Prepared by:
HALBORN
Last Updated 12/18/2025
Date of Engagement: November 19th, 2025 - November 21st, 2025
100% of all REPORTED Findings have been addressed
All findings
6
Critical
0
High
1
Medium
0
Low
4
Informational
1
Mutuum Finance engaged Halborn to perform a security assessment of their EVM smart contracts from November 18th, 2025, to November 26th, 2025. The assessment scope was limited to the smart contracts provided to Halborn. Commit hashes and additional details are available in the Scope section of this report.
The Mutuum Finance codebase in scope consists of solidity smart contracts that implement an aave inspired staking mechanism with additional features like dynamic exchange rate, and revised slashing mechanism.
Halborn was allocated 7 days for this engagement and assigned 1 full-time security engineer to conduct a comprehensive review of the smart contracts within scope. The engineer is an expert in blockchain and smart contract security, with advanced skills in penetration testing and smart contract exploitation, as well as extensive knowledge of multiple blockchain protocols.
The objectives of this assessment were to:
Identify potential security vulnerabilities within the smart contracts.
Verify that the smart contract functionality operates as intended.
In summary, Halborn identified some areas for improvement to reduce the likelihood and impact of potential risks, which were mostly addressed by the Mutuum Finance team. The primary recommendations were as follows:
Consider modifying the stake function to make sure that zero shares should not be minted
Consider deriving totalStaked on-chain directly from the referenced staking token’s totalSupply wherever it is feasible.
Consider validating cooldownSeconds and unstakeWindow at pool creation time to ensure their sum stays within a safe bound.
Consider introducing bounds checks on the allowable range of expo + targetDecimals before computing the power of ten, reverting with a clear error if the combination would exceed a predefined maximum.
Halborn performed a combination of manual code review and automated security testing to balance efficiency, timeliness, practicality, and accuracy in regard to the scope of this assessment. While manual testing is essential to uncover flaws in logic, process, and implementation, automated testing techniques enhance coverage of smart contracts and can quickly identify issues that do not follow security best practices.
The following phases and associated tools were used throughout the assessment:
Research into the architecture, purpose, and use of the platform.
Manual code review and walkthrough of the smart contracts to identify potential logic issues.
Manual testing of all core functions, including deposit, withdraw, repay, and borrow, to validate expected behaviour and identify edge-case vulnerabilities.
Local testing to simulate contract interactions and validate functional and security assumptions using custom scripts (Foundry).
Local deployment and testing with Foundry.
| 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
1
Medium
0
Low
4
Informational
1
| Security analysis | Risk level | Remediation Date |
|---|---|---|
| First Depositor Share Price Manipulation Allows Theft of Future Deposits | High | Solved - 12/03/2025 |
| Reward Distribution Depends on Externally Supplied Value | Low | Risk Accepted - 12/03/2025 |
| Cooldown Underflow Risk with Extreme Parameters | Low | Solved - 12/03/2025 |
| Potential Overflow in Pyth Price Scaling for Extreme Exponents | Low | Solved - 12/03/2025 |
| No Explicit RewardToken Liquidity Check in Treasury | Low | Solved - 12/03/2025 |
| Ambiguity Around Units for Slashing Amounts | Informational | Solved - 12/03/2025 |
//High
//Low
//Low
//Low
//Low
//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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