Facebook says it discovered a security breach earlier this week that affected almost 50 million accounts – out of the over two billion accounts on Facebook. The company says it has fixed the breach, which allowed hackers to take over people’s accounts.
In a statement on Friday, Facebook said that it has informed law enforcement authorities about the breach.
There was a loophole in Facebook’s code for a feature called “View As” that lets people see what their account looks like to someone else. The vulnerability allowed people to steal access tokens – digital keys that keep people logged into Facebook so they don’t need to re-enter passwords. Once logged in, the attackers could take control.
“This attack exploited the complex interaction of multiple issues in our code. It stemmed from a change we made to our video uploading feature in July 2017, which impacted ‘View As,’” Facebook said in the statement. “The attackers not only needed to find this vulnerability and use it to get an access token, they then had to pivot from that account to others to steal more tokens.”
While access codes were taken from 50 million accounts in the recent breach, Facebook said it doesn’t know whether any personal information was gathered or misused from those accounts.
Facebook users are shown the below message when they log in again:
Everyone whose profile used the “View As” tool in the last year will have to log in to Facebook again, and any apps that used Facebook to log in. From there, they’ll be able to see a statement from Facebook explaining what happened. The company estimated that about 90 million people will have to log in again.
It is unclear why 90 million people will have to log in again even though the breach impacted only 50 million.
The day the news broke, Friday, the company’s shares fell by three percent.
User data leaks, security breaches and the spread of misinformation have forced Facebook to confront hostile congressional hearings and uproar from users.
This year alone, there was the Cambridge Analytica scandal, rumors of Facebook reading personal messages, a bug affecting 14 million users, Zuckerberg’s appearance in front of the US Senate, an FTC investigation, another appearance in front of the EU officials, Sheryl Sandberg’s appearance in front of the US Senate… the list really is quite endless.
This latest breach adds to concern that Facebook is collecting too much personal information and not looking after it properly. Data is the lifeblood of its advertising business, so any limits on its activities that stem from these missteps could crimp the company’s earning power.