DeFi Smart Contract Vulnerabilities Audit Guide

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

1. Reentrancy Attacks

What it is:

Reentrancy occurs when a smart contract makes an external call to another contract (or itself) before finishing its state changes. An attacker can exploit this by deploying a malicious contract that recursively calls the vulnerable function before the original state update (e.g., balance deduction) is completed. This allows the attacker to drain funds multiple times.

How to Detect It:

• Static Analysis: Use tools like Slither, Mythril, or Securify to identify functions that make external calls (call, delegatecall, staticcall) before updating state variables. Look for patterns where require checks or balance updates happen after external calls.
• Code Pattern Review: Manually inspect functions that transfer ETH or tokens. Check if the order follows the