DeFi Smart Contract Vulnerabilities Audit Guide

Here are three common DeFi smart contract vulnerabilities, along with specific detection methods using static analysis, dynamic testing, and manual review techniques.

1. Reentrancy Attacks

Description:

Reentrancy occurs when a smart contract makes an external call (e.g., sending ETH or tokens) before updating its internal state. An attacker can exploit this by deploying a malicious contract that, upon receiving the call, re-enters the vulnerable function before the state has been updated, allowing them to drain funds repeatedly.

Specific Detection Methods:

• Static Analysis with Slither/Oyente:
  • Use tools like Slither (from Cyfrin) to detect reentrancy-eth and reentrancy-no-eth warnings.
  • Look for patterns where an external call (address.payable(to).call{value: amount}("")) occurs before a state variable update (e.g., `balances[msg.sender] -=