Little Clay Parakeet - PythOracle Staleness check is inverted

[sherlock-admin3]

Little Clay Parakeet

Medium

PythOracle Staleness check is inverted

Summary

The Stale Price check in the PythOracle contract is inverted. This would lead to two things:

1. Transaction reverts if the latest price publishTime is >= block.timestamp - noOlderThan, which could happen very often if its a frequently updated price feed. Every contract that uses this price wouldn't be able to work.
2. The prices would have been older than PythOracle.noOlderThan

Root Cause

The Stale price check is inverted.

Internal pre-conditions

No response

External pre-conditions

Price feed not updated in the last PythOracle.noOlderThan seconds.

Attack Path

1. User waits for the oracle to not be updated and also checks that his tokenIn has dropped in value.
2. He manages to get the previous stale price for higher USDC value on his tokenIn than the actual current value.

Impact

No response

PoC

No response

Mitigation

Revert the Stale Price check