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

What it is:

A reentrancy attack occurs when a smart contract calls an external contract (e.g., sending Ether or tokens) before updating its own internal state. The external contract can then call back into the vulnerable function before the state update is complete, allowing an attacker to repeatedly withdraw funds or manipulate state.

Specific Example:

A withdraw() function that sends ETH to a user before decrementing the user’s balance in the contract’s ledger.

How to Detect It:

• Code Pattern Analysis: Look for functions that:
  1. Interact with an external contract (e.g., call{value: amount}() or transfer()).
  2. Modify state variables after the external call.
  3. Tool: Use static analyzers