LastPass Sounds Breach AlertPasswords, Reset Questions Now at Risk, Experts Warn
Warning to all LastPass users: Change your master password for the service now and ensure you're using multi-factor authentication. There has been a data breach that might allow attackers to crack master passwords and password reminders.
See Also: Rethinking Endpoint Security
"Our team discovered and blocked suspicious activity on our network," reads a security notice from Joe Siegrist, the CEO of online password management service LastPass, which allows people to store multiple passwords inside a single, cloud-based password vault.
Siegrist says the intrusion was discovered June 12. "In our investigation, we have found no evidence that encrypted user vault data was taken, nor that LastPass user accounts were accessed. The investigation has shown, however, that LastPass account email addresses, password reminders, server per user salts, and authentication hashes were compromised."
This is not the first time that LastPass has reported that passwords or data might have been hacked. In 2011, the firm reported finding a "traffic anomaly from one of our databases" that could have resulted in data exfiltration (see Passwords at Risk). In response, the firm said it took a number of steps to tighten security, including registering domains that might be used by phishing attackers, as well as removing non-core services from the LastPass network.
In the wake of this newly announced breach, Siegrist says that the company is "confident that our encryption measures are sufficient to protect the vast majority of users," noting that the site's techniques for creating users' authentication hashes - in essence, how their authentication credentials get protected - would make it very difficult for an attacker to crack those hashes "with any significant speed." But because that is a possibility, the company says it has now "locked down" all accounts, meaning that any attempt to access an account from a new device or IP address will require the user to first verify their identity via email, unless they're already using multi-factor authentication.
"We will also be prompting all users to change their master passwords," Siegrist says. "You do not need to update your master password until you see our prompt. However, if you have reused your master password on any other website, you should replace the passwords on those other websites." He adds that because encrypted user data wasn't stolen, users do not need to change the passwords for any sites stored inside their LastPass password vault.
LastPass also offers multi-factor authentication - including Google Authenticator, Yubikey and the Duo Security Authenticator - to safeguard accounts. And in the wake of the breach, multiple information security experts recommend that all LastPass users ensure that they are using this feature.
Rethink Password Reset Questions
"Should I panic because LastPass was hacked?" asks Robert David Graham, head of information security research firm Errata Security. "If you chose a long, non-dictionary password, nobody can crack it," he says, thanks to the way LastPass creates its hashing algorithms. "Conversely, if you haven't, then yes, you need to change it."
Some security experts, meanwhile, say that the biggest risk now facing LastPass users will be phishing attacks, especially because users' email addresses have been compromised. "LastPass is advising users to change the master password. While this is a good idea, it should not be the top priority," says Martin Vigo, a product security engineer for salesforce.com who's due to present the talk "Breaking Vaults: Stealing LastPass protected secrets" at the July Shakacon conference in Hawaii. "You should pay more attention to the password hint you set up and be on the lookout for any possible phishing email in the next weeks pretending to be LastPass."
Vigo says many users undercut their security by using password reminders - he recommends never using them, if possible - or else creating weak ones. "While the password reminder cannot be the password itself, it can contain it. This means that password reminders such as 'My password is correct horse battery staple' are possible," he says. "Other more common passwords reminders such as 'My dogs name' can help attackers guess your master password. Remember that they have your email, which leads to your Twitter, Facebook, etc., where possibly that information can be found."
Password Vaults: Pros and Cons
The LastPass breach begs the question of whether people should ever use password managers, a.k.a. password vaults. "If a crook gets hold of your master password, then that's like getting the crown jewels - because now the crook has access to all your accounts at once," says Paul Ducklin, a senior security adviser for anti-virus firm Sophos, in a blog post. As a result, some security experts decry their use, on the grounds that the password manager master password creates a potential single point of failure (see Malware Targets Password Managers).
But many security experts, including Bruce Schneier, have long advocated using such tools, saying that it is much more likely that users will get hacked if they reuse passwords, or select weak ones, than have their encrypted password database stolen and cracked.
F-Secure security adviser Sean Sullivan, for example, has said he "can't imagine life" without using one, because such tools can ensure that a user only uses strong passwords, and never repeats them across sites. But Sullivan also takes certain precautions, such as never entering the master password for his password manager when he's using an untrusted system - such as the shared family PC at home - in case a keylogger might be in operation.
Cloud Versus PC-Based
Users can also choose between PC-based, cloud-based or hybrid password managers. Some encryption experts, such as Johns Hopkins cryptographer Matthew Green, have voiced concerns about the security of cloud-based password management services.
Online password managers scare the crap out of me. https://t.co/U3ifwlRzzh" Matthew Green (@matthew_d_green) June 15, 2015
Runa Sandvik, a technologist at Freedom of the Press Foundation and former developer for the Tor Project, likewise notes that the LastPass breach is "a good reminder to make sure you fully understand the risks of using a cloud provider to manage passwords," but he notes that there can be upsides, too. "Do you trust yourself to make regular backups in a secure fashion if you were to store the passwords locally?" she asks. If not, then users might consider a service that has a cloud-based component, she says.
Regardless of the type of password manager used, Errata Security's Graham says it is imperative that people choose a long and strong master password. "The downside of password complexity is that you have to both remember the password and type it in frequently. There's really no getting around this - but that's what tools like LastPass or 1Password are for," he says. "They allow you to choose one strong password once, then have the system use secure random passwords for all the websites you visit. I don't use such services; I just get used to typing long strings very fast - and write down passwords - but it's a solution used by many others."