Hawk High
First Flight #39
Beginner FriendlySolidity
100 EXP
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Submission Details
Impact: medium
Likelihood: medium
Invalid

Students are limited to 5 reviews and not 4.

5am

Summary

"Students must have gotten all reviews before system upgrade. System upgrade should not occur if any student has not gotten 4 reviews (one for each week)" - This implies that the max amount of reviews a student should have is 4 (one for each week). However, the giveReview function actually checks if the students current review count is less than 5, allowing students to be given another review after already receiving all 4 reviews.

Vulnerability Details

The highlighted line checks that reviewCount[_student] < 5 rather than reviewCount[_student] < 4.

function giveReview(address _student, bool review) public onlyTeacher {
if (!isStudent[_student]) {
revert HH__StudentDoesNotExist();
}
@> require(reviewCount[_student] < 5, "Student review count exceeded!!!");
require(block.timestamp >= lastReviewTime[_student] + reviewTime, "Reviews can only be given once per week");
​
// where `false` is a bad review and true is a good review
if (!review) {
studentScore[_student] -= 10;
}
​
// Update last review time
lastReviewTime[_student] = block.timestamp;
​
emit ReviewGiven(_student, review, studentScore[_student]);
}

Impact

This means that if a students score could be unfairly decreased if a teacher calls giveReview with a negative review after that student has already received all 4 reviews.

Tools Used

Manual review

Recommendations

Require reviewCount[student] to be less than 4.

function giveReview(address _student, bool review) public onlyTeacher {
if (!isStudent[_student]) {
revert HH__StudentDoesNotExist();
}
- require(reviewCount[_student] < 5, "Student review count exceeded!!!");
+ require(reviewCount[_student] < 4, "Student review count exceeded!!!");
require(block.timestamp >= lastReviewTime[_student] + reviewTime, "Reviews can only be given once per week");
​
// where `false` is a bad review and true is a good review
if (!review) {
studentScore[_student] -= 10;
}
​
// Update last review time
lastReviewTime[_student] = block.timestamp;
​
emit ReviewGiven(_student, review, studentScore[_student]);
}
Updates

Lead Judging Commences

yeahchibyke Lead Judge about 1 month ago
Submission Judgement Published
Invalidated
Reason: Incorrect statement

Appeal created

5am Submitter
about 1 month ago
yeahchibyke Lead Judge
about 1 month ago
yeahchibyke Lead Judge about 1 month ago
Submission Judgement Published
Invalidated
Reason: Incorrect statement

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