XDZIBEC - XO-`getBucketStateStakeInfo` function get Incorrect `bucketId_` check

[sherlock-admin]

XDZIBEC

medium

XO-getBucketStateStakeInfo function get Incorrect bucketId_ check

Summary

• The getBucketStateStakeInfo function has a vulnerability that does not check if the bucket ID exists before returning any information so this can be exploit and can the attacker call the function with a bucket ID that does not exist, and the function would return incorrect information about the LP amount.

  Vulnerability Detail

  
  function getBucketStateStakeInfo(
      uint256 tokenId_,
      uint256 bucketId_
  ) external view returns (uint256, uint256);

}

-The vulnerability is in the `getBucketStateStakeInfo` function it's returns the `LP` amount and the exchange rate for a given bucket and a given stake, at stake time, the function does not check if the bucket exists.  means that if an attacker calls the function with a bucket ID that does not exist, the function will return incorrect information.
## Impact
- the vulnerability can cause a material loss of funds.
## Code Snippet
- https://github.com/sherlock-audit/2023-04-ajna/blob/main/ajna-core/src/interfaces/rewards/IRewardsManagerState.sol#L70C4-L75C2
## Tool used

Manual Review

## Recommendation
This can be fixing this problem :
```solidity
if (bucketId_ >= stakeInfo.snapshot.length) {
    // Bucket does not exist
    return (0, 0);
}