5333 private links
Last August, LastPass reported a security breach, saying that no customer information—or passwords—were compromised. Turns out the full story is worse: //
To date, we have determined that once the cloud storage access key and dual storage container decryption keys were obtained, the threat actor copied information from backup that contained basic customer account information and related metadata including company names, end-user names, billing addresses, email addresses, telephone numbers, and the IP addresses from which customers were accessing the LastPass service.
The threat actor was also able to copy a backup of customer vault data from the encrypted storage container which is stored in a proprietary binary format that contains both unencrypted data, such as website URLs, as well as fully-encrypted sensitive fields such as website usernames and passwords, secure notes, and form-filled data.
That’s bad. It’s not an epic disaster, though.
These encrypted fields remain secured with 256-bit AES encryption and can only be decrypted with a unique encryption key derived from each user’s master password using our Zero Knowledge architecture. As a reminder, the master password is never known to LastPass and is not stored or maintained by LastPass. //
John Thurston • December 26, 2022 1:31 PM
“I think the question of why everything in the credentials store was not encrypted is interesting. What possible advantage is there of not just encrypting the whole thing under your master password.”
Because this is how Lastpass is able to offer to supply uid:pwd values when you have not unlocked your vault. If this information was kept encrypted, then the browser extensions would not know when to prompt you to unlock to supply the creds.
I’ve never liked this ‘feature’, but there’s nothing I can do about it. //
Wladimir Paöant • December 27, 2022 6:56 AM
I would have been less problematic had LastPass not messed up. They:
- Failed to upgrade many accounts from 5,000 to 100,100 iterations.
- Didn’t keep up with cracking hardware improvements (100k iterations are really on the lower end today).
- Didn’t bother existing their new password complexity rules for existing accounts.
- Didn’t bother encrypting URLs despite being warned about it continuously, allowing attackers to determine which accounts are worth the effort to decrypt.
Their statement is misleading, they downplay the issues. I’ve summed it up on my blog here: https://palant.info/2022/12/26/whats-in-a-pr-statement-lastpass-breach-explained/ //
