Submission Details
Severity:
Reentrancy in refund()
Summary
refund() does not follow CEI pattern therefore it is vulnerable to reentrancy attack.
Vulnerability Details
players[playerIndex] = address(0); is updated after payable(msg.sender).sendValue(entranceFee);, so attacker can do reentrancy attack during the callback to drain the contract.
Impact
The contract's balance will be drained.
Tools Used
Manual review
Recommendations
Rewrite the function:
function refund(uint256 playerIndex) public {
address playerAddress = players[playerIndex];
require(playerAddress == msg.sender, "PuppyRaffle: Only the player can refund");
require(playerAddress != address(0), "PuppyRaffle: Player already refunded, or is not active");
players[playerIndex] = address(0);
payable(msg.sender).sendValue(entranceFee);
emit RaffleRefunded(playerAddress);
}
Updates
Lead Judging Commences
Hamiltonite about 2 years ago
Submission Judgement Published Assigned finding tags:
reentrancy-in-refund
reentrancy in refund() function
Rewards breakdown
nSLOC
143This contest has a flat reward structure with the following payouts:
100 EXP
20 EXP
2 EXP
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