Bid Beasts
First Flight #49
Beginner FriendlyFoundrySolidityNFT
100 EXP
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Submission Details
Severity: low
Valid

Low: Incorrect event emission (“AuctionSettled” on bid)

andysakov

Low: Incorrect event emission (“AuctionSettled” on bid)

Description

  • Normal behavior: Emit BidPlaced on bids and AuctionSettled only when the auction is finalized and assets move.

  • Issue: placeBid emits AuctionSettled during bidding, which misleads indexers/analytics and can break off-chain logic.

142:147:2025-09-bid-beasts/src/BidBeastsNFTMarketPlace.sol

require(msg.sender != previousBidder, "Already highest bidder");
emit AuctionSettled(tokenId, msg.sender, listing.seller, msg.value);
// @> Root: Wrong event emitted during bid placement

Risk

Likelihood:

  • Triggers on every bid after the seller check

  • Affects all auctions

Impact:

  • Off-chain systems may believe the auction settled prematurely

  • Data integrity and user notification issues

Proof of Concept

Check the logs during any bid, as with any listeners for this event there's a wrong call to the auction settled event at bid time

// Observe logs during any bid:
// You get AuctionSettled(...) even though no sale occurred.

Recommended Mitigation

Remove the unneeded call

- emit AuctionSettled(tokenId, msg.sender, listing.seller, msg.value);
+ // keep only BidPlaced; AuctionSettled should be emitted in _executeSale
Updates

Lead Judging Commences

cryptoghost Lead Judge 3 months ago
Submission Judgement Published
Validated
Assigned finding tags:

BidBeasts Marketplace: Incorrect Event Emission

placeBid emits AuctionSettled even though the auction hasn’t ended, causing misleading event logs.

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