challenge-6-Delegation

Ethernaut Challenge 6

In this challenge the user is provided with a contract called Delegate.sol. The goal of this challenge claim the ownership of the contract.

This challenge requires user to be familiar with the following concepts..

• Solidity delegtecall function & storage layout.
• Fallback functions.

Solution

• We can simply invoke fallback of Delegation which has the exact same storage variable layout as Delegate. It will make a delegatecall to Delegate contract which will set the owner to out address i.e msg.sender.
• This storage layout is important because whenever a delegatecall is made to another contract msg.sender & msg.value are preserved but the storage changes will be made to the contract from which th delegatecall started.
• In other word, whenever a delegatecall is made from A to function in another contract B that function behaves as it was the the part of the contract A. If any state changes are made, they are made in contract A storage.

1. Run Exploit!

forge test -vv -m test_challenge_6