DeFi Smart Contract Vulnerabilities Audit Guide

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

1. Reentrancy Attacks

Description:

Reentrancy occurs when a smart contract makes an external call to another contract (or itself) before updating its own state variables (e.g., balances). If the external call triggers a callback to the original function, an attacker can re-enter the function multiple times in the same transaction, draining funds before the state is updated.

Specific Detection Methods:

• Static Analysis with Control Flow Graphs (CFG): Use tools like Slither or Mythril to identify patterns where an external call (call, delegatecall, send) occurs before a state change (e.g., balance[msg.sender] -= amount). Example Slither command: slither . --detect reentrancy-eth
• State Change Ordering Check: