Reddit: IDOR to pay less for coin purchases on oauth.reddit.com via /api/v2/gold/paypal/create_coin_purchase_order in `order_id` parameter

Summary: This vulnerability consist of modifying the PayPal transaction ID to buy a big coin pack but paying the small price for it. Impact: The only impact here could be that you don't earn the money you deserve, and users can offer a lot of presents to other users, breaking the magic of the...