The Standard

Summary

Chainlink recommends that users using price oracles, check whether the Arbitrum Sequencer is active.

Vulnerability Details

If the sequencer goes down, the index oracles may have stale prices, since L2-submitted transactions (i.e. by the aggregating oracles) will not be processed.

Impact

If stale prices are used, this can results in false liquidation or over-borrowing.

Tools Used

Manual review.

Recommendations

Use a chainlink oracle to determine whether the sequencer is offline or not. You can follow this and the example code provided by Chainlink.