Submission Details
Severity:
Precision loss due rounding off when calculating percentages in `swan:: transferRoyalties` can lead to un expected returns
Vulnerability Details
Using x/100 when calculating royality fees and platform fees percentages in swan:: transferRoyalties leads to high precision losses and the expected amounts won't be reached since solidity rounds down.
uint256 buyerFee = (asset.price * asset.royaltyFee) / 100;
uint256 driaFee = (buyerFee * getCurrentMarketParameters().platformFee) / 100;
https://github.com/Cyfrin/2024-10-swan-dria/blob/c8686b199daadcef3161980022e12b66a5304f8e/contracts/swan/Swan.sol#L260C8-L261C87
Impact
Lower than deserved return amounts
Tools Used
Manual Review
Recommendations
Consider using 10000 for a higher precision and percentages between 0 - 10000. So that precision losses can be highly limited.
Updates
Lead Judging Commences
inallhonesty 9 months ago
Submission Judgement Published Assigned finding tags:
Rounding Issue in `Swan.sol::transferRoyalties` function
Prize pool breakdown
Total prize
21,000 USDC
nSLOC
1,03420 USDC / LOC
20,000 USDC
1,000 USDC
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