Researcher Irene Abezgauz from the Quotium Seeker Research Center discovered a Facebook flaw that allows anyone to see a profile’s private friend list.
“FBStalker reverse-engineers the Facebook Graph to find information on every user, the tool does not require a direct friendship with targeted profiles, it just needs to access to parts of victim’s posts marked as public.Through the use of Graph Search data mining activities has become very easy, Graph Search mines Facebook’s vast user data returning personalized results from natural-language queries. Using it is possible to discover what individuals like, where people have visited and if they share those same preferences with their friends.”
The study of friend list is another powerful practice to profile a target, but it is known that through privacy setting Facebook users can make the friend list public or private, if friend list is made private it will be not visible on publicly viewable profile.
The researcher demonstrated how to access to the friend list abusing the Facebook feature “People You May Know” implemented by the social networks to suggests new friends to its users.
“As part of the research for this vulnerability we wanted to verify the exact conditions under which this was possible. The friends chosen for the victim were users who also had their friends list set to private. In addition, no interactions took place between the users except for the sending of friend requests. This is data which is not publicly available to any user who is not a friend of the victim.” states the post.
FB replied that:
”If you don’t have friends on Facebook and send a friend request to someone who’s chosen to hide their complete friend list from their timeline, you may see some friend suggestions that are also friends of theirs. But you have no way of knowing if the suggestions you see represent someone’s complete friend list.”
(Security Affairs – Facebook, social network)