Summary

If the Arbitrum Sequencer goes down, oracle data will not be kept up to date, and thus could become stale. However, users are able to continue to interact with the protocol directly through the L1 optimistic rollup contract. You can review Chainlink docs on L2 Sequencer Uptime Feeds for more details on this.

Vulnerability Details

As a result, users may be able to use the protocol while oracle feeds are stale.

Impact

A user has an account with 100 tokens, valued at 2 USD each, and no borrows
The Arbitrum sequencer goes down temporarily
While it's down, the price of the token falls to 1 USD each
The current value of the user's account is 100 ETH, so they should be able to borrow a maximum of 50 USD to keep account healthy.
Because of the stale price, the protocol lets them borrow 100 USD.A user has an account with 100 tokens, valued at 2 USD each, and no borrows
The Arbitrum sequencer goes down temporarily
While it's down, the price of the token falls to 1 USD each
The current value of the user's account is 100 ETH, so they should be able to borrow a maximum of 50 USD to keep account healthy.
Because of the stale price, the protocol lets them borrow 100 USD.

Tools Used

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