• How to Audit DeFi Smart Contracts
  • Choose the Right Target
  • Key Patterns to Check
  • Cross-Contract Analysis
  • Conclusion

§How to Audit DeFi Smart Contracts

After auditing 5 DeFi protocols, I want to share my methodology.

§Choose the Right Target

Small projects with lower bounties have higher ROI:

• StellaSwap (dollar 2,337 bounty, 34 files) = 2 Medium-High bugs found
• Stargate (dollar 10K bounty, 19 files) = 1 Medium bug found
• GMX V2 (dollar 5M bounty, 254 files, 46K lines) = 0 exploitable bugs

Big protocols have been audited many times. Small projects have lower code quality.

§Key Patterns to Check

1. Integer type choices: uint8 in loops causes permanent fund lock if array > 255
2. Access control: tx.origin vs msg.sender for keeper verification
3. Silent failures: functions that reduce output without reverting
4. Reentrancy: check CEI pattern in withdraw functions
5. Oracle manipulation: Chainlink price staleness
6. Flash loan attacks: same-block price manipulation
7. Delegatecall: storage layout collision
8. Unchecked return values: low-level call() returns

§Cross-Contract Analysis

The real bugs live in cross-contract interactions:

• How does Vault A interact with Pool B?
• What happens during partial failures?
• Are there race conditions in multi-step operations?

§Conclusion

Smart contract auditing is about pattern recognition and cross-contract analysis. The bugs that matter are rarely found by automated tools.

If you need a DeFi audit, reach out. Rates start at 0.01 BTC for a quick review.

Follow me for more security tips. Lightning address: solauditor@stacker.news