SNARKeling Treasure Hunt
First Flight #59
Beginner FriendlyGameFiFoundry
100 EXP
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Submission Details
Impact: low
Likelihood: high

Incorrect Event Emission

Author Revealed upon completion

Root + Impact

Description

Events are the primary way off-chain systems keep track of contract state changes. The Claimed event is intended to signal who successfully found a treasure and received the reward.

In the current implementation, the code transfers REWARD to the recipient, but logs the msg.sender. If a user uses a "relayer" or a secondary wallet to pay for gas while sending the funds to their hardware wallet (recipient), the public record will incorrectly show the gas-paying wallet as the winner.

// Root cause in the codebase
function claim(bytes calldata proof, bytes32 treasureHash, address payable recipient) external nonReentrant() {
// ... logic ...
(bool sent, ) = recipient.call{value: REWARD}("");
require(sent, "ETH_TRANSFER_FAILED");
​
@> emit Claimed(treasureHash, msg.sender); // Should be recipient
}

Risk

Likelihood: High

  • The code is hardcoded to log the wrong address.

Impact: Low

  • It does not result in a loss of funds (the money still goes to the right place), but it corrupts the "source of truth" for the hunt's history and creates confusion for users.

Proof of Concept

​

Recommended Mitigation

Update the event to emit the address that actually received the reward.

- emit Claimed(treasureHash, msg.sender);
+ emit Claimed(treasureHash, recipient);

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