Smart Contract Security: Common Vulnerabilities and How to Avoid Them (Ethereum, Solana, BSC)

Smart Contract Security: Common Vulnerabilities and How to Avoid Them (Ethereum, Solana, BSC) Published by Autonix Lab — AI, Web3 & Blockchain Consulting Smart contracts are immutable by design. Once deployed, a bug isn't a patch away — it's a potential nine-figure exploit waiting to happen. The history of DeFi is littered with protocols that passed audits, raised millions, and still got drained because of a single overlooked edge case. This article walks through the most dangerous vulnerability classes across Ethereum/Solidity, Solana/Rust, and BNB Smart Chain — with concrete examples and practical mitigation patterns for each. Ethereum & Solidity Ethereum has the oldest and most battle-tested smart contract ecosystem, which means it also has the longest list of documented exploits. 1. Reentrancy The classic. The DAO hack in 2016 — $60M drained. Still happening today. The problem: A contract sends ETH to an external address before updating its internal state. The recipient's f