Ethernaut Walkthroughs: level up your knowledge of Ethereum smart contract security

Openzeppelin is well-known for their battle-tested contracts we can build upon in order to create our own ERC-20 or ERC-721 tokens and more.

What they also provide is an excellent security game that teaches your the basics of smart contract security. There is no shortage of hacks resulting in millions of dollars of losses caused by insecure smart contracts. As developers, there's always something we can learn and I found the Ethernaut game to be an excellent introduction for anyone getting started with smart contract development in Solidity.

I've written down my own process and solutions to pass the Ethernaut levels. I am by no means a Solidity expert so take these posts as a starting point or inspiration to learn more about Solidity and do your own research. I suggest you look up other solutions online and compare them in order to make up your own solutions.

Here are the solutions to the levels I was able to understand and pass:

• Level 1 — Fallback
• Level 2 — Fallout
• Level 3 — Coin Flip
• Level 4 — Telephone
• Level 5 — Token
• Level 6 — Delegation
• Level 7 — Force
• Level 8 — Vault
• Level 9 — King
• Level 10 — Re-entrancy
• Level 11 — Elevator
• Level 12 — Privacy
• Level 15 — Naught Coin
• Level 16 — Preservation
• Level 17 — Recovery