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Cracking encrypted LastPass vaults

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Re: Cracking encrypted LastPass vaults

#91

Post by II2II »

poglet wrote: post #18
bedatadriven wrote: post #11

> I downloaded the popular rockyou.txt wordlist and put my actual vault master plaintext password inside Note that is NOT a demonstration of being able to crack an encrypted LastPass vault. The author's exercise wouldn't be feasible without prior knowledge of the master password, or choosing a master password that is present in a list of common passwords. That is consist with what we have heard from LastPass so far.

Agreed, it was a bit disappointing to get to the part where the password was added to the word list. The author does point out that a 2,000,000+ hashes per second could be achieved so it might give insight into how quickly all accounts will be checked against popular word lists. If I was a last pass customer I would be thinking about changing passwords on all accounts.

> Agreed, it was a bit disappointing to get to the part where the password was added to the word list.

Why is that disappointing? It is a proof of concept, rather than evidence that it has already been done. Sure, it is not novel and perhaps it is overstated, but it does point out that attacks are already possible. It would also be interesting to see the results of a dictionary attack to see if the behaviour of people who use password managers is any better than the population as a whole.

Re: Cracking encrypted LastPass vaults

#92

Post by snowwrestler »

RheingoldRiver wrote: post #7

So, if my lastpass master password is actually secure (~30 characters and contains capital, lowercase, symbols, and a long string of randomly-generated numbers that I memorized as part of it, and no part of this is reused anywhere else), do I have to worry? It does seem like a good idea to switch, but do I have to switch urgently ?

Switching to a different password manager now would do nothing to address the concern that someone has an older copy of your password database and has cracked it.

The way to address that particular concern is to change the passwords of all your services themselves. If you do that, it would a good time to change password managers too—just save the new passwords in the new manager.

Another approach would be to turn on MFA for your services, if you have not yet. Then even a cracked password will not be enough for a bad guy to get in.

All that said, if you have been using a long and complex master password, it’s unlikely that it could be successfully decrypted in the first place.

Re: Cracking encrypted LastPass vaults

#93

Post by dylan604 »

yardstick wrote: post #81
t0mas88 wrote: post #61

Earlier quoted context omitted.

So you're doing 4e10 hashes per second or 390k password guesses per second. At what price per hour?

To be fair I don’t think nation state actors care about the bill. Be it US, China, Russia, Saudi, etc.

Do you get extra credit if one of the first accounts you hack has a cloud provider account credentials that you can then spin up more machines to further the attack on someone else's dime?

Re: Cracking encrypted LastPass vaults

#94

Post by dylan604 »

lvncelot wrote: post #89
gvb wrote: post #80

Earlier quoted context omitted.

Your quote includes the most significant part of the article "and put my actual vault master plaintext password inside". He took a word list which did not include his password and put his actual password in the word list. He didn't crack his password, he showed that a brute force password guesser can find passwords that are in its word list. If he wanted to save six hours, he could have put it first in the password l…

Yes, which is why I'm so skeptical of that claim. "I've put the password in because otherwise it would've taken 6 hours" makes no sense at all - even putting aside my napkin calculation; if it would've taken an afternoon of crunching, why wouldn't you just have done that?

because 6+ hours is too hard for a 140 char limit generation of people looking to get internet traffic to a blog while the content is still fresh in people's minds posted before anyone else does it.

Re: Cracking encrypted LastPass vaults

#96

Post by ziml77 »

shrx wrote: post #17

Reminder to never use pixellation to obfuscate sensitive data: https://github.com/bishopfox/unredacter

I wish image editors would come with tools specifically for redaction. A solid colored box works but it's ugly or makes it hard to tell that there was anything written there at all.

What could be better is adding noise that matches the dominant 2 colors of the selection and focuses near areas of contrast. Then you can apply the pixellation on top of that and get something that's tougher to reverse.

Alternatively, it could try to recognize where the text and replace it with a string of random characters that are around the same size. In that case there would be absolutely no way to get back the original text since it's gone before the pixellation is even applied.

Re: Cracking encrypted LastPass vaults

#97

Post by ziml77 »

speedgoose wrote: post #84
xvector wrote: post #65

Earlier quoted context omitted.

Except using a secret key doesn't increase the day to day difficulty of using the tool. In fact, it makes it easier.

How do you store the secret key? In your head? In a physical device you must carry around?

On a printout and even inside the vault itself. You only need the key the first time you unlock the vault on a device. After that the key can be encrypted locally with just the master password or kept in the TPM (or the platform's equivalent).

Re: Cracking encrypted LastPass vaults

#98

Post by mdaniel »

nix23 wrote: post #19
xvector wrote: post #2

Good tutorial. This is why I prefer 1Password, as it requires the secret key to be compromised in addition to the Master Password, thus providing protection against a weak master password. I've always thought it foolish to recommend solutions like LastPass and BitWarden, which don't require a secret key. It is dangerous design, prioritizing ease of onboarding over actual security. The average consumer needs an autoge…

> Good tutorial. This is why I prefer 1Password, as it requires the secret key to be compromised in addition to the Master Password, thus providing protection against a weak master password. Do you know that or do you just hope they do what you think they do?

They do what any reasonable security company does, and call in vendors who have negative incentive to lie: https://support.1password.com/security-assessments/

I was especially impressed by the Cure53 ones, where they were provided access to the source code: https://bucket.agilebits.com/security/Cure53-1PW18-report.pd...

Re: Cracking encrypted LastPass vaults

#99

Post by latchkey »

t0mas88 wrote: post #48
sigmoid10 wrote: post #30

Earlier quoted context omitted.

>It's a demonstration that a laptop can reach `2,000,000+ H/s`. No, the author says their laptop only reaches ~1kH/s. That 2 million number is a pure guess for a multi-gpu setup and that is still pretty weak, unless you have a very good dictionary for a specific target. Brute forcing remotely long alphanumeric passwords is out of the question. So if you have a 8+ character password with upper+lowercase characters and…

With 8 characters, which is way below all recommendations and using only alphanumeric + the simple special chars on the keyboard you're looking at over 7 * 10^14 possibilities. If you could do 100 million hashes per second (that seems to be possible with hardware looking at crypto stuff), the way I understand the setup you're still up against the 100100 iterations in the key derivation algorithm. So that's 7 * 10^19…

I have access to 34,000+ GPUs, right now.

All that I need to do is pay for power, which is at lowest rates.

Who wants to crack some hashes?

Re: Cracking encrypted LastPass vaults

#100

Post by [deleted] »

dividedbyzero wrote: post #79
prmoustache wrote: post #59

Earlier quoted context omitted.

> Both LastPass and Bitwarden (and 1Password) support 2FA. AFAIK it doesn't help if your vault is in the hand of someone who obtained it from a security breach on lastpass/bitwarden side.

That's where 1password's security key helps because you need that for decryption. Apps will store it so you really only need it once when setting up a new phone/computer and you can transfer it from another via qr code, but if all you have is a vault dump, you're out of luck even if you phish the password (which should be easier than phishing the security key since it's used a lot and in muscle memory)

[deleted]
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