5 ms·

While you're correct: 1. In real life, passwords aren't random. Password manager users are probably less likely than average to make this blunder, but I'd stil

While you're correct: 1. In real life, passwords aren't random. Password manager users are probably less likely than average to make this blunder, but I'd still be willing to bet _the majority_ of lastpass's customers do. 2. Even if you personally have all random passwords, would you really want to use a product made by people who made this level of a noob mistake? I used to pay for LastPass premium, now my account is deleted, my passwords are changed, and my money goes to Bitwarden instead - and every time I hear about Lastpass I don't regret this decision.

FreakLegion 4y ago
I suspect that even non-random passwords here are fine, again practically speaking (edit: and given certain assumptions, to be clear, like no reuse), but haven't sat down and proved it. Obviously this isn't an endorsement of LastPass. Everything about their protocols is disappointing. Even if the encryption issues turn out to be of the well-that-was-a-dumb-choice-but-you-don't-need-to-panic variety, it's because they got lucky, not because they were good.
- cmeacham98 4y ago
  > and given certain assumptions, to be clear, like no reuse Maybe I wasn't obvious enough, but this is the problematic assumption. When I say "non-random password", that's what I mean: a reused password. Almost everyone I know reuses passwords (sometimes with a slight variation, but 90% of the password the same), and my day job is a software engineer. I'd be willing to be at least half of Lastpass's users have at least 1 reused password.
  - bbbbb5 4y ago
    Given that any login form can be used to rapidly confirm password reuse it's hard to see how ECB introduces new issues here.
    - tptacek 4y ago
      Attackers don't generally control the login forms, but they do have the LastPass vaults, so this response doesn't make much sense.
      - bbbbb5 4y ago
        Attacker doesn't need to control the login form to use it as an oracle to confirm password reuse.
        tptacek 4y ago
        Reuse of what? If you're assuming the attacker already has a valid password, the list of URLs they use it also irrelevant, as is the password vault. Just do what real attackers do and hit every single known login page on the Internet with it.
        bbbbb5 4y ago
        That's exactly what I'm saying :) If the attacker doesn't have the valid password, the knowledge that two different sites share the same password isn't exactly game-changing. And if the attacker does have the password, they'll figure out where it works regardless of access to LastPass db.
        tptacek 4y ago
        It's not nothing, and it's weird to be strident about it, but the obvious problem here is the offline cracking of the vault passwords; this isn't worth arguing about.
        bbbbb5 4y ago
        > It's not nothing, and it's weird to be strident about it To an outsider, hearing people talk about how LastPass used Very Bad ECB mode makes it sound like a fuckup with immediate and dramatic effect on the security of their passwords, that isn't exactly true. Nobody should have been using LastPass, but we can still be realistic about the threats facing those who did. > but the obvious problem here is the offline cracking of the vault passwords; this isn't worth arguing about. Of course not, but that's a completely separate issue from their choice of AES mode.
  - FreakLegion 4y ago
    That was a hasty edit on my way out the door this morning. Reusing a password doesn't make it easier to decrypt here, it just helps with some secondary tasks, like validating decryption output (since ECB isn't authenticated). This is rather indirect, though -- not a great example. A better example would've been the password fitting in a single block (<= 16 characters). The reason I suspect even non-random passwords might be mostly fine[1] is because there's no oracle and passwords are generally short. There's not much there for someone to hang their hat on. It's only a hunch, though; if tptacek for example says something different, I'd believe him. 1. Meaning: No need to cancel Christmas. You can deal with it later. Not meaning: ECB is as strong as CBC or whatever.
DennisP 4y ago
The whole point of a password manager is so you don't have to remember passwords. Why wouldn't you use unique random passwords? It even generates them for you.
- minusf 4y ago
  this would bite me in the worst possible moment when i need to login to somewhere and i lost my phone/battery dead/company hacked/etc. i have been using keepass(xc) since it's been around and i dont use random passwords. every year i create a formula that creates all my passwords and i put these in the vault. it also enforces password rotation. losing the vault i can still come up with any of my psswords just by remembering the formula. for company server services it's a different story, i generate wholly random strong passwords and store them in the offline vault. edit: typos
  - ilyt 4y ago
    That looks like a lot of work. I just backup the password list separately from time to time
- wpietri 4y ago
  At least in my case, the first time I used a password manager it learned my existing ones from my browser, and many of those were non-random. From that point forward I used generated passwords, but I'm sure I still have hundreds of legacy ones that I didn't bother to go and change because the sites didn't matter that much to me.
  - thechao 4y ago
    It’d be nice if, when I logged in to a site, my browser would casually mention if the pw is reused, or not. Now-a-days, I just habitually check my pw on login to make sure it’s random. For the SO & kiddos, I manually reset all the financial & identity defining pws (Google, Amazon, FB).
- taikahessu 4y ago
  If you create some new account on mobile, the workflow is messy. If you are on schedule like ordering a ticket, you just quickly try to get the job done. You need to know the specific order how to create the password for a new site. Otherwise it was just easier to plow through with your favourite memorised combination. At least I found it hard to do with Lastpass on mobile. Now I’ve tested it with Bitwarden and 1Password 8, they seem to do a better job with it.

FreakLegion 4y ago

I suspect that even non-random passwords here are fine, again practically speaking (edit: and given certain assumptions, to be clear, like no reuse), but haven't sat down and proved it. Obviously this isn't an endorsement of LastPass. Everything about their protocols is disappointing. Even if the encryption issues turn out to be of the well-that-was-a-dumb-choice-but-you-don't-need-to-panic variety, it's because they got lucky, not because they were good.

cmeacham98 4y ago
> and given certain assumptions, to be clear, like no reuse Maybe I wasn't obvious enough, but this is the problematic assumption. When I say "non-random password", that's what I mean: a reused password. Almost everyone I know reuses passwords (sometimes with a slight variation, but 90% of the password the same), and my day job is a software engineer. I'd be willing to be at least half of Lastpass's users have at least 1 reused password.
- bbbbb5 4y ago
  Given that any login form can be used to rapidly confirm password reuse it's hard to see how ECB introduces new issues here.
  - tptacek 4y ago
    Attackers don't generally control the login forms, but they do have the LastPass vaults, so this response doesn't make much sense.
    - bbbbb5 4y ago
      Attacker doesn't need to control the login form to use it as an oracle to confirm password reuse.
      - tptacek 4y ago
        Reuse of what? If you're assuming the attacker already has a valid password, the list of URLs they use it also irrelevant, as is the password vault. Just do what real attackers do and hit every single known login page on the Internet with it.
        bbbbb5 4y ago
        That's exactly what I'm saying :) If the attacker doesn't have the valid password, the knowledge that two different sites share the same password isn't exactly game-changing. And if the attacker does have the password, they'll figure out where it works regardless of access to LastPass db.
        tptacek 4y ago
        It's not nothing, and it's weird to be strident about it, but the obvious problem here is the offline cracking of the vault passwords; this isn't worth arguing about.
        bbbbb5 4y ago
        > It's not nothing, and it's weird to be strident about it To an outsider, hearing people talk about how LastPass used Very Bad ECB mode makes it sound like a fuckup with immediate and dramatic effect on the security of their passwords, that isn't exactly true. Nobody should have been using LastPass, but we can still be realistic about the threats facing those who did. > but the obvious problem here is the offline cracking of the vault passwords; this isn't worth arguing about. Of course not, but that's a completely separate issue from their choice of AES mode.
- FreakLegion 4y ago
  That was a hasty edit on my way out the door this morning. Reusing a password doesn't make it easier to decrypt here, it just helps with some secondary tasks, like validating decryption output (since ECB isn't authenticated). This is rather indirect, though -- not a great example. A better example would've been the password fitting in a single block (<= 16 characters). The reason I suspect even non-random passwords might be mostly fine[1] is because there's no oracle and passwords are generally short. There's not much there for someone to hang their hat on. It's only a hunch, though; if tptacek for example says something different, I'd believe him. 1. Meaning: No need to cancel Christmas. You can deal with it later. Not meaning: ECB is as strong as CBC or whatever.

DennisP 4y ago

The whole point of a password manager is so you don't have to remember passwords. Why wouldn't you use unique random passwords? It even generates them for you.

minusf 4y ago
this would bite me in the worst possible moment when i need to login to somewhere and i lost my phone/battery dead/company hacked/etc. i have been using keepass(xc) since it's been around and i dont use random passwords. every year i create a formula that creates all my passwords and i put these in the vault. it also enforces password rotation. losing the vault i can still come up with any of my psswords just by remembering the formula. for company server services it's a different story, i generate wholly random strong passwords and store them in the offline vault. edit: typos
- ilyt 4y ago
  That looks like a lot of work. I just backup the password list separately from time to time
wpietri 4y ago
At least in my case, the first time I used a password manager it learned my existing ones from my browser, and many of those were non-random. From that point forward I used generated passwords, but I'm sure I still have hundreds of legacy ones that I didn't bother to go and change because the sites didn't matter that much to me.
- thechao 4y ago
  It’d be nice if, when I logged in to a site, my browser would casually mention if the pw is reused, or not. Now-a-days, I just habitually check my pw on login to make sure it’s random. For the SO & kiddos, I manually reset all the financial & identity defining pws (Google, Amazon, FB).
taikahessu 4y ago
If you create some new account on mobile, the workflow is messy. If you are on schedule like ordering a ticket, you just quickly try to get the job done. You need to know the specific order how to create the password for a new site. Otherwise it was just easier to plow through with your favourite memorised combination. At least I found it hard to do with Lastpass on mobile. Now I’ve tested it with Bitwarden and 1Password 8, they seem to do a better job with it.