Liquid Staking

Summary

The updateStrategyRewards function in the provided Solidity code incorrectly checks if a strategy exists for msg.sender instead of verifying the existence of the strategy by its ID.

Vulnerability Details

https://github.com/Cyfrin/2024-09-stakelink/blob/main/contracts/core/StakingPool.sol#L413-L417

• Function: updateStrategyRewards

• Issue: The function checks if msg.sender is authorized by verifying if a strategy exists for msg.sender. This is incorrect as it should check the strategy ID instead.
  
  function below fails as check in if statement assesses the msg.sender instead of each strategy in _strategyIdxs

  function updateStrategyRewards(uint256[] memory _strategyIdxs, bytes memory _data) external {

  if (msg.sender != rebaseController && !_strategyExists(msg.sender))

  revert SenderNotAuthorized();

  _updateStrategyRewards(_strategyIdxs, _data);

  }

Impact

medium

Tools Used

manual review

Recommendations

Modify the function to check the existence of the strategy by its ID rather than msg.sender.

```solidity

function updateStrategyRewards(uint256[] memory _strategyIdxs, bytes memory _data) external {
++for (uint256 i = 0; i < _strategyIdxs.length; i++) {
++uint256 strategyId = _strategyIdxs[i];
++if (msg.sender != rebaseController && !_strategyExists(strategyId))
revert SenderNotAuthorized();
}
_updateStrategyRewards(_strategyIdxs, _data);
}

```