1. Bridge.sol

• Summary: The Bridge.sol contract has been analyzed for common Solidity vulnerabilities. The analysis identified a reentrancy risk due to an external call and an unchecked arithmetic operation that could lead to an underflow.

• Vulnerability Details:

  • Reentrancy Risk: SWC-107: External call may lead to reentrancy.

    (bool success, ) = targetContract.call{value: amount}(data);

    Line: 45

  • Unchecked Arithmetic: SWC-101: Subtraction may cause underflow.

    uint256 newBalance = currentBalance - withdrawalAmount;

    Line: 60

• Impact: Could lead to unauthorized fund transfers or incorrect balances.

• Tools Used: Manual code inspection.

• Recommendations:

  • Reentrancy Fix: Implement ReentrancyGuard to protect external calls.

    import "@openzeppelin/contracts/security/ReentrancyGuard.sol";

  • Arithmetic Fix: Use Solidity 0.8+ built-in overflow/underflow protection.

    uint256 newBalance = SafeMath.sub(currentBalance, withdrawalAmount);