Mystery Box

Summary

In the transferReward function, the reward is deleted from rewardsOwned[msg.sender] using delete rewardsOwned[msg.sender][_index]. This does not shift the array, so the array will have gaps. This could lead to unintended behavior when interacting with the rewards array.

Vulnerability Details

MysteryBox.sol/Line 76

Impact

Users might lose rewards or experience inconsistent behavior when trying to transfer or claim rewards due to empty array slots caused by the delete operation.

Tools Used

Foundry

Recommendations

Consider using array shifting or swapping the last element with the deleted one before removing it to ensure proper handling of the array.