Locked

Unlock the contract by finding a way to modify its state despite access restrictions.

Vulnerable Code

Analyze the Solidity code below to find the vulnerability.

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

contract Locked {
    bool public unlocked = false; // slot 0

    struct NameRecord { // slot 1
        bytes32 name;
        address mappedAddress;
    }

    mapping(address => NameRecord) public registeredNameRecord; // slot 2

    // Register new name - only requirement is that it is not already registered
    function register(bytes32 _name, address _mappedAddress) public {
        // Make sure the name is not already registered
        require(registeredNameRecord[_mappedAddress].name == 0, "Name already registered");
        registeredNameRecord[_mappedAddress] = NameRecord({
            name: _name,
            mappedAddress: _mappedAddress
        });
    }

    function unlock() public {
        require(unlocked, "Contract is locked");
        // Do something after unlocking if needed
    }

    // Helper function (not part of original Ethernaut level)
    // Allows checking registration status easily
    function getRecord(address _addr) public view returns (bytes32, address) {
        return (registeredNameRecord[_addr].name, registeredNameRecord[_addr].mappedAddress);
    }
}

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Locked

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