Submitted by leastwood
The treasury manager contract holds harvested assets/COMP from Notional which are used to perform NOTE buybacks or in other areas of the protocol. The manager account is allowed to sign off-chain orders used on 0x to exchange tokens to WETH which can then be deposited in the Balancer LP and distributed to sNOTE holders.
However, _validateOrder does not validate that takerFee and makerFee are set to zero, hence, it is possible for a malicious manager to receive tokens as part of a swap, but the treasury manager contract receives zero tokens as makerFee is set to the amount the maker receives. This can be abused to effectively burn treasury tokens at no cost to the order taker.
https://github.com/0xProject/0x-monorepo/blob/0571244e9e84b9ad778bccb99b837dd6f9baaf6e/contracts/exchange/contracts/src/MixinExchangeCore.sol#L196-L250
https://github.com/0xProject/0x-monorepo/blob/0571244e9e84b9ad778bccb99b837dd6f9baaf6e/contracts/exchange-libs/contracts/src/LibFillResults.sol#L59-L91
https://github.com/code-423n4/2022-01-notional/blob/main/contracts/utils/EIP1271Wallet.sol#L147-L188
Consider checking that makerFee == 0 and takerFee == 0 in EIP1271Wallet._validateOrder s.t. the treasury manager cannot sign unfair orders which severely impact the TreasuryManager contract.
jeffywu (Notional) confirmed and commented:
pauliax (judge) commented:
