Entries Tagged "Password Safe"

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Risks of Password Managers

Stuart Schechter writes about the security risks of using a password manager. It’s a good piece, and nicely discusses the trade-offs around password managers: which one to choose, which passwords to store in it, and so on.

My own Password Safe is mentioned. My particular choices about security and risk is to only store passwords on my computer — not on my phone — and not to put anything in the cloud. In my way of thinking, that reduces the risks of a password manager considerably. Yes, there are losses in convenience.

Posted on June 19, 2019 at 1:26 PMView Comments

On the Security of Password Managers

There’s new research on the security of password managers, specifically 1Password, Dashlane, KeePass, and Lastpass. This work specifically looks at password leakage on the host computer. That is, does the password manager accidentally leave plaintext copies of the password lying around memory?

All password managers we examined sufficiently secured user secrets while in a “not running” state. That is, if a password database were to be extracted from disk and if a strong master password was used, then brute forcing of a password manager would be computationally prohibitive.

Each password manager also attempted to scrub secrets from memory. But residual buffers remained that contained secrets, most likely due to memory leaks, lost memory references, or complex GUI frameworks which do not expose internal memory management mechanisms to sanitize secrets.

This was most evident in 1Password7 where secrets, including the master password and its associated secret key, were present in both a locked and unlocked state. This is in contrast to 1Password4, where at most, a single entry is exposed in a “running unlocked” state and the master password exists in memory in an obfuscated form, but is easily recoverable. If 1Password4 scrubbed the master password memory region upon successful unlocking, it would comply with all proposed security guarantees we outlined earlier.

This paper is not meant to criticize specific password manager implementations; however, it is to establish a reasonable minimum baseline which all password managers should comply with. It is evident that attempts are made to scrub and sensitive memory in all password managers. However, each password manager fails in implementing proper secrets sanitization for various reasons.

For example:

LastPass obfuscates the master password while users are typing in the entry, and when the password manager enters an unlocked state, database entries are only decrypted into memory when there is user interaction. However, ISE reported that these entries persist in memory after the software enters a locked state. It was also possible for the researchers to extract the master password and interacted-with password entries due to a memory leak.

KeePass scrubs the master password from memory and is not recoverable. However, errors in workflows permitted the researchers from extracting credential entries which have been interacted with. In the case of Windows APIs, sometimes, various memory buffers which contain decrypted entries may not be scrubbed correctly.

Whether this is a big deal or not depends on whether you consider your computer to be trusted.

Several people have emailed me to ask why my own Password Safe was not included in the evaluation, and whether it has the same vulnerabilities. My guess about the former is that Password Safe isn’t as popular as the others. (This is for two reasons: 1) I don’t publicize it very much, and 2) it doesn’t have an easy way to synchronize passwords across devices or otherwise store password data in the cloud.) As to the latter: we tried to code Password Safe not to leave plaintext passwords lying around in memory.

So, Independent Security Evaluators: take a look at Password Safe.

Also, remember the vulnerabilities found in many cloud-based password managers back in 2014?

News article. Slashdot thread.

Posted on February 25, 2019 at 6:23 AMView Comments

Passwords at the Border

The password-manager 1Password has just implemented a travel mode that tries to protect users while crossing borders. It doesn’t make much sense. To enable it, you have to create a list of passwords you feel safe traveling with, and then you can turn on the mode that only gives you access to those passwords. But since you can turn it off at will, a border official can just demand you do so. Better would be some sort of time lock where you are unable to turn it off at the border.

There are a bunch of tricks you can use to ensure that you are unable to decrypt your devices, even if someone demands that you do. Back in 2009, I described such a scheme, and mentioned some other tricks the year before. Here’s more. They work with any password manager, including my own Password Safe.

There’s a problem, though. Everything you do along these lines is problematic, because 1) you don’t want to ever lie to a customs official, and 2) any steps you take to make your data inaccessible are in themselves suspicious. Your best defense is not to have anything incriminating on your computer or in the various social media accounts you use. (This advice was given to Australian citizens by their Department of Immigration and Border Protection specifically to Muslims pilgrims returning from hajj. Bizarrely, an Australian MP complained when Muslims repeated that advice.)

The EFF has a comprehensive guide to both the tech and policy of securing your electronics for border crossings.

Posted on June 1, 2017 at 10:59 AMView Comments

Security of Password Managers

At USENIX Security this year, there were two papers studying the security of password managers:

It’s interesting work, especially because it looks at security problems in something that is supposed to improve security.

I’ve long recommended a password manager to solve the very real problem that any password that can be easily remembered is vulnerable to a dictionary attack. The world got a visceral reminder of this earlier this week, when hackers posted iCloud photos from celebrity accounts. The attack didn’t exploit a flaw in iCloud; the attack exploited weak passwords.

Security is often a trade-off with convenience, and most password managers automatically fill in passwords on browser pages. This turns out to be a difficult thing to do securely, and opens up password managers to attack.

My own password manager, Password Safe, wasn’t mentioned in either of these papers. I specifically designed it not to automatically fill. I specifically designed it to be a standalone application. The fast way to transfer a password from Password Safe to a browser page is by using the operating system’s cut and paste commands.

I still recommend using a password manager, simply because it allows you to choose longer and stronger passwords. And for the few passwords you should remember, my scheme for generating them is here.

EDITED TO ADD (9/12): The second paper was updated to include PasswordSafe. And this 2012 paper on password managers does include PasswordSafe.

Posted on September 5, 2014 at 5:18 AMView Comments

Sidebar photo of Bruce Schneier by Joe MacInnis.