Facebook has patched a vulnerability that exposed page administrators. The security researcher Mohamed Based reported the flaw this week.

Baset claimed he discovered the issue, which he described as a “logical error,” within a few minutes of receiving an invitation to like a Facebook page on which he had liked a post.

The researcher looked at the email’s source-code that includes the name of the page’s administrator and other important details.

After being notified through its bug bounty program, Facebook acknowledged the vulnerability and decided to award the expert $2,500 for his findings.

Sophos’ Paul Ducklin has provided an explanation on why such an information disclosure flaw can pose a problem to Facebook page administrators.

“For many individual Facebook pages, the administrator and the page will share an identity, so putting the admin’s name in the page’s email isn’t really giving away much,” Ducklin said. “But for business or community pages, which might have a number of co-administrators, you wouldn’t expect Facebook to reveal anything more than the name of the page itself, at least not without asking.”
“If nothing else, this protects individual employees from getting bombarded with comments and questions – whether they’re praises or rants – in place of the account itself,” the expert added.

Baset, founder and lead penetration tester at Seekurity, said this was the second time he reported a vulnerability to Facebook without having to write any code to demonstrate his findings.

Facebook reported recently that last year it paid out more than $880,000 for 400 valid vulnerability reports submitted by white hat hackers.