island with an open wound on your ankle.
I propose any kind of Silver Bullet be subjected to the Mitnick Test (throw it at a group of blackhats and then see how long it takes them to break it fix what you find and then pay them enough to keep quiet)
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As the article states, individually encrypted files using EFS would normally be secure even with the method you mention since that method does not obtain the Windows password, You can only access machine unencrypted files, or reset a password. Windows itself is as secure as you could expect. As you said the same can be done to Linux.
Still I can imagine some people think Windows machines are "secure" somehow if they just have a password on their account. These people would likely assume their system would be more secure with the UPEK reader.
Also it sounds like this UPEK software has more features, probably browser passwords and such, so there may be more problems using the UPEK software. This article doesn't state it though.
Interestingly the manufacturer is claiming passwords are stored using AES. It would be interesting to see someone else follow up and see who is telling the truth.
Remember that Simpsons ep where Smithers and Burns have to enter their top secret command post? They pass through a dozen high-tech security portals worthy of a James Bond movie to get there. Unexplained is why they didn't just use the other entrance, which consists of a broken screen door.
Then there's the ISP I used to work for that advertises "Biometric security access". What is means is that a server room in an office building has a lock that can be opened by employee fingerprint. Of course, it can also be opened by an ordinary key, which is what building security uses.
People buy security tech, and they think they've solved a security problem. Once again I quote Bruce Schneier: security is a process, not a product.
The best authentication has three components:
1. Something you know (such as a passphrase), plus...
2. Something you own (such as the ID number from a FOB which rotates IDs every minute), plus...
3. Something you are (biometrics).
You don't use biometrics *instead* of the passphrase or FOB; you use it to augment the effectiveness of those techniques.
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Ridiculously hard. Fingerprints are biometric, they change. You have a rough model that's similar to a rough model snapshot of your fingerprint pressed, squished, scanned, etc. Your print may possibly be rotated--orientation is random, but comparable to a known snapshot. Basically every time you image the fingerprint you get a slightly different result, and you apply fuzzy logic to work out if it matches prior data.
This also means that using fingerprint uniqueness points to generate some sort of AES key would store your password in plain text: the finger print is stored somewhere for verification, and therefor the finger print model can be used to derive the encryption key, and thus the key is stored with the ciphertext, thus plain text. (By this logic, if you attach your front door key to your front door with a magnet and then lock your front door and leave, your house is unlocked--any moron can pluck the key dangling by the door knob and open your door, you've simply altered the interface a bit. Key under the doormat is the same, takes a little more time examining it to figure out how you're supposed to open the door but you can, it's not really locked.)
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All consumer biometric devices should not be considered "security" devices, but rather "convenience" devices. It makes it easier to log in than typinig a password, and it's more convenient than using an OTP on the desktop. But it's not secure as a password because the password store is on the computer.
As far as password lockers go, I'm inclined to trust a password store encrypted by a passphrase (like lastpass) rather than a biometric. That's because with a passphrase, you can have a very precise method of unlocking the password store. The passphrase itself vouches for you and is repeatable. A biometric scan may vouch for you, but the values it returns are not a key. Some other key is used to decrypt the password store. And that "some other key" is open to the whims of how it's implemented by the device maker.
One caveat, on the security scale, commercial biometric devices are a different animal altogether
I always figured that the digital representation of your fingerprint would be extracted and copied. With that copy a number of options could be possible. Perhaps the scan can be bypassed entirely and the biometric computer fed the digital copy. Or perhaps the copy can be used with the reverse-algorithm from the reverse-engineered reader to produce a fingerprint that will have the same "hash value" even if it is not exactly like the owner's. Any one of these "solution" fingerprints could be printed onto paper or some material that would allow proper scanning as a normal finger.
,far easier to just read the users password out of the registry from where the biometric system wrote it.
Let us not forget the rumored "gummy bear" attack on biometric readers in the past.
But no, I guess it is far
The summary states that the passwords are scrambled but not encrypted. I fail to see the distinction. If I take a word and reverse it, that is a form of encryption. Sure, it is a very weak form, but it is.
And if you're going to just store the session key in the registry then it doesn't matter if they're using AES with a 5000-bit key.
If they used strong encryption on the password database, and then used TPM to store the session key, with a full trusted boot chain to the software needed to obtain the keys, then that would be pretty strong. However, I don't know that enough of Palladium was ever implemented to make this practical. Full-disk encryption software tends to work this way, but that runs before the bootloader, so it only needs the boot chain to be secure up to that point.
What I don't get is why it needs to store the windows account password at all. If they wrote a proper authentication plugin for the windows security model, they would just need to know the user's SID and have permission to go 'Yep, the person at the console is in fact this SID' without needed to provide the password at all. I've done this before, it's really not all that hard either, day or 2 of digging through docs and actual coding. *confused*
That's about the same as my success rate after I registered my fingerprints.
It was faster to just put my gloves on and then type my password.
Right, but they don't require a 100% match on the extracted features. Also, if the key is derived from the fingerprint, and the fingerprint template is stored on the disk, then really the key is just being stored on the disk in a roundabout way and you don't have any better security anyway.