Hack The Chain Learn Smart Contract Security Hands-On

An interactive training platform for Smart Contract auditing with real-world challenges. Find, exploit, and learn from vulnerabilities in a secure sandbox environment.

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

contract VulnerableVault {
    mapping(address => uint256) private balances;

    function deposit() public payable {
        balances[msg.sender] += msg.value;
    }

    function withdraw(uint256 amount) public {
        require(balances[msg.sender] >= amount);

        (bool success, ) = msg.sender.call{value: amount}("");
        require(success, "Transfer failed");

        balances[msg.sender] -= amount;
    }
}

// Can you find the vulnerability?

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