Zaros Part 1
Zaros
DeFiFoundry
60,000 USDC
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Submission Details
Severity: medium
Valid

Sequencer status is not implemented correctly, possibly resulting in stale prices

Cryptor

Summary

No check for startedAt = 0, can result in stale prices reported by the chainlink oracle

Vulnerability Details

The protocol attemps to protect itself from stale price feeds from Chainlink using the following the following code

https://github.com/Cyfrin/2024-07-zaros/blob/35b344033dbf37de76a53783de4d74187f88c3e7/src/external/chainlink/ChainlinkUtil.sol#L41-L57

if (address(sequencerUptimeFeed) != address(0)) {
try sequencerUptimeFeed.latestRoundData() returns (
uint80, int256 answer, uint256 startedAt, uint256, uint80
) {
bool isSequencerUp = answer == 0;
if (!isSequencerUp) {
revert Errors.OracleSequencerUptimeFeedIsDown(address(sequencerUptimeFeed));
}
​
uint256 timeSinceUp = block.timestamp - startedAt;
if (timeSinceUp <= Constants.SEQUENCER_GRACE_PERIOD_TIME) {
revert Errors.GracePeriodNotOver();
}
} catch {
revert Errors.InvalidSequencerUptimeFeedReturn();
}
}

The problem here is that there is no check that startedAt = 0. According to the chainlink docs, if the sequencer is down, both startedAt and answer are equal to 0. However there is only a check that the answer is equal to 0. This means that in the situation that the both startedAt and the answer are equal to 0, the function getPrice should revert, but in this case it will not since block.timestamp - 0 (startedAt), will always be greater that the default grace period time which is 3600. See the except below

![chainlink] (https://cdn.discordapp.com/attachments/1165340854853042200/1267641765029085184/image.png?ex=66a986e4&is=66a83564&hm=48c7b42d0398578bfddc19c9392cc164f2dde0adedefad82b204c3df644faa63&)

Impact

The current implementation of the chainlink sequencer checks will not wokr properly causing the function getprice to pass during sitautions where the sequencer is offline, resulting in unexpected results

Tools Used

Manual Review

Recommendations

Add a check to revert if startedAt = 0.

Updates

Lead Judging Commences

inallhonesty Lead Judge over 1 year ago
Submission Judgement Published
Validated
Assigned finding tags:

Inadequate implementation of sequencer check

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