[watevrCTF-2019]Cookie Store

[watevrCTF-2019]Cookie Store

Own 50, The cheapest 1, The second is 10, The most expensive 100 Can't afford to buy , Click the first two buy The button will deduct the corresponding money , This question should be to buy the most expensive one

bp Grab the bag , Find the most expensive , Click on buy, Found a bunch base64 Encrypted string

Decrypt and get ：

Then follow his format , Modify by yourself money by 100, then base64 encryption

 

Throw it bp in , Instead of base64 The location of the encrypted string , Pack , Return to the page and find the most expensive cookie It has been bought for us , As a gift and gave us flag：