Hands on the Ethernaut CTF

Summary: Trail of Bits walks through Zeppelin's Ethernaut Ethereum CTF, hosted on the ropsten blockchain, covering challenges on a misnamed constructor, an integer underflow, delegatecall, selfdestruct, and re-entrancy. The author was the first to finish the challenges, and the write-up notes that Slither found the same constructor-naming mistake in real contracts such as ZiberCrowdsale and PeerBudsToken.
What's compelling: The same flaws taught as puzzles - a constructor that anyone can call, an underflow that sets a balance to 2**256 - 1, and a re-entrancy pattern used in the DAO hack - have appeared in deployed contracts, and delegatecall misuse was used to steal 30M USD in the Parity Wallet hack.

Read the original at Trail of Bits Blog ↗