Wild Credit contest - gpersoon's results

Handle

gpersoon

Vulnerability details

Impact

If _timeRateToBlockRate would be called with a relative low value for _uint, a rounding error could occur. This is because _uint is divided by 365 and 86400 first and solidity doesn't have floating points. Generally its better to first multiply and then divide, unless an overflow could occur, which doesn't seem relevant here.

Proof of Concept

https://github.com/code-423n4/2021-09-wildcredit/blob/main/contracts/InterestRateModel.sol#L104 function _timeRateToBlockRate(uint _uint) private view returns(uint) { return _uint / 365 / 86400 * BLOCK_TIME / 1e18; }

Tools Used

Recommended Mitigation Steps

replace return _uint / 365 / 86400 * BLOCK_TIME / 1e18; with return _uint * BLOCK_TIME / ( 365 * 86400 * 1e18);