Submission Details
Severity:
No check if Arbitrum L2 sequencer is down in Chainlink feeds
Summary
Using Chainlink in L2 chains such as Arbitrum requires to check if the sequencer is down to avoid prices from looking like they are fresh although they are not.
Vulnerability Details
In 'distributeAssets' function there is no check if the sequencer is down:
function distributeAssets(ILiquidationPoolManager.Asset[] memory _assets, uint256 _collateralRate, uint256 _hundredPC) external payable {
consolidatePendingStakes();
(,int256 priceEurUsd,,,) = Chainlink.AggregatorV3Interface(eurUsd).latestRoundData();
uint256 stakeTotal = getStakeTotal();
uint256 burnEuros;
uint256 nativePurchased;
for (uint256 j = 0; j < holders.length; j++) {
Position memory _position = positions[holders[j]];
uint256 _positionStake = stake(_position);
if (_positionStake > 0) {
for (uint256 i = 0; i < _assets.length; i++) {
ILiquidationPoolManager.Asset memory asset = _assets[i];
if (asset.amount > 0) {
(,int256 assetPriceUsd,,,) = Chainlink.AggregatorV3Interface(asset.token.clAddr).latestRoundData();
uint256 _portion = asset.amount * _positionStake / stakeTotal;
uint256 costInEuros = _portion * 10 ** (18 - asset.token.dec) * uint256(assetPriceUsd) / uint256(priceEurUsd)
* _hundredPC / _collateralRate;
if (costInEuros > _position.EUROs) {
_portion = _portion * _position.EUROs / costInEuros;
costInEuros = _position.EUROs;
}
_position.EUROs -= costInEuros;
rewards[abi.encodePacked(_position.holder, asset.token.symbol)] += _portion;
burnEuros += costInEuros;
if (asset.token.addr == address(0)) {
nativePurchased += _portion;
} else {
IERC20(asset.token.addr).safeTransferFrom(manager, address(this), _portion);
}
}
}
}
positions[holders[j]] = _position;
}
if (burnEuros > 0) IEUROs(EUROs).burn(address(this), burnEuros);
returnUnpurchasedNative(_assets, nativePurchased);
}
Impact
If the Arbitrum sequencer goes down, the protocol will allow users to continue to operate at the previous (stale) rates.
Tools Used
Manual Review
Recommendations
Add the following checks
function distributeAssets(ILiquidationPoolManager.Asset[] memory _assets, uint256 _collateralRate, uint256 _hundredPC) external payable {
consolidatePendingStakes();
if (!isSequencerActive()) revert Errors.L2SequencerUnavailable();
(,int256 priceEurUsd,,,) = Chainlink.AggregatorV3Interface(eurUsd).latestRoundData();
uint256 stakeTotal = getStakeTotal();
uint256 burnEuros;
uint256 nativePurchased;
for (uint256 j = 0; j < holders.length; j++) {
Position memory _position = positions[holders[j]];
uint256 _positionStake = stake(_position);
if (_positionStake > 0) {
for (uint256 i = 0; i < _assets.length; i++) {
ILiquidationPoolManager.Asset memory asset = _assets[i];
if (asset.amount > 0) {
if (!isSequencerActive()) revert Errors.L2SequencerUnavailable();
(,int256 assetPriceUsd,,,) = Chainlink.AggregatorV3Interface(asset.token.clAddr).latestRoundData();
...
function isSequencerActive() internal view returns (bool) {
(, int256 answer, uint256 startedAt,,) = sequencer.latestRoundData();
if (block.timestamp - startedAt <= GRACE_PERIOD_TIME || answer == 1)
return false;
return true;
}
Updates
Lead Judging Commences
hrishibhat over 1 year ago
Submission Judgement Published Reason: Known issue
Assigned finding tags:
Arbitrum-sequncer
Prize pool breakdown
Total prize
20,000 USDC
nSLOC
60933 USDC / LOC
17,500 USDC
2,500 USDC
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