Learn how Multichain was exploited, resulting in a loss of 308 ETH, worth $949,000. — TL;DR On January 18, 2022, Multichain disclosed the existence of a smart contract vulnerability, which resulted in a loss of roughly 308 ETH, worth approximately $949,000. Introduction to Multichain Multichain is an infrastructure designed to support arbitrary cross-chain interactions. Vulnerability Assessment The root cause of the exploit is a lack of input validation.