Core Contracts

Summary

The current check, checks if the required collateral is greater than the remaining which is correct but doesn't check if its equal.

Vulnerability Details

If the remaining collateral(collateralValue - nftValue) == the required collateral (userDebt.percentMul(liquidationThreshold)), this check will revert which is not supposed to happen.

Impact

• Undercollateralized NFTs will pass this check causing the NFT to bypass the undercollateralization

• Attacker can utilize this to withdraw their undercollateraized NFT before it is liquidated

Tools Used

manual review

Recommendations

```solidity

if (collateralValue - nftValue <= userDebt.percentMul(liquidationThreshold)) {

revert WithdrawalWouldLeaveUserUnderCollateralized();

}

````