IDOR on deleting drafts on https://apps.topcoder.com/wiki/users/viewmydrafts.action via discardDraftId parameter

How it was found

Hi :)

On https://apps.topcoder.com/wiki/users/viewmydrafts.action, you can see your drafts, edit or delete them. Users can delete their own drafts on https://apps.topcoder.com/wiki/users/viewmydrafts.action?discardDraftId=<DRAFT_ID>. But there is no check and an attacker can change discardDraftId and delete all drafts.

Impact

An attacker can delete other user's drafts.