Facebook’s hidden flaws

In Information Security ByTeam Acumin / 21st March 2012

Facebook is such a standard these days for both individuals and businesses alike it’s an unwritten rule that anyone or any company that avoids it, for whatever reason, really is living in the dark ages.

However, with the recognition that the social networking platform is an everyday thing, like perhaps the presence of mobile phones, there’s also an acknowledgement that its impact on our idea of privacy, how we interact with one another and the amount of data we upload, is yet to be fully understood. Consequently, we are open to being exploited by those whose business it is to engage in subterfuge.

Because Mark Zuckerberg’s Facebook is still fairly new – it was launched in February 2004 – and is constantly evolving, many users are, despite their ability to use it effectively and on a daily basis, still not that knowledgeable about every facet of the world’s largest social network. It’s a beast that is hard to tame.

This month, Shah Mahmood, a research student at University College London, along with Yvo Desmedt, chair of information communication technology, revealed that they had discovered a significant flaw in the system.

Speaking at the IEEE International Workshop on Security and Social Networking SESOC 2012 in Lugano, Switzerland, the pair dubbed the weakness as a “zero day privacy loophole”. Now while this appears cryptic, they did elaborate. The loophole is known as the ‘deactivated friend attack’.

“Our deactivated friend attack occurs when an attacker adds their victim on Facebook and then deactivates her own account,” the pair explained.

“As deactivation is temporary in Facebook, the attacker can reactivate her account as she pleases and repeat the process of activating and deactivating for unlimited number of times. While a friend is deactivated on Facebook, she becomes invisible. She could not be unfriended (removed from a friend’s list) or added to any specific list.”

Because Facebook users receive no notification of when friends (hackers are included in this definition) have deactivated or reactivated their accounts, they remain none the wiser as to their movements. This leaves their information open to be consumed by strangers.

“The concept of the attack is very similar to cloaking in Star Trek while its seriousness could be estimated from the fact that once the attacker is a friend of the victim, it is highly probable the attacker has indefinite access to the victim’s private information in a cloaked way,” the pair noted.

“With targeted friend requests we were able to add over 4,300 users and maintain access to their Facebook profile information for at least 261 days. No user was able to unfriend us during this time due to cloaking and short de-cloaking sessions.”