Facebook Says it Has Discovered 'Security Issue' Affecting Nearly 50 Million Accounts, Investigation in Early Stages (fb.com)

Facebook shared the following security announcement Friday: On the afternoon of Tuesday, September 25, our engineering team discovered a security issue affecting almost 50 million accounts. We're taking this incredibly seriously and wanted to let everyone know what's happened and the immediate action we've taken to protect people's security. Our investigation is still in its early stages. But it's clear that attackers exploited a vulnerability in Facebook's code that impacted "View As", a feature that lets people see what their own profile looks like to someone else. This allowed them to steal Facebook access tokens which they could then use to take over people's accounts. Access tokens are the equivalent of digital keys that keep people logged in to Facebook so they don't need to re-enter their password every time they use the app. Here is the action we have already taken.

First, we've fixed the vulnerability and informed law enforcement. Second, we have reset the access tokens of the almost 50 million accounts we know were affected to protect their security. We're also taking the precautionary step of resetting access tokens for another 40 million accounts that have been subject to a "View As" look-up in the last year. As a result, around 90 million people will now have to log back in to Facebook, or any of their apps that use Facebook Login. After they have logged back in, people will get a notification at the top of their News Feed explaining what happened. Third, we're temporarily turning off the "View As" feature while we conduct a thorough security review. The company added it has yet to determine whether these impacted accounts were misused or any information was accessed. Senator Mark Warner has issued a stern reprimand to Facebook over the security incident revelation today. "This is another sobering indicator that Congress needs to step up and take action to protect the privacy and security of social media users. As I've said before -- the era of the Wild West in social media is over," he wrote.

Comments

Smelled this coming a mile away

[RayMarron]

And that's why the only thing you use Facebook authentication for is Facebook.

That's not what "Have to" means...

[mujadaddy]

As a result, around 90 million people will now have to log back in to Facebook

Or, y'know, they could not do that.

Aha!

[Anonymous Coward]

Is this discovery is related to the cancelation of the live deletion of Zuck's account? Talk about just in time.

Captcha: astute

Re:And they're telling users how?

[Desler]

They’re taking it seriously!! How dare you question the Zuck’s sincerity.

Security Issue internally codenamed: "Users"

[DalM]

Facebook is investigating how to patch the security vulnerability code named internally as "Users".

Limit the anonymity or it's the DEATH of truth

[shanen]

Big Subject, eh? Can I justify it?

Yeah, but I had to think for a second. The real value of this breach is that the hackers have some non-anonymous identities to abuse. If they were professional hackers, perhaps working for Russia or NK, then part of the motivation was limitations in what they can already do with fake identities (AKA sock puppets). Essentially it's a value proposition, where a real identity is much more valuable than a fake identity. It would be interesting to ask the hackers how much more valuable.

My initial reaction is that we need more data, especially about the timing. Facebook's response suggests that this attack may have begun months ago. If so, and if the hackers actually had millions of identities to play with, then we know they have been extremely careful in what they are doing with them. If they had engaged in any wholesale abuse, then Facebook would have been deluged with reports of suspicious activities.

Okay. Only more deluged than usual, but I still think it would have shown up more quickly.

But identity abuse is built on the foundation of fake identities of the anonymous stripe. I'm still advocating MEPR as the approach that could do the most to save Facebook from itself. It could even work on Slashdot, but there's no chance Slashdot could gather the resources to implement it. ADSAuPR, atAJG.

One more wrinkle from the vast world of Facebook abuse: Have the Facebook (and Twitter?) trolls started pre-blocking the people (like me) who advocate blocking trolls rather than playing with them? A block-first strategy? To evade detection or confuse the issue? It seems likely that Facebook notices accounts that get blocked too much, so perhaps the trolls have started a new rigging of the system, possibly even sharing lists of identities for mass blocking by sock puppets.

If my final speculation is approximately correct, then one of the most important forms of data the hackers could have obtained from the reported account breaches would have been the lists of blocked users. This is the kind of data that they could use quite surreptitiously to figure out (1) Who is blocking them and (2) How the blocking patterns are related to sock puppet attrition, the better to protect their hordes.