Olympus DAO contest - Dravee's results

Lines of code

https://github.com/code-423n4/2022-08-olympus/blob/b5e139d732eb4c07102f149fb9426d356af617aa/src/modules/PRICE.sol#L161 https://github.com/code-423n4/2022-08-olympus/blob/b5e139d732eb4c07102f149fb9426d356af617aa/src/modules/PRICE.sol#L170

Vulnerability details

Impact

latestRoundData() is used to fetch the asset price from a Chainlink aggregator, but it's missing additional validations to ensure that the round is complete. If there is a problem with Chainlink starting a new round and finding consensus on the new value for the oracle (e.g. Chainlink nodes abandon the oracle, chain congestion, vulnerability/attacks on the Chainlink system) consumers of this contract may continue using outdated stale data / stale prices.

Proof of Concept

modules/PRICE.sol:161:            (, int256 ohmEthPriceInt, , uint256 updatedAt, ) = _ohmEthPriceFeed.latestRoundData();
modules/PRICE.sol:170:            (, reserveEthPriceInt, , updatedAt, ) = _reserveEthPriceFeed.latestRoundData();

Recommended Mitigation Steps

Consider adding missing checks for stale data.