DeFi Smart Contract Vulnerabilities Audit Guide

Here are three common DeFi smart contract vulnerabilities, along with specific detection strategies for each:

1. Reentrancy Attacks

Description:

An attacker calls a function that sends ETH or tokens to an external contract. If the external contract is malicious, it can re-enter the vulnerable function before the first call completes, potentially draining funds. This is most common in functions that follow the Check-Effects-Interactions anti-pattern (i.e., interacting with external contracts before updating internal state).

How to Detect:

• Static Analysis Tools: Use tools like Slither (by Trail of Bits) or Mythril. These tools automatically flag functions where external calls (call, send, transfer) occur before state variable updates.
  • Example Slither rule: reentrancy-eth or reentrancy-benign.
• Manual Code Review: Look for functions that: