Higher Order

Become the owner of a contract that uses delegatecall to interact with a library or logic contract.

Vulnerable Code

Analyze the Solidity code below to find the vulnerability.

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

// Assume LibraryContract contains the logic, including setOwner
interface ILibraryContract {
    function setOwner(address _owner) external;
    // Other functions...
}

contract HigherOrderContract {
    address public owner;
    address public libraryAddress; // Address of the logic/library contract

    constructor(address _library) {
        libraryAddress = _library;
    }

    // Fallback function uses delegatecall
    fallback() external payable {
        (bool success, ) = libraryAddress.delegatecall(msg.data);
        require(success, "Delegatecall failed");
    }

    function setOwner(address _newOwner) public {
        // This function likely doesn't exist directly on HigherOrderContract
        // It must be called via the fallback -> delegatecall -> libraryAddress.setOwner
        revert("Function not implemented directly");
    }
}

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Higher Order

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