DeFi Smart Contract Vulnerabilities Audit Guide

Here are three of the most common and critical DeFi smart contract vulnerabilities, along with specific methods and tools to detect them.

1. Reentrancy Attacks

Description:

Reentrancy occurs when a contract makes an external call to an untrusted contract before updating its own state. If the external contract is malicious, it can re-enter the vulnerable function before the state update completes, allowing the attacker to drain funds multiple times. This was famously exploited in the The DAO hack (2016).

How to Detect:

• Static Analysis Tools:
  • Slither: Run slither . on your Solidity code. It specifically flags REENTRANCY warnings. Look for functions that make external calls (call, send, transfer to an address derived via tx.origin or user input) before state variable updates.
  • Mythril: Use `mythril storage-expl