Submission Details
Impact:
Likelihood:
CEI Pattern not followed in `LevelOne::enroll`
Summary
CEI Pattern not followed in LevelOne::enroll function
Vulnerability Details
In LevelOne::enroll function external function call are made before the contract state changes effects which is against the CEI Pattern(Checks, Effects, Interactions).
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
Some form of reentrancy bugs can arise if CEI pattern is not followed properly.
Recommendations
We should do the contracts state changes before the external contract function calls.
- 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);
+ usdc.safeTransferFrom(msg.sender, address(this), schoolFees);
Rewards breakdown
nSLOC
243This contest has a flat reward structure with the following payouts:
100 EXP
20 EXP
2 EXP
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