I am not a huge fan of bug bounties since I am more of a tool developer. But as the title suggests, to keep myself fresh & bounties from IBB are special. So enter Phabricator.

Phabricator is :

• the best piece of software for collaboration
• originally written at Facebook
• now maintained by Phacility
• open source

Bugs (Great that all the details are on hackerone, no need to repeat ;)

• https://hackerone.com/reports/16315
• https://hackerone.com/reports/16392
• https://hackerone.com/reports/18691

What to grasp :

• Focus on functional bugs, there will be lots of design flaws.
• When testing something like phabricator which requires your own installation, use a VPS. Setup all the required stuff and then save a snapshot. This way even if you mess up your installation, just restore using snapshot.
• Be persistent and calm.
• Find bugs :P.

Enough of phabricator for now. Lets build some stuff ;)