Facebook paid a teenage researcher from Nepal a $4,750 bug bounty reward for a vulnerability that could have been exploited to uncover the identity of a page’s administrator.
Businesses can use Facebook Pages to increase the visibility of their brand on the social media platform, but the Facebook account that has administrative rights over the page remains private.
However, 19-year-old Sudip Shah from Pokhara, Nepal, discovered that an insecure direct object reference (IDOR) vulnerability in Facebook for Android could be exploited to reveal the identity of the page admin.
When navigating to another page’s live video section in Facebook for Android, Shah discovered that changing the page_id in a request containing a vulnerable endpoint resulted in the broadcaster_id parameter in the response containing the admin ID.
“It leads to page admin disclosure which is a privacy issue to the page. The impact is high because the page’s admin information is meant to be kept private and not shown to the public,” the researcher says.
The issue only impacted pages with a live video feature enabled, but Shah estimates that most pages were affected, as most of them actually have the feature.
He also explains that, for mass exploitation, an attacker would have needed a script that could automatically change the page_id in the request and capture the broadcaster_id in the response.
Shah also published a video to demonstrate how the vulnerability could be exploited.
The researcher also discovered a variant of the security defect, where the attacker could have the admin ID leaked in the response by including a modified live_video_id in the request. The root cause of the flaw, however, was the same.
Shah reported the vulnerability to Facebook on October 5 and a patch was rolled out on October 21. Facebook told the researcher he was eligible for a $4,500 bug bounty payout. A $225 bonus was added to the reward, for a total of $4,725.
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