NEW YORK (AP) Face-book reported a major security breach in which 50 million user accounts were accessed by unknown attackers.
In a blog post , the company says hackers exploited a bug that affected its View As feature, which lets people see what their profiles look like to someone else. That would let attackers steal access tokens, which are digital keys that Facebook uses to keep people logged in. Possession of those tokens would allow attackers to seize control of user accounts, Facebook said.
Specifically, from the View As feature, a bug somehow allowed a video uploader to appear for sending happy birthday messages, Guy Rosen, Facebooks vice president of product management said. Another bug then created an access token that made Face-book think the hacker had legitimately signed in with the account being viewed.
We havent yet been able to determine if there was specific targeting, Rosen said in a call with reporters. It does seem broad. And we dont yet know who was behind these attacks and where they might be based.
Facebook says it has taken steps to fix the security problem and alerted law enforcement.
To deal with the issue, Face-book reset some logins, so 90 million people have been logged out and will have to log in again. That includes anyone who has been subject to a View As lookup in the past year.
Facebook says it doesnt know who is behind the attacks or where theyre based. In a call with reporters on Friday, CEO Mark Zuckerberg said that the company doesnt know yet if any of the accounts that were hacked were misused.
Jake Williams, a security expert at Rendition Infosec, said the stolen access tokens would have likely allowed attackers to view private posts and probably to post status updates or shared posts as the compromised user, but wouldnt affect passwords.
