Prepared by:
HALBORN
Last Updated 08/27/2025
Date of Engagement: August 18th, 2025 - August 20th, 2025
100% of all REPORTED Findings have been addressed
All findings
4
Critical
0
High
0
Medium
0
Low
1
Informational
3
Moonwell engaged Halborn to conduct a security assessment on their smart contracts beginning on August 18th, 2025 and ending on August 19th, 2025. The security assessment was scoped to the smart contracts provided to the Halborn team. Commit hashes and further details can be found in the Scope section of this report.
The team at Halborn assigned one full-time security engineer to assess the security of the smart contracts. The security engineers are blockchain and smart-contract security experts with advanced penetration testing, smart-contract hacking, and deep knowledge of multiple blockchain protocols.
The purpose of this assessment is to:
Ensure that smart contract functions operate as intended.
Identify potential security issues with the smart contracts.
In summary, Halborn identified some improvements to reduce the likelihood and impact of risks, which were partially addressed by the Moonwell team. The main ones were the following:
Implement a two-step process where the owner nominates an account and the nominated account needs to call an acceptOwnership function for the transfer of the ownership to fully succeed.
Replace all revert strings with custom errors.
Add a zero-address check in the constructor, consistent with the setFeeCollector function.
Consider disallowing the owner address to be set to address(0).
Halborn performed a combination of manual review of the code and automated security testing to balance efficiency, timeliness, practicality, and accuracy in regard to the scope of the smart contract assessment. While manual testing is recommended to uncover flaws in logic, process, and implementation; automated testing techniques help enhance coverage of smart contracts and can quickly identify items that do not follow security best practices. The following phases and associated tools were used throughout the term of the assessment:
Research into the architecture, purpose, and use of the platform.
Smart contract manual code review and walkthrough to identify any logic issue.
Thorough assessment of safety and usage of critical Solidity variables and functions in scope that could lead to arithmetic related vulnerabilities.
Manual testing by custom scripts.
Graphing out functionality and contract logic/connectivity/functions (solgraph).
Static Analysis of security for scoped contract, and imported functions. (Slither).
Local or public testnet deployment (Foundry, Remix IDE).
| EXPLOITABILITY METRIC () | METRIC VALUE | NUMERICAL VALUE |
|---|---|---|
| Attack Origin (AO) | Arbitrary (AO:A) Specific (AO:S) | 1 0.2 |
| Attack Cost (AC) | Low (AC:L) Medium (AC:M) High (AC:H) | 1 0.67 0.33 |
| Attack Complexity (AX) | Low (AX:L) Medium (AX:M) High (AX:H) | 1 0.67 0.33 |
| IMPACT METRIC () | METRIC VALUE | NUMERICAL VALUE |
|---|---|---|
| Confidentiality (C) | None (C:N) Low (C:L) Medium (C:M) High (C:H) Critical (C:C) | 0 0.25 0.5 0.75 1 |
| Integrity (I) | None (I:N) Low (I:L) Medium (I:M) High (I:H) Critical (I:C) | 0 0.25 0.5 0.75 1 |
| Availability (A) | None (A:N) Low (A:L) Medium (A:M) High (A:H) Critical (A:C) | 0 0.25 0.5 0.75 1 |
| Deposit (D) | None (D:N) Low (D:L) Medium (D:M) High (D:H) Critical (D:C) | 0 0.25 0.5 0.75 1 |
| Yield (Y) | None (Y:N) Low (Y:L) Medium (Y:M) High (Y:H) Critical (Y:C) | 0 0.25 0.5 0.75 1 |
| SEVERITY COEFFICIENT () | COEFFICIENT VALUE | NUMERICAL VALUE |
|---|---|---|
| Reversibility () | None (R:N) Partial (R:P) Full (R:F) | 1 0.5 0.25 |
| Scope () | Changed (S:C) Unchanged (S:U) | 1.25 1 |
| Severity | Score Value Range |
|---|---|
| Critical | 9 - 10 |
| High | 7 - 8.9 |
| Medium | 4.5 - 6.9 |
| Low | 2 - 4.4 |
| Informational | 0 - 1.9 |
Critical
0
High
0
Medium
0
Low
1
Informational
3
| Security analysis | Risk level | Remediation Date |
|---|---|---|
| Missing zero-address validation for feeCollector | Low | Solved - 08/22/2025 |
| Use of Ownable library with single-step ownership transfer | Informational | Acknowledged - 08/22/2025 |
| Use of custom errors instead of revert strings | Informational | Acknowledged - 08/22/2025 |
| Owner can renounce ownership | Informational | Acknowledged - 08/22/2025 |
//Low
//Informational
//Informational
//Informational
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.
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