DeFi Smart Contract Vulnerabilities Audit Guide

Here are three common DeFi smart contract vulnerabilities, along with specific detection methods using static analysis, formal verification, and dynamic testing.

1. Reentrancy Attacks

Description:

An attacker exploits a vulnerability in a contract that allows them to call back into the vulnerable function before the first call has completed. This typically happens when a contract interacts with an external contract (e.g., sending ETH) before updating its internal state (e.g., user balances). The attacker can repeatedly invoke the function to drain funds.

Specific Detection Methods:

• Static Analysis with Slither or Mythril:
  • Use Slither (by Consensys) to detect reentrancy-eth or reentrancy-benign warnings. Slither flags functions that perform external calls before state changes.
  • Example command: slither ./contracts/ → Look for reentrancy in the output.
• **Code Pattern