Submission Details
Severity:
Auctions can be gamed
Summary
Auctions can be exploited by a large deposit near the end.
Vulnerability Details
Like other auctions, DaiGoldAuction can be gamed by a single large deposit just before the end.
function bid(uint256 amount) external virtual override onlyWhenLive {
if (amount == 0) { revert CommonEventsAndErrors.ExpectedNonZero(); }
bidToken.safeTransferFrom(msg.sender, treasury, amount);
uint256 epochIdCache = _currentEpochId;
depositors[msg.sender][epochIdCache] += amount;
This is done in order for the big depositor to gets his "fixed" token price, where before his bid he can calculate at what price he would get the tokens and decide if it's worth making the bid and if yes - how much should he bid.
Impact
Auctions can be manipulated.
Tools Used
Manual review.
Recommendations
Given the current implementation, I can't recommend an easy fix for this issue.
Updates
Prize pool breakdown
Total prize
25,000 USDC
nSLOC
99825 USDC / LOC
20,000 USDC
2,500 USDC
2,500 USDC
Live
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