Submission Details
Severity:
refund function vulnerable to reentrancy attack
Summary
The refund function is vulnerable to a reentrancy attack.
Vulnerability Details
The refund function is vulnerable to a reentrancy attack because it doesn't update all the logic before sending the users funds back to them.
Impact
allows the attacker to drain the entire contracts funds.
Tools Used
Manual Review, Slither
Recommendations
use CEI (Checks, Effects, Interactions). only send ether once you have finished updating all the logic.
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);
- players[playerIndex] = address(0);
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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