DeFi Smart Contract Vulnerabilities Audit Guide

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

1. Reentrancy Attacks

What it is:

A reentrancy vulnerability occurs when a contract makes an external call to another contract (e.g., sending ETH or ERC-20 tokens) before updating its internal state. If the external contract is malicious, it can call back into the vulnerable function before the state update completes, effectively "re-entering" the function and draining funds or altering state repeatedly.

Specific Detection Methods:

• Static Analysis Tools: Use tools like Slither or Mythril to scan for the calls → state pattern. Slither specifically flags functions that make external calls before modifying storage variables.

  slither . --filter-paths "contracts/" -v

Look for warnings like `re-entrancy-eth