Hawk High

Summary

The function graduateAndUpgrade miscalculates how much each teacher should receive from the bursary. Instead of distributing 35% of the bursary across all teachers, it incorrectly gives each teacher the full 35% share. This results in massive overpayment and could cause the contract to transfer more than it holds.

Impact

• Overdraw the contract’s USDC balance

• Fail with a transfer revert due to insufficient funds

• Lead to financial loss if exploited before failure

Proof Of Concept

Let’s say:

• Bursary = 1000e18

• TEACHER_WAGE = 35 (representing 35%)

• Number of teacher = 5

According to current code

So each teacher will get 350e18, which will total to

This exceeds the 1000e18 bursary by 750e18

Tools Used

• Manual code review

Solution

Distribute the 35% share evenly across all teachers:

With this correction:

• teacherShare = 350e18

• payPerTeacher = 70e18

• total payout = 5 × 70e18 = 350e18

Recommendations

Replace this:

With this: