Facebook bug let websites read ‘likes’ and interests from a user’s profile

Facebook has fixed a bug that let any website pull information from a user’s profile — including their “likes” and interests — without that user’s knowledge.

That’s the findings from Ron Masas, a security researcher at Imperva, who found that Facebook search results weren’t properly protected from cross-site request forgery (CSRF) attacks, TechCrunch reports.

Masas demonstrated how a website acting in bad faith could embed an IFRAME — used to nest a webpage within a webpage — to silently collect profile information.

“This allowed information to cross over domains — essentially meaning that if a user visits a particular website, an attacker can open Facebook and can collect information about the user and their friends,” said Masas.

The malicious website could open several Facebook search queries in a new tab, and run queries that could return “yes” or “no” responses — such as if a Facebook user likes a page, for example. Masas said that the search queries could return more complex results — such as returning all a user’s friends with a particular name, a user’s posts with certain keywords and even more personal demographics — such as all of a person’s friends with a certain religion in a named city.

“The vulnerability exposed the user and their friends’ interests, even if their privacy settings were set so that interests were only visible to the user’s friends,” he said.