Prepared by:
HALBORN
Last Updated 10/23/2025
Date of Engagement: October 6th, 2025 - October 10th, 2025
Summary
100% of all REPORTED Findings have been addressed
All findings
14
Critical
0
High
1
Medium
0
Low
1
Informational
12
Table of Contents
1. Introduction
Snag engaged Halborn to conduct a comprehensive security assessment of the Snag Airdrop V2 smart contracts beginning on October 6th, 2025, and concluding on October 10th, 2025. The scope of this assessment was limited to the smart contracts provided to the Halborn team. Commit hashes, scope boundaries, and additional details are documented in the Scope section of this report.
The Snag Airdrop V2 Protocol serves as an on-chain airdrop distribution and staking framework designed to provide secure, flexible, and auditable token distribution mechanisms for partner projects. It enables protocols to launch claim contracts through a signed factory that leverages EIP-712–based authorization, ensuring only authenticated deployments.
2. Assessment Summary
Halborn assigned a full-time security engineer to review the security of the smart contracts in scope. The engineer is a blockchain and smart contract security expert with advanced penetration testing and smart contract auditing skills, and deep knowledge of multiple blockchain protocols.
The purpose of the assessment is to:
Identify potential security issues within the smart contracts.
Ensure that smart contract functionality operates as intended.
In summary, Halborn identified several areas for improvement to reduce both the likelihood and impact of potential risks, which were successfully addressed by the Snag team. The main issues addressed include:
Solved the unclaimed allocation issue by enforcing a 100% claim distribution validation to prevent permanently locked user funds.Solved unnecessary computation by moving the len declaration inside the else block so it’s only executed when required.Solved potential DoS risks in claimUnlocked() and stakeFor() by adding caller restrictions and upper bounds to limit excessive stake creation.
3. SCOPE
- contracts/Claim.sol
- contracts/Factory.sol
- contracts/LinearStake.sol
4. Findings Overview
| Security analysis | Risk level | Remediation |
|---|---|---|
| Partial claims permanently lock remaining allocation | High | Solved - 10/07/2025 |
| Inefficient variable scope for len in claimUnlocked() function | Low | Solved - 10/10/2025 |
| Unbounded loop in claimUnlocked() enables DoS via unrestricted caller check in stakeFor() calls | Informational | Solved - 10/10/2025 |
| TransferFailed error is declared but never used | Informational | Solved - 10/10/2025 |
| AlreadyClaimed reused as initialization guard | Informational | Solved - 10/10/2025 |
| Declared all error imports clean | Informational | Solved - 10/10/2025 |
| __snagFee_init function can be refactored for better structure and readability | Informational | Solved - 10/10/2025 |
| Missing zero-address check in transferOwnership() | Informational | Solved - 10/10/2025 |
| Fee conversion overflow because of large decimals from price feed | Informational | Solved - 10/10/2025 |
| Missing zero-address and role-existence validation in role management functions | Informational | Solved - 10/10/2025 |
| Cross-chain signature replay due to factory domain missing chainId | Informational | Solved - 10/10/2025 |
| EIP-712 signature replay possible in claim function due to missing nonce | Informational | Solved - 10/10/2025 |
| Missing amountStaked > 0 check allows unnecessary bonus logic execution | Informational | Solved - 10/10/2025 |
| Redundant lockup period validation | Informational | Solved - 10/10/2025 |
Halborn strongly recommends conducting a follow-up assessment of the project either within six months or immediately following any material changes to the codebase, whichever comes first. This approach is crucial for maintaining the project’s integrity and addressing potential vulnerabilities introduced by code modifications.
Table of Contents
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