DeFi Smart Contract Vulnerabilities Audit Guide

Here are three common DeFi smart contract vulnerabilities, along with specific methods to detect them:

1. Reentrancy Attacks

Description:

A reentrancy attack occurs when a contract calls an external contract (e.g., transfer() or call()) before updating its own internal state. An attacker can exploit this by making recursive calls back into the vulnerable contract before the state update completes, allowing them to drain funds multiple times.

How to Detect It:

• Static Analysis: Use tools like Slither, MythX, or Semgrep to scan for patterns where external calls (call(), transfer(), delegatecall()) occur before state variable updates (e.g., balances[msg.sender] -= amount).
• Check the "Checks-Effects-Interactions" (CEI) Pattern: Manually review code to ensure:
  1. Checks: Validate input conditions.