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.'"

Comments

No surprise

[Anonymous Coward]

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.

Re:No surprise

[bluefoxlucid]

Basically if the fingerprint scanner integrated with Windows Login the same way as third party login systems like Novel Networks et al, it wouldn't need your password until you tried to access an encrypted file. The flaw here is they hack it out by sending your password to Windows; fingerprint data is too noisy, you compare it as "sufficiently similar" but it's going to be too unique to generate a key from with any repeatability and high entropy. Thus they store the key UUENCODED or BASE64 or MIME to obscure it, which doesn't work on hackers. Instead, they should hook the login process and directly complete user authentication without a password, and let windows ask for a password if it tries to touch an EFS file.

Re:This is a non-issue.

[The MAZZTer]

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.

Never rely on a single authentication method.

[QilessQi]

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.

Re:Never rely on a single authentication method.

[tringstad]

Biometrics are not and should not be used for authentication at all, they fall under the category of identification.

Good article on the differences between Identification, Authentication, and Authorization here:

http://technet.microsoft.com/en-us/library/cc512578.aspx

There is even a section which addresses biometrics specifically.

It's not a security device

[joeflies]

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

Well that is much simpler than I thought

[AlienSexist]

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.

Let us not forget the rumored "gummy bear" attack on biometric readers in the past.

But no, I guess it is far ,far easier to just read the users password out of the registry from where the biometric system wrote it.