Secure Coding with SafeMath
Learn to use libraries like SafeMath to prevent integer overflow and underflow attacks in arithmetic operations.
The Integer Problem
In Solidity, integer types like uint256 have a fixed size. This means they can only store numbers up to a certain maximum value and down to a minimum (usually 0 for unsigned integers).
When an arithmetic operation exceeds these limits, it can lead to critical vulnerabilities called integer overflows and underflows.
Unchecked Math Dangers
Solidity's default arithmetic operations (+, -, *, /) do not automatically check for overflows or underflows. Instead, the number 'wraps around'.
This behavior can be exploited by attackers, leading to incorrect token balances, unexpected contract state, and financial losses.
All lessons in this course
- Common Vulnerabilities (Reentrancy, etc.)
- Access Control Patterns
- Secure Coding with SafeMath
- Auditing, Testing, and Bug Bounties