Root + Impact

Root: The MESSAGE_TYPEHASH constant contains a typo in the type signature string: "SnowmanClaim(addres receiver, uint256 amount)" with "addres" instead of "address".

Impact: The incorrect type hash will cause all EIP-712 signature validations to fail, making the entire airdrop mechanism non-functional as no valid signatures can be generated or verified.

Description

• Normal Behavior: EIP-712 type hash strings must exactly match the struct definition for signature validation to work correctly.

• Specific Issue: The typo "addres" instead of "address" creates a hash that doesn't match what wallets and signing libraries generate when creating signatures for the correct SnowmanClaim struct, causing all signature verifications to fail.

Risk

Likelihood: High

• Every signature validation will fail due to the incorrect type hash

• The error affects 100% of claim attempts, making it immediately noticeable

• Users cannot successfully claim any NFTs through the intended mechanism

Impact: High

• Complete Airdrop Failure: No users can claim NFTs as all signatures will be invalid

• Broken EIP-712 Implementation: Signature validation mechanism is completely non-functional

• Contract Redeployment Required: The immutable constant cannot be fixed without redeploying the entire contract

Proof of Concept

The below code shows proof of the typo

Recommended Mitigation

Fix the typo in the EIP-712 type hash declaration to enable proper signature validation.