DeFi Smart Contract Vulnerabilities Audit Guide

Here are three common DeFi smart contract vulnerabilities, along with specific detection methods:

1. Reentrancy Attack

Description:

An attacker calls an external contract (e.g., a user’s wallet or another DeFi protocol) before the state of the vulnerable contract is fully updated. If the external contract re-enters the same function, the attacker can drain funds or manipulate state variables multiple times before the initial call completes.

How to Detect:

• Static Analysis Tools: Use tools like Slither or Mythril to flag functions that perform external calls (call, delegatecall) before updating internal state variables (e.g., balances, allowances).
  • Specific Pattern: Look for functions where msg.value is received, an external call is made (e.g., recipient.transfer()), and only after that call is the balance[msg.sender] decremented.
• Code Review Checklist: