Mystery Box

Summary

The random value generation in the openBox function is easily predicatble making it an easy target for malicious users

Vulnerability Details

In the function openBox there is the randomvalue that is being generated by the following line of code:

A malicious user could easily predict with his address at what timestamp they should call the function to get thge maximum rewards

Impact

Since the logic of the contract depends on that randomness i would say that the impact on the trust and the logic of the contract is huge.

Tools Used

Manual

Recommendations

There are a few good way to create random values but i would recommend finding another way to chose between rewards and not through randomness.