Summary

When liquidate, totalCollateralToRedeem may larger than borrower collateral balance , because there is no limitation on weather totalCollateralToRedeem > borrower collateral balance

Vulnerability Details

In function liquidate, liquidator supply dsc to redeem dept, suppose a situation, liquidator want repay all dept of borrower.
And off course he will get all the collateral ,but take a look at this

Liquidator would get a bonusCollateral, and
totalCollateralToRedeem is possible > borrower total collateral ,it will fail

Impact

Dos when fully liquidate

Tools Used

manual

Recommendations

recalculate and return the unnecessary dsc to liquidator