Liquid Staking

Summary

StakingRewardsPool does not use IStakingRewardsPool to set minimum requirements for the contract.

Vulnerability Details

Since StakingRewardsPool does not inherit the list of function definitions from IStakingRewardsPool, there are two separate interfaces for the StakingRewardsPool contract. One is "StakingRewardsPool.sol" itself and the other is "IStakingRewardsPool.sol". This may cause the following problems:

• when changing one of the interfaces, remember to change the other one

• any error or discrepancy between interfaces may disrupt interaction with the deployed StakingRewardsPool contract

Impact

The PriorityPool contract uses IStakingRewardsPool to interact with StakingRewardsPool. Any difference between these two interfaces can cause communication problems between contracts. It is known that there are the following discrepancies:

• StakingRewardsPool: function sharesOf(address _account) public view returns (uint256) vs IStakingRewardsPool: function sharesOf(address _account) external view returns (uint256)

• StakingRewardsPool: function getSharesByStake(uint256 _amount) public view returns (uint256) vs IStakingRewardsPool: function getSharesByStake(uint256 _amount) external view returns (uint256)

• StakingRewardsPool: function getStakeByShares(uint256 _amount) public view returns (uint256) vs IStakingRewardsPool: function getStakeByShares(uint256 _amount) external view returns (uint256)

• StakingRewardsPool: uint256 public totalShares vs IStakingRewardsPool: function totalShares() external view returns (uint256)

• StakingRewardsPool: function totalSupply() public view returns (uint256) vs IStakingRewardsPool: function totalSupply() external view returns (uint256)

These are minor differences public vs external visibility, but it can change in the future if not properly managed.

Tools Used

Manual review.

Recommendations

Leaving it this way will only make the problem worse in the future. Make sure StakingRewardsPool is IStakingRewardsPool and correct any discrepancies according to the list above.