helpMePlease - Chainlink's latestRoundData return stale or incorrect result

[sherlock-admin]

helpMePlease

medium

Chainlink's latestRoundData return stale or incorrect result

Summary

Vulnerability Detail

https://github.com/sherlock-audit/2023-04-blueberry/blob/96eb1829571dc46e1a387985bd56989702c5e1dc/blueberry-core/contracts/oracle/ChainlinkAdapterOracle.sol#L87

There isn't any kind of condition to check if the return value indicates stale data.

Impact

On ChainlinkAdapterOracle.sol, you are using latestRoundData, but there is no check if the return value indicates stale data.

 function getPrice(address token_) external view override returns (uint256) {
        // remap token if possible
        address token = remappedTokens[token_];
        if (token == address(0)) token = token_;

        uint256 maxDelayTime = timeGaps[token];
        if (maxDelayTime == 0) revert Errors.NO_MAX_DELAY(token_);

        // Get token-USD price
        uint256 decimals = registry.decimals(token, USD);
        (, int256 answer, , uint256 updatedAt, ) = registry.latestRoundData( 
        
            token,
            USD
        );
        if (updatedAt < block.timestamp - maxDelayTime)
            revert Errors.PRICE_OUTDATED(token_);
        if (answer <= 0) revert Errors.PRICE_NEGATIVE(token_);

        return
            (answer.toUint256() * Constants.PRICE_PRECISION) / 10 ** decimals;
    }

This could lead to stale prices according to the Chainlink documentation:
https://docs.chain.link/data-feeds/price-feeds/historical-data
Related report:
sherlock-audit/2023-02-blueberry-judging#94

Code Snippet

https://github.com/sherlock-audit/2023-04-blueberry/blob/96eb1829571dc46e1a387985bd56989702c5e1dc/blueberry-core/contracts/oracle/ChainlinkAdapterOracle.sol#L87

Tool used

Manual Review

Recommendation

function getPrice(address _token) external view override returns (uint256) {
        // remap token if possible
        address token = remappedTokens[_token];
        if (token == address(0)) token = _token;

        uint256 maxDelayTime = maxDelayTimes[token];
        if (maxDelayTime == 0) revert NO_MAX_DELAY(_token);

        // try to get token-USD price
        uint256 decimals = registry.decimals(token, USD);
        (uint80 roundID, int256 answer, uint256 timestamp, uint256 updatedAt, ) = registry.latestRoundData(
            token,
            USD
        );
        //Solution
        require(updatedAt >= roundID, "Stale price");
        require(timestamp != 0,"Round not complete");
        require(answer > 0,"Chainlink answer reporting 0");

        if (updatedAt < block.timestamp - maxDelayTime)
            revert PRICE_OUTDATED(_token);

        return (answer.toUint256() * 1e18) / 10**decimals;
    }

Duplicate of #118