Submission Details
Severity:
NFT is stuck in stability pool forever after liquidation due to no function to withdraw
Vulnerability Details
In StabilityPoolcontract, function liquidateBorrower()is called by owner/manager to finalize liquidation:
function liquidateBorrower(address userAddress) external onlyManagerOrOwner nonReentrant whenNotPaused {
_update();
// Get the user's debt from the LendingPool.
uint256 userDebt = lendingPool.getUserDebt(userAddress);
uint256 scaledUserDebt = WadRayMath.rayMul(userDebt, lendingPool.getNormalizedDebt());
if (userDebt == 0) revert InvalidAmount();
uint256 crvUSDBalance = crvUSDToken.balanceOf(address(this));
if (crvUSDBalance < scaledUserDebt) revert InsufficientBalance();
// Approve the LendingPool to transfer the debt amount
bool approveSuccess = crvUSDToken.approve(address(lendingPool), scaledUserDebt);
if (!approveSuccess) revert ApprovalFailed();
// Update lending pool state before liquidation
lendingPool.updateState();
// Call finalizeLiquidation on LendingPool
@> lendingPool.finalizeLiquidation(userAddress);
emit BorrowerLiquidated(userAddress, scaledUserDebt);
}
NFT from user that being liquidated will be transfered to stability pool:
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;
// 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));
}
But in Stability pool, there is no function to withdraw these NFT, lead to token stuck in contract forever
Impact
NFT stuck in the contract
Recommendations
Create function to withdraw these NFT.
Updates
Lead Judging Commences
inallhonesty 4 months ago
Submission Judgement Published Assigned finding tags:
Liquidated RAACNFTs are sent to the StabilityPool by LendingPool::finalizeLiquidation where they get stuck
Prize pool breakdown
Total prize
77,280 USDC
nSLOC
3,86420 USDC / LOC
74,000
3,280
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