Security is not an afterthought in blockchain development. We have audited more than 30 smart contract codebases, and the same vulnerabilities appear repeatedly. Here are the five that cause the most damage — and how to prevent each.
1. Reentrancy
An external call lets an attacker re-enter your function before state updates finish. The fix is the checks-effects-interactions pattern and reentrancy guards.
2. Integer overflow and underflow
Arithmetic that wraps around silently corrupts balances. Modern Solidity checks this by default, but custom unchecked blocks reintroduce the risk.
3. Access control failures
Missing or wrong permission checks let anyone call privileged functions. Enforce role-based access and test every path.
4. Front-running
Public mempools let attackers order transactions to their advantage. Commit-reveal schemes and slippage limits reduce exposure.
5. Denial of service
Unbounded loops and reliance on external calls can freeze a contract. Design for gas limits and failure isolation.
An audit is cheaper than an exploit. See our blockchain development services, review the technologies we build with, or book a security review with our team.
