Sample Audit service

prem yekkali

Auditor

Blockchain Developer

Security Engineer

Ethereum

Remix IDE

Truffle

This project provides a comprehensive audit of a sample smart contract, showcasing the audit service's effectiveness in identifying vulnerabilities and enhancing security. The audit will deliver a thorough evaluation, focusing on the contract's integrity, performance, and compliance with best practices.

Sample Smart Contract Code for demonstrating audit process

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

contract SampleERC20Token {
    string public name = "SampleToken";
    string public symbol = "STK";
    uint8 public decimals = 18;
    uint256 public totalSupply;

    mapping(address => uint256) public balances;
    mapping(address => mapping(address => uint256)) public allowed;

    event Transfer(address indexed from, address indexed to, uint256 value);
    event Approval(address indexed owner, address indexed spender, uint256 value);

    function transfer(address recipient, uint256 amount) public returns (bool) {
        require(amount <= balances[msg.sender], "Insufficient balance");
        balances[msg.sender] -= amount;
        balances[recipient] += amount;
        emit Transfer(msg.sender, recipient, amount);
        return true;
    }

    function approve(address spender, uint256 amount) public returns (bool) {
        allowed[msg.sender][spender] = amount;
        emit Approval(msg.sender, spender, amount);
        return true;
    }

    function transferFrom(address sender, address recipient, uint256 amount) public returns (bool) {
        require(amount <= balances[sender], "Insufficient balance");
        require(amount <= allowed[sender][msg.sender], "Allowance exceeded");
        balances[sender] -= amount;
        balances[recipient] += amount;
        allowed[sender][msg.sender] -= amount;
        emit Transfer(sender, recipient, amount);
        return true;
    }

    function mint(address account, uint256 amount) public {
        totalSupply += amount;
        balances[account] += amount;
        emit Transfer(address(0), account, amount);
    }

    function burn(uint256 amount) public {
        require(amount <= balances[msg.sender], "Insufficient balance");
        balances[msg.sender] -= amount;
        totalSupply -= amount;
        emit Transfer(msg.sender, address(0), amount);
    }
}

Summary

This report outlines the findings from the audit of the SampleERC20Token contract, focusing on identifying vulnerabilities, risks, and areas for improvement.

1) Comprehensive Audit Report

Critical Issues

Minting Without Access Control

Description: The mint function can be called by anyone, allowing for unlimited token creation.

Remediation Guidance:

Step 1: Import the OpenZeppelin Ownable contract.

Step 2: Inherit from Ownable in your contract.

Step 3: Modify the mint function to include the onlyOwner modifier.

import "@openzeppelin/contracts/access/Ownable.sol";

contract SampleERC20Token is Ownable {
    ...
    function mint(address account, uint256 amount) public onlyOwner {
        totalSupply += amount;
        balances[account] += amount;
        emit Transfer(address(0), account, amount);
    }
}

Major Issues

Burning Without Access Control

Description: The burn function can be called by anyone, allowing anyone to destroy tokens from any account.

Remediation Guidance:

Step 1: Modify the burn function to include the onlyOwner modifier.

function burn(uint256 amount) public onlyOwner {
    require(amount <= balances[msg.sender], "Insufficient balance");
    balances[msg.sender] -= amount;
    totalSupply -= amount;
    emit Transfer(msg.sender, address(0), amount);
}

2. Lack of Pausable Functionality

Description: The contract cannot be paused in emergencies.

Remediation Guidance:

Step 1: Import the OpenZeppelin Pausable contract.

Step 2: Inherit from Pausable in your contract.

Step 3: Implement pause and unpause functions.

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

contract SampleERC20Token is Pausable {
    ...
    function pause() public onlyOwner {
        _pause();
    }
    function unpause() public onlyOwner {
        _unpause();
    }
}

Minor Issues

Reentrancy Risk in Transfer Functions

Description: Potential for reentrancy attacks since state changes occur after the token transfer.

Remediation Guidance:

Step 1: Import OpenZeppelin's ReentrancyGuard.

Step 2: Inherit from ReentrancyGuard in your contract.

Step 3: Add the nonReentrant modifier to the transfer and transferFrom functions.

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

contract SampleERC20Token is ReentrancyGuard {
    ...
    function transfer(address recipient, uint256 amount) public nonReentrant returns (bool) {
        require(amount <= balances[msg.sender], "Insufficient balance");
        balances[msg.sender] -= amount;
        balances[recipient] += amount;
        emit Transfer(msg.sender, recipient, amount);
        return true;
    }
    ...
}

Notes

Code Quality and Best Practices

Description: Overall code quality is acceptable, but adding more comments could enhance clarity.

Remediation Guidance:

Step 1: Review the code to ensure complex logic has adequate comments.

Step 2: Maintain consistent naming conventions and consider adding documentation for public functions.

Use of SafeMath

Description: While Solidity 0.8.0 includes built-in overflow checks, consider documenting this for clarity.

Remediation Guidance:

Step 1: Ensure that developers understand the implications of using Solidity 0.8.0.

Step 2: Consider using SafeMath for educational purposes, even though it's not necessary in this version.

Final Conclusion

The audit of the SampleERC20Token contract identified several critical and major issues that need to be addressed to ensure the security and robustness of the token implementation. The primary concerns revolve around access control for minting and burning functions, potential vulnerabilities to reentrancy attacks, and the absence of a pausable mechanism.

By following the remediation guidance provided, these issues can be resolved, significantly enhancing the contract's security posture. Additionally, maintaining high code quality and adherence to best practices is essential for the long-term viability of the project.

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Posted Oct 25, 2024

The SampleERC20Token audit showcases smart contract security by identifying vulnerabilities, illustrating best practices, and providing remediation guidance.

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Sample Audit service

Sample Smart Contract Code for demonstrating audit process

Summary

1) Comprehensive Audit Report

Critical Issues

Major Issues

Minor Issues

Notes

Final Conclusion

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