DeFi Smart Contract Vulnerabilities Audit Guide

Here are three of the most common DeFi smart contract vulnerabilities, along with specific detection methods. These are based on real-world exploits (e.g., Parity, bZx, Mango Markets, Euler Finance) and industry best practices.

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1. Reentrancy

What it is:

Reentrancy occurs when a smart contract makes an external call to another contract (or itself) before completing its own state updates. If the external contract is malicious, it can re-enter the vulnerable function before the state is updated, allowing an attacker to repeatedly drain funds.

Common Variant:

• Direct Reentrancy: The attacker calls the same function repeatedly.
• Indirect Reentrancy: The attacker uses a different function in the same or another contract to exploit the unprotected state.

How to Detect It:

1. Static Analysis Tools:
   • Use tools like Slither, Mythril, or **E