Demo: Sample Scan Result

The withdraw() function sends ETH to the caller before updating the balance (CEI pattern violation). An attacker can re-enter the function via a malicious fallback and drain the contract. Vulnerable pattern detected:

function withdraw() public {
    (bool ok,) = msg.sender.call{value: balances[msg.sender]}("");
    require(ok);
    balances[msg.sender] = 0;  // ← updated AFTER external call
}

Fix (Checks-Effects-Interactions pattern):

function withdraw() public {
    uint amount = balances[msg.sender];
    balances[msg.sender] = 0;  // ← update state FIRST
    (bool ok,) = msg.sender.call{value: amount}("");
    require(ok);
}

The emergencyWithdraw() function has no onlyOwner or access modifier. Any address can drain all funds from the contract.

The return value of call() is not consistently validated across all code paths. A failed ETH transfer will silently continue execution.