Hawk High

Summary

The reviewCount mapping in the LevelOne contract is never initialized but is used in the giveReview function, which leads to unexpected behavior.

Vulnerability Details

The reviewCount mapping is declared as a state variable but is never initialized with a default value before being used in a comparison in the giveReview function, like this:

In the giveReview function, there's a check that relies on this uninitialized value:

However, the function never updates reviewCount after the check.

Impact

This vulnerability leads to 2 issues:

First the reviewCount check is effectively useless since it's never incremented and the second problem is that the function will always pass this condition as the default value for uint256 is 0

This undermines the intended restriction mechanism and allow an unlimited number of reviews for a student, manipulating their scores unfairly.

Recommendations

Personally I would initialize the reviewCount mapping for each student when they are enrolled