Submission Details
Severity:
finalizeLiquidation() never checks if debt is still unhealthy
Description
finalizeLiquidation() never checks if the debt has become healthy again just before liquidation. The borrower may not have been able to repay their debt and call closeLiquidation() but the NFT collateral's price could well have appreciated just before the call to finalizeLiquidation() and made the debt healthy again.
Impact
User's healthy loan is liquidated.
Mitigation
Add the following check:
function finalizeLiquidation(address userAddress) external nonReentrant onlyStabilityPool {
if (!isUnderLiquidation[userAddress]) revert NotUnderLiquidation();
// update state
ReserveLibrary.updateReserveState(reserve, rateData);
if (block.timestamp <= liquidationStartTime[userAddress] + liquidationGracePeriod) {
revert GracePeriodNotExpired();
}
UserData storage user = userData[userAddress];
uint256 userDebt = user.scaledDebtBalance.rayMul(reserve.usageIndex);
isUnderLiquidation[userAddress] = false;
liquidationStartTime[userAddress] = 0;
+ if (calculateHealthFactor(userAddress) < healthFactorLiquidationThreshold) {
// Transfer NFTs to Stability Pool
for (uint256 i = 0; i < user.nftTokenIds.length; i++) {
uint256 tokenId = user.nftTokenIds[i];
user.depositedNFTs[tokenId] = false;
raacNFT.transferFrom(address(this), stabilityPool, tokenId);
}
delete user.nftTokenIds;
// Burn DebtTokens from the user
(uint256 amountScaled, uint256 newTotalSupply, uint256 amountBurned, uint256 balanceIncrease) = IDebtToken(reserve.reserveDebtTokenAddress).burn(userAddress, userDebt, reserve.usageIndex);
// Transfer reserve assets from Stability Pool to cover the debt
IERC20(reserve.reserveAssetAddress).safeTransferFrom(msg.sender, reserve.reserveRTokenAddress, amountScaled);
// Update user's scaled debt balance
user.scaledDebtBalance -= amountBurned;
reserve.totalUsage = newTotalSupply;
// Update liquidity and interest rates
ReserveLibrary.updateInterestRatesAndLiquidity(reserve, rateData, amountScaled, 0);
emit LiquidationFinalized(stabilityPool, userAddress, userDebt, getUserCollateralValue(userAddress));
+ }
}
Updates
Lead Judging Commences
inallhonesty 4 months ago
Submission Judgement Published Assigned finding tags:
LendingPool::finalizeLiquidation() never checks if debt is still unhealthy
Prize pool breakdown
Total prize
77,280 USDC
nSLOC
3,86420 USDC / LOC
74,000
3,280
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