Oracle begins in stale state due to uninitialized lastOracleUpdateTime

[CergyK]

Description

In the context of BinaryEligibilityOracleEarningPowerCalculator, lastOracleUpdateTime is used to determine if the oracle setting the scores for individual delegatees is stale. Unfortunately this value is not set in the constructor, meaning the oracle begins in the stale state. This means that a user can initialize many deposits which have max earning power right after calculator creation. Unless these deposits are bumped using requestedTip == 0, these deposits will be valid when rewards are first notified and will be eligible for rewards.

BinaryEligibilityOracleEarningPowerCalculator.sol#L109-L122:

constructor(
    address _owner,
    address _scoreOracle,
    uint256 _staleOracleWindow,
    address _oraclePauseGuardian,
    uint256 _delegateeScoreEligibilityThreshold,
    uint256 _updateEligibilityDelay
  ) Ownable(_owner) {
    _setScoreOracle(_scoreOracle);
    STALE_ORACLE_WINDOW = _staleOracleWindow;
    _setOraclePauseGuardian(_oraclePauseGuardian);
    _setDelegateeScoreEligibilityThreshold(_delegateeScoreEligibilityThreshold);
    _setUpdateEligibilityDelay(_updateEligibilityDelay);
    //@audit missing lastOracleUpdateTime initialization 
  }

Recommendation

Please consider initializing lastOracleUpdateTime, to avoid it being stale at the start:

BinaryEligibilityOracleEarningPowerCalculator.sol#L109-L122:

constructor(
    address _owner,
    address _scoreOracle,
    uint256 _staleOracleWindow,
    address _oraclePauseGuardian,
    uint256 _delegateeScoreEligibilityThreshold,
    uint256 _updateEligibilityDelay
  ) Ownable(_owner) {
    _setScoreOracle(_scoreOracle);
    STALE_ORACLE_WINDOW = _staleOracleWindow;
    _setOraclePauseGuardian(_oraclePauseGuardian);
    _setDelegateeScoreEligibilityThreshold(_delegateeScoreEligibilityThreshold);
    _setUpdateEligibilityDelay(_updateEligibilityDelay);
+   lastOracleUpdateTime = block.timestamp;
  }

[alexkeating]

Will fix

[CergyK]

Fixed by withtally/staker#89