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Comment by gkoberger | Hacker News Reader

After a bit of searching, I wasn't able to find any PHP forum software that LastPass lets you log in to. I could only find one official-seeming forum, and it uses a different login. So, I think this is FUD... I don't use LastPass, but accusing them of something like this (and using the phrase "or whatever") is pretty serious without proof.

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They appear to have sunset their phpBB instance. It was the main hub and support portal on their website with up to thousands of active visitors at any given time. You can see it archived here:

https://web.archive.org/web/20150629081250/https://forums.la...

Here's the archived phpBB login page. It asks for your LastPass login and password (not your forum account, your actual LastPass login and actual LastPass master password):

https://web.archive.org/web/20150717071236/https://lastpass....

Here's a past HN discussion from the time with some guesses at how such a phpBB login using the master password could, theoretically, be implemented without knowledge of the password. Note that this doesn't imply it's possible to implement it in a way that would be resistant to their web server (running phpBB!!!!) being compromised: https://news.ycombinator.com/item?id=16016171

Thanks, that's pretty damning.

Unless I’m misremembering, the login to their general system was done by never sending the password over the wire. Instead they used js to do some sort of hashing type system locally.

But during the heartbleed attack when their systems were shown to be vulnerable, that was one of their arguments as to why it wasn’t so bad.

They pretty heavily fumbled exactly this heartbleed response too. They claimed they "weren't vulnerable" because of this setup but they clearly were. If you exfiltrated an SSL key, which heartbleed allowed, you can serve whatever JS (including JS that just explicitly exfiltrated your passphrase) you wanted to end users.

LastPass is full of clowns. There's already two examples of their cavalier approach to what should be simple security in this thread and I'm pretty sure there are more.

> Instead they used js to do some sort of hashing type system locally.

Just the other day a co-worker brought up this idea as an offhand remark. After bouncing it off those present, it took him all of twenty seconds to see why it might do harm and will do little good.

You'd think a password manager would employ some security minded people who could shoot down ideas that bad immediately.

What were the counterpoints?

A weakness in your clientside hashing will make your site weaker to brute-force attacks, since it will reduce the number of hashes (or passwords) an attacker has to try (collisions in client-side hashes will too, but very negligibly for a good hash function). It's also impossible to recover from without relying on another form of authentication to re-establish trust. For many sites this means downgrading to single-factor.

Any hash upgrade mechanism can be abused by a (possibly MITM) attacker to change a user's password while leaving you and the user none the wiser that specifically this occurred. If you need to lock someone out while their phone is beeping at them over their bank account being emptied, while not even making it look like their password was changed, that sounds like a fun way.

Lastly it's virtually the same as plaintext, since any salt will be known by even just a passive attacker. A true MITM won't even have to brute-force the hash.

Conclusion: Might do harm, will do little good.

I don't think this is accurate. It appears that the phpBB instance performs a redirect to a SAML login, meaning the login page where you're being asked for your master password is the regular login page.

Now, the fact that they have a web-based vault access requiring entry of your master password? Pretty bad, considering you can't disable it, and it's automatically activated even when just using the browser extension (at least as of a few years back, when I asked them to fix that.)

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