Submitted by Trust, also found by cccz
AuctionCrowdfunds bid() allows any user to compete on an auction on the partys behalf. The code in bid() forbids placing a bid if party is already winning the auction:
However, it does not account for attackers placing bids from their own wallet, and then immediately overbidding them using the partys funds. This can be used in two ways:
Parties can be stopped from buying items at a good value without any risk to the attacker.
Introduce a new option variable to AuctionCrowdfunds called speedBump. Inside the bid() function, calculate seconds since last bid, multiplied by the price change factor. This product must be smaller than the chosen speedBump. Using this scheme, the protocol would have resistance to sudden bid spikes. Optionally, allow a majority funder to override the speed bump.
merklejerk (PartyDAO) acknowledged and commented:
HardlyDifficult (judge) commented:
0xble (PartyDAO) confirmed and resolved:
