The $223 million attack on the Cetus Protocol exploited vulnerabilities in its Concentrated Liquidity Market Maker (CLMM) smart contracts.

Quotes that support claims

More specifically, the attack targeted Cetus' Concentrated Liquidity Market Maker (CLMM) pools using the smart contract. It involved manipulating pool prices using a flash swap, exploiting an overflow check error to inject artificially large liquidity value with a minimal amount of tokens, and then repeatedly removing liquidity to siphon assets, according to a full incident report.