challenge-21-Shop

Ethernaut Challenge 21

In this challenge the user is provided with a contract called Shop.sol. The goal of this challenge is to set the variable price to be less than 100.

Solution

• Create a contract BuyerContract.sol that has a function called price() as it is what is expected by the Shop contract.
• The price() function is called twice, at first call to price() it sets the isSold variable to our price value. We return 101 to pass the condition.
• Based on the isSold value we can on the second call to price(), return 0.

1. Run Exploit!

forge test -vv -m test_challenge_21