Submitted by gzeon
In OptimisticListingSeaport.rejectProposal, it reverts if proposedListing.collateral < _amount. An attacker can therefore monitor the mempool, reducing the proposedListing.collateral to _amount - 1 by frontrunning the rejectProposal call and delaying the rejection. The attacker may even be able to deny the rejection when the deadline passes.
https://github.com/code-423n4/2022-12-tessera/blob/f37a11407da2af844bbfe868e1422e3665a5f8e4/src/seaport/modules/OptimisticListingSeaport.sol#L145
https://github.com/code-423n4/2022-12-tessera/blob/f37a11407da2af844bbfe868e1422e3665a5f8e4/src/seaport/modules/OptimisticListingSeaport.sol#L153
When proposedListing.collateral < _amount, set \_amount to proposedListing.collateral and refund the excess.
stevennevins (Tessera) disagreed with severity and commented:
HickupHH3 (judge) decreased severity to Medium and commented:
