DeFi Smart Contract Vulnerabilities Audit Guide

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

1. Reentrancy Attacks

Description:

A reentrancy attack occurs when a smart contract makes an external call to another contract (or itself) before updating its internal state. This allows an attacker to re-enter the vulnerable function before the state change is committed, potentially draining funds repeatedly.

How to Detect:

• Manual Code Review: Look for the "Checks-Effects-Interactions" (CEI) pattern violation. Specifically, identify any transfer() or call() (external calls) that occur before state variable updates (e.g., balanceOf[msg.sender] -= amount).
• Static Analysis Tools: Use tools like Slither or Mythril.
  • Slither: Run slither . --detect reentrancy-eth. It flags functions where an external call