Hawk High

Summary

The giveReview function fails to increment the reviewCount for students, allowing teachers to submit unlimited reviews despite the contract's requirement of a maximum of four reviews per student. Additionally, the system upgrade process does not enforce that all students have received exactly four reviews, violating core protocol rules.

Vulnerability Details

Affected Components:

giveReview Function: The function does not increment the reviewCount after submitting a review.

graduateAndUpgrade Function: Missing validation to ensure all students have exactly four reviews before upgrading.

Unlimited Reviews:

In giveReview, reviewCount[_student] is checked (require(reviewCount[_student] < 5) but never incremented. This allows bypassing the intended four-review limit.

Missing Review Validation During Upgrade:

The graduateAndUpgrade function does not verify if all students have received four reviews.

Impact

• Unlimited Reviews: Students may receive more than four reviews, skewing scores and allowing unfair graduations.

• Incomplete Reviews: Upgrades can proceed without all students completing four reviews, violating protocol rules and risking invalid state transitions.

Tools Used

Recommendations

Increment reviewCount in giveReview:

Enforce Four-Review Requirement During Upgrade:

Adjust Review Count Check (Optional):

Clarify the maximum reviews by updating the check to reviewCount[_student] < 4 if the intended limit is four (current logic allows five due to <5).