In the news recently has been that the Password Manager service LastPass was infiltrated and password vaults were stolen. The jist of it is that attackers were able to gain access to the company’s development environment and by extension raid a backup environment for customer password vaults.
Understandably a lot of people out there who have used LastPass will be very worried. For the IT profession there will begin questioning over how this has happened and how we should be responding when consulting. From my perspective this isn’t a post to defend LastPass, explain the attack or analyse what they should’ve done. That’s a whole separate subject matter and whilst these questions are important what I’m going into here is about the general theory of password managers, the immediate impact to users on the data loss and the potential security responses to it.
With the LastPass hack the vault that was stolen and much of the data in there was encrypted. In the December 22nd post from Karim Toubba the stolen data is described as:
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.Karim Toubba, LastPass, December 22nd 2022
The attacker was able to go and retrieve customer data pertaining to their account details such as their email address, billing address, phone numbers and IP addresses that were used to access the vault. Whilst this would appear that customers got off lightly this data is still sensitive and we’ll go into that in a bit.
Concerning the stolen vaults each one was protected with AES-256 encryption using a secret derived from the user’s master password. If users have gone with the security defaults of a 12-character password and 100,100 iterations on the Password-Based Key Derivation Function (PBKDF2) then it would take a considerable amount of processing power – potentially millions of years with the technology we currently have commercially available – to crack a properly secured vault. The attacker would have to keep hold of the trove long enough for a weakness to be found or wait enough time for the right computing power to be available and by which point the data could be useless anyway.
Based on what LastPass has said I would remain cautious but anything hyper-sensitive in the vault such as email accounts, banking or financial accounts, social media accounts and medical accounts I would instantly change as a swift precaution.
As touched on above however is that customer data was not kept encrypted. Arguably the biggest risk LastPass users now face is that the attacker has enough information to go targeted phishing against victims to either get the master password for the vault or for specific websites of interest they’ve identified.
My recommendations on password managers still stands the same and that is to combine a password manager with a separate multi-factor authentication (MFA) tool for the vault and contained logins. At the moment my favoured tools are Bitwarden combined with Yubikeys. An important note on what I’ve just said there: I do not use Bitwarden to store MFA codes. Whilst I think that it might be a good idea to add MFA codes to a vault if you for some reason have to share the account with a team on balance they really should be separate. Also a good point to make is that MFA backup codes don’t belong in the vault either.
Yes there is considerable argument that an offline password management tool like Keepass is a much safer option but that in itself brings its own problems. What happens if you lose the vault and your backup is insufficient? What happens if you can’t get to the vault in a critical moment because it’s not with you on person? What if the vault is stolen from you and you didn’t apply security practices as good as you thought? As always with security it’s a battle between doing the most secure thing and most convenient option. Personally I stick with the online option so I don’t have to worry about any of this.
In short: don’t give up on password managers. The benefits of having them far outweighs going back to a shared password for all your accounts. As long as LastPass users had a decent master password on their vault, applied MFA to sensitive accounts, changed passwords for anything hyper-sensitive and most critically watch for phishing attempts then I would hope that victims will remain safe from mass attacks.