Sparkn

Summary

While calling the setContest the owner can loose track of the contest Id, because we are not maintaining any counter variable for that and owner can also pass a redundant contest id. Also there is no mapping which will show which contest id belongs to which organizer.
There is a need to ensure that for every new contest made there is a unique contest id for that.

Vulnerability Details

In case the admin loose track of the contest id then it will become difficult to find it. Also, it is suggested that the contest id should always go serially.

Impact

It can impact how the admin will interact with the contract, and can make it difficult for them to maintain all the contest ids.

Tools Used

Manual Detection

Recommendations

Using a counter variable will help to maintain the unique contest id and also for people to get details about which contest belong to which organizer we must maintain a mapping for that.
To use a counter variable for the contest ids and also use a mapping which keeps track of the contest id.