Submission Details
Impact:
Likelihood:
Not following CEI in `LevelOne::enroll` pattern allows for reentrancy
Summary
The LevelOne contract does not follow the Checks-Effects-Interactions (CEI) pattern, which can lead to reentrancy vulnerabilities. The issue is not direct threat, but it is a good practice to follow the CEI pattern to prevent potential reentrancy attacks.
function enroll() external notYetInSession {
if (isTeacher[msg.sender] || msg.sender == principal) {
revert HH__NotAllowed();
}
if (isStudent[msg.sender]) {
revert HH__StudentExists();
}
@> usdc.safeTransferFrom(msg.sender, address(this), schoolFees);
listOfStudents.push(msg.sender);
isStudent[msg.sender] = true;
studentScore[msg.sender] = 100;
bursary += schoolFees;
emit Enrolled(msg.sender);
}
Impact
A malicious contract could re-enter the LevelOne contract during a function call.
Tools Used
Manual review.
Recommendations
Refactor the LevelOne::enroll function to follow the CEI pattern. Ensure that all state updates are performed before any external calls.
Rewards breakdown
nSLOC
243This contest has a flat reward structure with the following payouts:
100 EXP
20 EXP
2 EXP
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