DeFi Smart Contract Vulnerabilities Audit Guide

Here are three of the most common and critical DeFi smart contract vulnerabilities, along with specific technical methods to detect them.

1. Reentrancy Attacks

Vulnerability Description:
Reentrancy occurs when a smart contract makes an external call to another contract (or its own function) before completing its state changes. An attacker can exploit this by deploying a malicious contract that, when called, recursively re-enters the vulnerable function before the original transaction finishes updating the contract’s state. This allows the attacker to drain funds multiple times.

How to Detect:

• Static Analysis for CALL before State Writes: Use tools like Slither or Mythril to identify functions where an external call (e.g., address.call{value: amount}("")) occurs before any state variable updates (e.g., balances[addr] -= amount).
  • Pattern to look for:

solidity