TwentyOne
First Flight #29
Beginner FriendlyGameFiFoundrySolidity
100 EXP
View results
Previous Next
Submission Details
Severity: high
Valid

[M-01] Lack of Essential Administrative Controls in TwentyOne Contract

iepathos

Summary

The TwentyOne contract lacks critical administrative controls necessary for managing a gambling contract that handles user funds. Without these controls, the contract has no mechanism to handle emergencies, manage house funds, or protect against potential vulnerabilities.

Vulnerability Details

Location: src/TwentyOne.sol

The contract currently lacks several essential administrative features:

  1. No owner/admin role implementation

  2. No emergency pause mechanism

  3. No way to withdraw accumulated house funds

  4. No way to add house funds if depleted

  5. No mechanism to handle stuck funds

Impact

The lack of administrative controls presents several risks:

  1. Financial Risks

    • Stuck funds cannot be recovered

    • House could run out of funds to pay winners

    • No way to top up house funds if depleted

  2. Security Risks

    • No way to pause the contract if a vulnerability is discovered

    • No way to upgrade or fix critical bugs

    • No protection against potential exploits

  3. Operational Risks

    • No mechanism to handle edge cases

    • No way to manage house operations

    • Limited ability to respond to emergencies

Tools Used

  • Manual Code Review

  • Foundry Testing Framework

  • Static Analysis

Recommendations

  1. Implement Ownable Pattern:

import "@openzeppelin/contracts/access/Ownable.sol";
​
contract TwentyOne is Ownable {
bool public paused;
modifier whenNotPaused() {
require(!paused, "Contract is paused");
_;
}
function togglePause() external onlyOwner {
paused = !paused;
}
}

  1. Add House Fund Management:

function withdrawHouseFunds(uint256 amount) external onlyOwner {
require(amount <= address(this).balance, "Insufficient funds");
payable(owner()).transfer(amount);
}
​
function addHouseFunds() external payable onlyOwner {
// Allows adding funds to the house
}

  1. Emergency Functions:

function emergencyWithdraw() external onlyOwner {
uint256 balance = address(this).balance;
payable(owner()).transfer(balance);
}
​
function refundActiveGame(address player) external onlyOwner {
require(playersDeck[player].playersCards.length > 0, "No active game");
payable(player).transfer(1 ether);
delete playersDeck[player].playersCards;
delete dealersDeck[player].dealersCards;
delete availableCards[player];
}

  1. Additional Recommendations:

    • Implement a minimum house balance requirement

    • Add events for administrative

Updates

Lead Judging Commences

inallhonesty Lead Judge
11 months ago
inallhonesty Lead Judge 11 months ago
Submission Judgement Published
Validated
Assigned finding tags:

Owner has no method to withdraw

Contract Lacks Mechanism to Initialize or Deposit Ether

Support

FAQs

Can't find an answer? Chat with us on Discord, Twitter or Linkedin.