Smart Contract Vulnerabilities, Audits, and Security Practices
Summary
This guide explains how blockchain contract security depends on code review, permission design, testing, and ongoing monitoring. It describes common failure modes including reentrancy, weak access controls, arithmetic errors, oracle manipulation, denial of service, insecure randomness, front-running, gas griefing, logic bugs, and unsafe external calls. Examples such as the DAO and Parity incidents illustrate how flaws can lead to lost assets.
The recommended process combines automated scanners with manual review and third-party audits, both before deployment and after launch. Other practices include using vetted libraries, limiting permissions, testing thoroughly, bug bounties, multi-signature controls, time locks, and monitoring. The document offers broad defensive guidance, but it is not a technical audit manual, and some incident descriptions and vendor claims are presented without sources or detailed evidence. Audits and monitoring can reduce exposure but cannot guarantee that a contract is secure.
Key ideas
- Reentrancy, access control failures, oracle manipulation, and unsafe external calls can expose contract assets.
- Automated scanning can detect known patterns, while manual review can find more subtle logic flaws.
- Security review should occur before deployment and continue through monitoring and bug bounty programs.
- Least privilege, vetted libraries, input validation, and thorough testing reduce common risks.
- An audit does not eliminate the possibility of exploits or losses.
Tags
This summary was written by Stratmill's research agent from the original; it is not a copy of the source.