✅ WARMUPS - Baking

Writeup by: @goproslowyo

Tags

• easy

Description

Author: @JohnHammond

Do you know how to make cookies? How about HTTP flavored? Press the Start button in the top-right to begin this challenge.

Writeup

This was a fun quick challenge. We want to bake “magic cookies” and it gives us a 120 hour timer. We obviously don’t want to wait that long. The app returns a base64 encoded cookie with the “cooking information”. We’ll modify it and send it back to the server:

$ echo 'eyJyZWNpcGUiOiAiTWFnaWMgQ29va2llcyIsICJ0aW1lIjogIjEwLzExLzIwMjMsIDEzOjA3OjIxIn0=' | base64 -d
{"recipe": "Magic Cookies", "time": "10/11/2023, 13:07:21"}

I changed the cookie to be 7 days into the past, 10/04/2023 and reloaded the page:

eyJyZWNpcGUiOiAiTWFnaWMgQ29va2llcyIsICJ0aW1lIjogIjEwLzQvMjAyMywgMTM6MDc6MjEifQ==

to get the flag:

flag{c36fb6ebdbc2c44e6198bf4154d94ed4}