DeFi Smart Contract Vulnerabilities Audit Guide

Here are three common DeFi smart contract vulnerabilities, along with specific detection methods using static analysis tools, fuzzing, and manual code review patterns.

1. Reentrancy

Description:

Reentrancy occurs when a contract calls an external contract (e.g., sending ETH via call) before updating its internal state. If the external contract is malicious, it can re-enter the vulnerable function before the state change is complete, allowing an attacker to drain funds.

Specific Detection Methods:

• Static Analysis (Slither): Use Slither (a popular Solidity static analyzer) with the reentrancy detector. Look for warnings like:

  [REENTRANCY] (Impact: High)
  Contract [MyToken] inherits from [ReentrancyGuard] but does not use it.
  Function [withdraw()] has external calls before state updates.

Key pattern to check