Insecure Direct Object Reference [ IDOR ]

https://hethical.io/trello-bug-bounty-the-websocket-receives-data-when-a-public-company-creates-a-team-visible-board/

https://hackerone.com/reports/143717

https://secgeek.net/youtube-vulnerability/

https://secgeek.net/twitter-vulnerability/

https://secgeek.net/yahoo-comments-vulnerability/

http://yasserali.com/how-i-could-change-your-ebay-password/

https://duo.com/blog/duo-security-researchers-uncover-bypass-of-paypal-s-two-factor-authentication

http://www.anandpraka.sh/2014/11/hacking-facebookcomthanks-posting-on.html

https://bitquark.co.uk/blog/2016/02/09/how_i_got_access_to_millions_of_redacted_accounts

https://hackerone.com/reports/137502