DeFi Smart Contract Vulnerabilities Audit Guide

Here are three of the most common and critical DeFi smart contract vulnerabilities, along with specific detection methods for each.

1. Reentrancy Vulnerability

Description:

Reentrancy occurs when a smart contract makes an external call to another contract (or itself) before updating its own state variables. An attacker can exploit this by calling the same function repeatedly within the external call, bypassing the state update and draining funds or duplicating rewards.

How to Detect It:

1. Static Analysis Tools:

   • Use tools like Slither (by Trail of Bits) or Mythril to scan for reentrancy patterns.
   • Look for warnings such as:

    Reentrancy in ContractName.functionName()
    External call followed by state update
   

2. Code Pattern Inspection:

   • Identify functions that:
     • Make external calls (e.g., `address.transfer