The Standard

Summary

When utilizing Chainlink in L2 chains like Arbitrum, it's important to ensure that the prices provided are not falsely perceived as fresh, even when the sequencer is down.

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

Vulnerability Details

The project will be deployed on Arbitrum. However, there is no check if the Arbitrum Sequencer is active. The sequencer being down has happened in the past - Arbitrum sequencer suffers 10 hours outage.

The required check to make sure the sequencer is active is not present in the code:

Impact

In the case of an Arbitrum outage, a malicious actor can exploit the protocol.

Tools Used

Manual review

Recommendations

Implement a method to check if the sequencer is down. Follow the Chainlink docs for dealing with EVM chains: https://docs.chain.link/data-feeds/l2-sequencer-feeds#example-code