Root + Impact

Description

• In the claim() function, the duplicate claim check uses _treasureHash (an immutable private variable that is NEVER initialized in the constructor, making it permanently bytes32(0)) instead of the caller-supplied treasureHash parameter. The check if (claimed[_treasureHash]) revert AlreadyClaimed(treasureHash); will always readclaimed[bytes32(0)], which is false. Meanwhile, _markClaimed(treasureHash) correctly marks the caller-supplied hash, but the guard never checks it. This means any valid ZK proof for a given treasure can be replayed up to MAX_TREASURES (10) times, limited only by the claimsCount cap, allowing a single treasure finder to drain the entire 100 ETH contract balance.

Risk

Impact:

• A single treasure finder can replay their valid ZK proof up to 10 times (limited by MAX_TREASURES), draining the entire 100 ETH contract balance. Each replay uses a different recipient address (since recipient != msg.sender is enforced), but the attacker controls all recipient addresses. This completely breaks the core game mechanic and results in total loss of funds.

  
  

POC

no need

Recommended Mitigation