Submission Details
Severity:
Incorrect asset handling in `_rebalanceLiquidity()`
Summary
The _rebalanceLiquidity() function attempts to deposit assets to Curve vault from LendingPool instead of RToken where assets are actually held.
Vulnerability Details
The _rebalanceLiquidity() function implementation shows incorrect asset handling.
function _rebalanceLiquidity() internal {
// if curve vault is not set, do nothing
if (address(curveVault) == address(0)) {
return;
}
uint256 totalDeposits = reserve.totalLiquidity; // Total liquidity in the system
uint256 desiredBuffer = totalDeposits.percentMul(liquidityBufferRatio);
uint256 currentBuffer = IERC20(reserve.reserveAssetAddress).balanceOf(reserve.reserveRTokenAddress);
if (currentBuffer > desiredBuffer) {
uint256 excess = currentBuffer - desiredBuffer;
// Deposit excess into the Curve vault
_depositIntoVault(excess);
} else if (currentBuffer < desiredBuffer) {
uint256 shortage = desiredBuffer - currentBuffer;
// Withdraw shortage from the Curve vault
_withdrawFromVault(shortage);
}
emit LiquidityRebalanced(currentBuffer, totalVaultDeposits);
}
During rebalance, it attempts to deposit/withdraw assets from the LendingPool.
function _depositIntoVault(uint256 amount) internal {
IERC20(reserve.reserveAssetAddress).approve(address(curveVault), amount);
curveVault.deposit(amount, address(this));
totalVaultDeposits += amount;
}
But it will revert because the reserve assets are held in the RToken contract.
Impact
The deposit and withdrawal operations to Curve vault will fail due to insufficient balance in the LendingPool contract.
Recommendations
Transfer reserve assets should be transferred from the RToken contract.
Updates
Lead Judging Commences
inallhonesty 7 months ago
Submission Judgement Published Assigned finding tags:
LendingPool::_depositIntoVault and _withdrawFromVault don't transfer tokens between RToken and LendingPool, breaking Curve vault interactions
inallhonesty 7 months ago
Submission Judgement Published Assigned finding tags:
LendingPool::_depositIntoVault and _withdrawFromVault don't transfer tokens between RToken and LendingPool, breaking Curve vault interactions
Prize pool breakdown
Total prize
77,280 USDC
nSLOC
3,86420
USDC / LOC
74,000
3,280
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