Submission Details
Severity:
TwentyOne::endGame() function does not have a check for available funds.
Summary
TwentyOne::endGame() function does not have a check for available funds.
Vulnerability Details
The endGame() function doesnot have a check for available funds.
function endGame(address player, bool playerWon) public {
//-->> no check for if funds are avaialbe or not
delete playersDeck[player].playersCards;
delete dealersDeck[player].dealersCards;
delete availableCards[player];
if (playerWon) {
payable(player).transfer(2 ether);
emit FeeWithdrawn(player, 2 ether);
}
}
Impact
The function will break and revert as the funds are not available.
Proof of Code
Here are two tests
Without funding the contract(Does not PASS)
With funding the contract(PASSES)
function testendgamerevertsIfNotFunded() public {
vm.startPrank(player1); // Start acting as player1
// Start the game with 1 ether bet
twentyOne.startGame{value: 1 ether}();
bool playerWon = true;
vm.expectRevert();
twentyOne.endGame(player1, playerWon);
vm.stopPrank();
}
function testendgame() public {
// Example player1 address
// Fund player1 with enough Ether
vm.deal(player1, 10 ether);
// Fund the contract with enough Ether for payouts
vm.deal(address(twentyOne), 10 ether);
// Start acting as player1
vm.startPrank(player1);
uint256 initialBalance = player1.balance;
// Start the game with 1 ether bet
twentyOne.startGame{value: 1 ether}();
// Simulate a winning scenario
bool playerWon = true;
// Call endGame to conclude the game
twentyOne.endGame(player1, playerWon);
// Assert that player1's balance increased (2 ether win minus 1 ether bet)
assert(player1.balance == initialBalance + 1 ether);
// Stop acting as player1
vm.stopPrank();
}
Tools Used
Manual Review
Recommendations
Add a check for the contract's balance to be greater or equal to the total pool of the game.
function endGame(address player, bool playerWon) public {
+ require(address(this).balance >= 2 ether, "Insufficient contract balance");
delete playersDeck[player].playersCards;
delete dealersDeck[player].dealersCards;
delete availableCards[player];
if (playerWon) {
payable(player).transfer(2 ether);
emit FeeWithdrawn(player, 2 ether);
}
}
Updates
Lead Judging Commences
inallhonesty 11 months ago
Submission Judgement Published Assigned finding tags:
Insufficient balance for payouts / Lack of Contract Balance Check Before Starting Game
Rewards breakdown
nSLOC
147This contest has a flat reward structure with the following payouts:
100 EXP
20 EXP
2 EXP
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