Submission Details
Severity:
enterRaffle function vulnerable to DoS
Summary
The function enterRaffle checks for duplicates by looping through the players storage variable. This will require more gas as the array grows and potentially exceeding block gas limit.
Vulnerability Details
enterRaffle function vulnerable to DoS attack by increasing the players storage variable size
Impact
No new players can enter the raffle until a winner is selected and the players storage variable cleared.
Tools Used
Foundry
Slither
Recommendations
Add a mapping storage variable that maps a player's address to it's active status.
uint256 public immutable entranceFee;
address[] public players;
+ // mapping to check if player is part of the current raffle
+ mapping(address => bool) playerToIsActive;
function enterRaffle(address[] memory newPlayers) public payable {
require(msg.value == entranceFee * newPlayers.length, "PuppyRaffle: Must send enough to enter raffle");
for (uint256 i = 0; i < newPlayers.length; i++) {
+ address newPlayer = newPlayers[i];
+ // Check for duplicates
+ require(!playerToIsActive[newPlayer], "PuppyRaffle: Duplicate player");
players.push(newPlayer);
+ playerToIsActive[newPlayer] = true;
}
- // Check for duplicates
- for (uint256 i = 0; i < players.length - 1; i++) {
- for (uint256 j = i + 1; j < players.length; j++) {
- require(players[i] != players[j], "PuppyRaffle: Duplicate player");
- }
- }
emit RaffleEnter(newPlayers);
}
Note: Additional logic is required to reset player active status when a winner is selected.
Updates
Lead Judging Commences
Hamiltonite about 2 years ago
Submission Judgement Published Assigned finding tags:
denial-of-service-in-enter-raffle
Rewards breakdown
nSLOC
143This contest has a flat reward structure with the following payouts:
100 EXP
20 EXP
2 EXP
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