Unlock the vault to win the level. It’s set to locked and password protected at deployment, this is done using the bool public locked; variable and the bytes32 private password; variable, the problem is that this data is stored on chain, allowing anyone to determine what is being stored. Private data shouldn’t be stored on-chain
Vault | OpenZeppelin’s Ethernaut Level 8 Walk-Through Read More »
Level 7 of Ethernaut is Force, a lesson in self destruction. We are given this contract that contains a cat: Since the contract has no payable fallback functions we can’t send ether to the contract in the traditional ways.But the hints let us know to use another contract to attack, enter selfdestruct() Self Destruct Contracts
Force | OpenZeppelin’s Ethernaut Level 7 Walk-Through Read More »
We are given the following Solidity file that contains two contracts Delegate and Delegation. Get your new instance and open your console. According to the Solidity docs, delegatecall is similar to a call except it passes the original msg.sender and msg.value, rather than the contract making the call: There exists a special variant of a
Delegation | Ethernaut Level 6 Walk-Through Read More »
Token asks us to hack the basic token contract supplied. We start with 20 tokens and our objective is to get our hands on more. We are given a hint that an odometer might be of help so let’s start by looking it up.An odometer is the mile tracker in your car that the numbers
Token | Ethernaut Level 5 Walk-Through Read More »
Telephone asks us to claim ownership of the contract. Learn the difference between tx.origin and msg.sender. It supplies us with the following source code: The contract seems simple enough, with just one function changeOwner we can see the requirements for claiming ownership: It seems that tx.origin can not (!=) equal the msg.sender. So let’s head
Telephone | Ethernaut Level 4 Walk-Through Read More »
10 consecutive correct guesses on a coin flip? There is a tiny chance we are gonna have to work the system. We are given the source code of the contract, it tracks consecutiveWins and has a flip function that takes in a bool _guess and returns a bool for heads or tails. Let’s take a
Coin Flip | Ethernaut Level 3 Walk-Through Read More »
Fallout or FAL1OUT as the hint in the image says, has an error in the code that incorrectly implements a constructor that leads to ownership transfer by any public address interacting with a specific function. This is the first level that suggests we try Solidity’s Remix IDE, a fully web based IDE for solidity with
Fallout | OpenZeppelin Ethernaut Level 2 Walk-Through Read More »
Level 1 “Fallback” gives us the source code of a contract, to beat the level we must claim ownership of the contract and drain it’s balance to 0. Using the Get new instance button, we deploy our contract. Take a look over the Solidity smart contract code: First things first, we need to claim ownership
Fallback | OpenZeppelin Ethernaut Level 1 Walk-Through Read More »
This is the first in the Ethernaut write-up series by CAPS LOCK DAVE.LEVEL 0 CAN BE FOUND HERE This level serves as the tutorial and guides us through the setup needed to participate in the CTF. We need: Connecting our MetaMask wallet will allow us to track our progress and create a new instance of
Hello Ethernaut | OpenZeppelin Ethernaut Level 0 Walk-Through Read More »