Last Man Standing
First Flight #45
Beginner FriendlyFoundrySolidity
100 EXP
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Submission Details
Severity: medium
Valid

The `claimThrone` function doesn't implement logic to share portion of claim fee with a previous king

0xbyteknight

Root + Impact

Description

  • The application design assumes that during the claimThrone function execution, a previous king will receive a small portion of a new claim fee. The functional implements defensive check to make sure that platformFee doesn't exceed available amount after previousKingPayout.

  • However, the claimThrone function misses essential logic to calculate and send a portion of fee that should be send to a previous king. Additionaly, it makes the mentioned defensive check useless and causes higher gas fee during deployment.

uint256 sentAmount = msg.value;
@> uint256 previousKingPayout = 0;
uint256 currentPlatformFee = 0;
uint256 amountToPot = 0;
​
// Calculate platform fee
currentPlatformFee = (sentAmount * platformFeePercentage) / 100;
​
// Defensive check to ensure platformFee doesn't exceed available amount after previousKingPayout
@> if (currentPlatformFee > (sentAmount - previousKingPayout)) {
@> currentPlatformFee = sentAmount - previousKingPayout;
}

Risk

Likelihood:

  • The issue will occur every time from the second call to the claim Throne function.

Impact:

  • Previous king won't receive any portion of a new claim fee.

  • Additional defence check and unused code costs approximately additional 9711 gas during deployment.

Proof of Concept

​

Recommended Mitigation

Depending on how an owner of the game wants to proceed, there 2 ways to solve this issue:

  1. Implement the missing logic for calculation and sending a portion of fee to a previous king.

  2. Remove unnecesary checks and code from the claimThrone function as below.

uint256 sentAmount = msg.value;
- uint256 previousKingPayout = 0;
uint256 currentPlatformFee = 0;
uint256 amountToPot = 0;
​
// Calculate platform fee
currentPlatformFee = (sentAmount * platformFeePercentage) / 100;
​
- // Defensive check to ensure platformFee doesn't exceed available amount after previousKingPayout
- if (currentPlatformFee > (sentAmount - previousKingPayout)) {
- currentPlatformFee = sentAmount - previousKingPayout;
- }
platformFeesBalance = platformFeesBalance + currentPlatformFee;
Updates

Appeal created

inallhonesty Lead Judge about 2 months ago
Submission Judgement Published
Validated
Assigned finding tags:

Missing Previous King Payout Functionality

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