The sellTokenForLRC function in the vault protocol in the smart contract implementation for Loopring (LRC), an Ethereum token, lacks access control for fee swapping and thus allows price manipulation.
https://etherscan.io/address/0x4b89f8996892d137c3de1312d1dd4e4f4ffca171
https://blocksecteam.medium.com/loopring-lrc-protocol-incident-66e9470bd51f