`royaltyPayment` can get to be 0

[code423n4]

Lines of code

https://github.com/rabbitholegg/quest-protocol/blob/8c4c1f71221570b14a0479c216583342bd652d8d//contracts/Erc20Quest.sol#L97 https://github.com/rabbitholegg/quest-protocol/blob/8c4c1f71221570b14a0479c216583342bd652d8d//contracts/Erc20Quest.sol#L53 https://github.com/rabbitholegg/quest-protocol/blob/8c4c1f71221570b14a0479c216583342bd652d8d//contracts/RabbitHoleTickets.sol#L113 https://github.com/rabbitholegg/quest-protocol/blob/8c4c1f71221570b14a0479c216583342bd652d8d//contracts/RabbitHoleReceipt.sol#L184

Vulnerability details

Summary

Some operations may give 0 as result due to not checks and solidity rounding

Vulnerability Detail

Assuming for example

salePrice = 100 and royaltyFee = 90, result will be 0

uint256 royaltyPayment = (salePrice_ * royaltyFee) / 10_000;

Impact

Some values are rounded down if not enough big the params

Code Snippet

• RabbitHoleReceipt.sol#L184 uint256 royaltyPayment = (salePrice_ * royaltyFee) / 10_000;

• RabbitHoleTickets.sol#L113 uint256 royaltyPayment = (salePrice_ * royaltyFee) / 10_000;

• Erc20Quest.sol#L53 return (maxTotalRewards() * questFee) / 10_000;

• Erc20Quest.sol#L97 return (receiptRedeemers() rewardAmountInWeiOrTokenId questFee) / 10_000;

Tool used

Manual analysis

Recommendation

Check that values are bigger than 10_000 before dividing it, and revert if so

[c4-judge]

kirk-baird changed the severity to QA (Quality Assurance)

[c4-sponsor]

waynehoover marked the issue as sponsor acknowledged

[kirk-baird]

Valid issue but insufficient number of issues to qualify for grade-b

[c4-judge]

kirk-baird marked the issue as grade-c