DeFi Smart Contract Vulnerabilities Audit Guide

Here are three of the most common and damaging DeFi smart contract vulnerabilities, along with specific methods for detecting them.

1. Reentrancy

What it is:

Reentrancy occurs when a contract calls an external contract (e.g., a user’s wallet or another dApp) without first updating its internal state. The external contract can then call back into the vulnerable function before the original call completes, allowing an attacker to drain funds or manipulate state multiple times.

How to Detect It:

• Static Analysis with Slither: Use Slither (a popular Solidity static analyzer) with the reentrancy detector. It identifies functions that make external calls before state changes.

  slither . --detect reentrancy

• Manual Code Review: Look for the CEI (Checks-Effects-Interactions) pattern violation. Ensure that:
  1. Checks: Validate conditions (