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Bitwarden PINs can be brute-forced

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Re: Bitwarden PINs can be brute-forced

#271

Post by jve »

munchbunny wrote: post #263
jve wrote: post #249

Earlier quoted context omitted.

> since the keylogger isn’t going to be able to steal your private key off the hardware token, unlike for TOTP How? I mean how can keylogger get the secret from which TOTPs are being generated? And why wouldn't some other malware won't be able to read whatever data hardware token inputs? I'm myself yubikey user and would like to know in what ways it is more secure than TOTP, even in the scenario when my workstation g…

> How? I mean how can keylogger get the secret from which TOTPs are being generated? Since it’s time based with a 30 second window, you don’t need to know the secret, you just need to be able to repeat the code as it is typed. It takes more effort because it has to be done in real time, but 30-ish seconds is pretty doable. > And why wouldn't some other malware won't be able to read whatever data hardware token inputs…

I see private key within Yubikey the same as TOTP secret. Ok, for TOTP it is stored on host, but as you said: "you don’t need to know the secret"

When I press button on yubikey, it pastes some jibberish - way more than 6 chars, but can't THAT token be re-used?

Okay, browsers have some integrations with this stuff so it is not always some kind of a web form where that goes into, so could be a bit more secure.

I'm no security expert, I'm just thinking out loud and hoping someone educate me :)

Yeah, the end result (whatever header value or cookie in browser) is still readable by malware.

Re: Bitwarden PINs can be brute-forced

#272

Post by munchbunny »

jve wrote: post #271
munchbunny wrote: post #263

Earlier quoted context omitted.

> How? I mean how can keylogger get the secret from which TOTPs are being generated? Since it’s time based with a 30 second window, you don’t need to know the secret, you just need to be able to repeat the code as it is typed. It takes more effort because it has to be done in real time, but 30-ish seconds is pretty doable. > And why wouldn't some other malware won't be able to read whatever data hardware token inputs…

I see private key within Yubikey the same as TOTP secret. Ok, for TOTP it is stored on host, but as you said: "you don’t need to know the secret" When I press button on yubikey, it pastes some jibberish - way more than 6 chars, but can't THAT token be re-used? Okay, browsers have some integrations with this stuff so it is not always some kind of a web form where that goes into, so could be a bit more secure. I'm no s…

> When I press button on yubikey, it pastes some jibberish - way more than 6 chars, but can't THAT token be re-used?

Just to be clear, that's not related to FIDO which I was originally talking about. That's one of the extra OTP features that most Yubikeys come with, but it's unrelated to the Yubikey's FIDO capability.

Re: Bitwarden PINs can be brute-forced

#273

Post by Wowfunhappy »

noname120 wrote: post #257
Wowfunhappy wrote: post #15

Earlier quoted context omitted.

Okay, but my laptop doesn't have that either.

Buy a U2F USB key.

I would loose that, unless I kept it permanently in my laptop's USB port, in which case it would use up a USB port.

I think the system I suggested above would work a lot better. What I have now isn't so bad as my passcode is moderately strong, it just could be better.

Re: Bitwarden PINs can be brute-forced

#274

Post by Takennickname »

ddulaney wrote: post #198
ar9av wrote: post #192

Earlier quoted context omitted.

Bitwarden argues that the finding is out of scope because from what I can gather the claim that exploiting this requires access to the device. If that were the case, I'd agree with them. But having access to the Bitwarden database is not the same as having access to the device. There are plenty of vulnerabilities that give you limited read access. Simply selling your hard drive without erasing the data first would be…

I really like the way 1Password and MacOS work together for security [0]. Even if my laptop is unlocked, each 1Password interaction needs my fingerprint. That unlocks a secret stored in the Secure Enclave, which I trust. (Security is hard and flaws are possible, but Apple has done a reasonably good job here from what I can tell.) I only have to mess around with typing a long string of nonsense in when I'm registering…

Fingerprinting and everything work perfectly fine on Fedora with the ThinkPad's built in fingerprint scanner.

Re: Bitwarden PINs can be brute-forced

#275

Post by eviks »

lxgr wrote: post #262
eviks wrote: post #154

Earlier quoted context omitted.

It's not too small, your not limited to just numbers in your PIN on a computer

A PIN is, if not by definition then by practical user experience, a short, numeric secret. You really can‘t blame users for using one for a field that purports to ask for a PIN.

Except this thread isn't about blaming the users, but assessing the potential for improvement, where this simple mistake leads to inaction So yeah, they should change the stupid name and be more clear that users should use letters as well, but it's still valuable to increase argon work factor parameters

Re: Bitwarden PINs can be brute-forced

#276

Post by lxgr »

eviks wrote: post #275
lxgr wrote: post #262

Earlier quoted context omitted.

A PIN is, if not by definition then by practical user experience, a short, numeric secret. You really can‘t blame users for using one for a field that purports to ask for a PIN.

Except this thread isn't about blaming the users, but assessing the potential for improvement, where this simple mistake leads to inaction So yeah, they should change the stupid name and be more clear that users should use letters as well, but it's still valuable to increase argon work factor parameters

If you call something a PIN, salted hashing is completely pointless (and software still doing it tells me that the vendor hasn't grasped this fact).

A Personal Identification Number typically has 10k (or less frequently a million) possible values. Hashing buys you a few seconds of brute force resistance here at most, which is completely useless.

If you dial up the hashing complexity enough to make a dent, even legitimate logins will start having an unacceptable UX and battery life impact. You're just on the wrong side of the e function with PINs.

> be more clear that users should use letters as well

The entire point of the feature is that the PIN, whether letters or numbers, is shorter and/or easier to type than your passphrase. If you require users to use something of equivalent security to their passphrase, you might as well remove the feature.

Re: Bitwarden PINs can be brute-forced

#277

Post by andrewaylett »

lxgr wrote: post #269
andrewaylett wrote: post #219

Earlier quoted context omitted.

Bitwarden's fingerprint integration does exactly the same.

Given that, really the only thing that Bitwarden would have needed to do is to clearly label the PIN feature as being much less secure than the biometry option, especially when used in combination with the "do not ask for passphrase after browser restarts" option, which persists an only PIN-encrypted version of the master encryption key to disk.

Agreed -- I happily use biometric unlock, but there's no way I'd turn on PIN unlock.

Re: Bitwarden PINs can be brute-forced

#278

Post by lxgr »

Takennickname wrote: post #274
ddulaney wrote: post #198

Earlier quoted context omitted.

I really like the way 1Password and MacOS work together for security [0]. Even if my laptop is unlocked, each 1Password interaction needs my fingerprint. That unlocks a secret stored in the Secure Enclave, which I trust. (Security is hard and flaws are possible, but Apple has done a reasonably good job here from what I can tell.) I only have to mess around with typing a long string of nonsense in when I'm registering…

Fingerprinting and everything work perfectly fine on Fedora with the ThinkPad's built in fingerprint scanner.

Interesting, how can fingerprints be used as a cryptographic unlocking method on Linux? Does this involve the TPM somehow, or does the security model assume a non-compromised userspace and/or kernel?

Re: Bitwarden PINs can be brute-forced

#279

Post by eviks »

lxgr wrote: post #276
eviks wrote: post #275

Earlier quoted context omitted.

Except this thread isn't about blaming the users, but assessing the potential for improvement, where this simple mistake leads to inaction So yeah, they should change the stupid name and be more clear that users should use letters as well, but it's still valuable to increase argon work factor parameters

If you call something a PIN, salted hashing is completely pointless (and software still doing it tells me that the vendor hasn't grasped this fact). A Personal Identification Number typically has 10k (or less frequently a million) possible values. Hashing buys you a few seconds of brute force resistance here at most, which is completely useless. If you dial up the hashing complexity enough to make a dent, even legiti…

I don't know why your repeat the same mistake with 10k, "typical" doesn't mean you ignore the atypical, that's still a net benefit.

Your last point is also misleading - no, you don't require the equivalent to master password, and yes, it still makes sense in that case. "Shorter/easier" can still mean enough entropy for the smaller threat model of local compromise (with even more entropy required in the master password for the bigger threat of cloud compromise). It's when it drops down to the level of literal 4-number PIN, then it becomes useless against this threat and only useful for an even smaller threat

Re: Bitwarden PINs can be brute-forced

#280

Post by SiempreViernes »

lxgr wrote: post #267
SiempreViernes wrote: post #266

Earlier quoted context omitted.

If you don't even have a screen lock on your laptop, what business do you have complaining that bitwarden didn't protect your secrets? And it's not like there is much reason for any extra effort either, because that user will for sure be logged in to the webmail that they use for mail-2fa so all logins can be password reset anyway.

Don't worry about me, I do have a screen lock. Still, I think that software in general, and security software in particular, should follow the principle of least surprise. In the case of PINs, this is, in my view, an implicit contract to rate-limit invalid PIN attempts somewhere , regardless of all other security measures.

Sorry if it came across as a statement directed at you as a person lxgr, I was using "you" in the generalised sense:

> We can use one, you or we when we are making generalisations and not referring to any one person in particular. When used like this, one, you and we can include the speaker or writer

https://dictionary.cambridge.org/grammar/british-grammar/pro...

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