AI Advisory
Strategic guidance for secure AI adoption
Prepared by:
HALBORN
Last Updated 07/01/2026
Date of Engagement: June 22nd, 2026 - June 22nd, 2026
100% of all REPORTED Findings have been addressed
All findings
5
Critical
0
High
0
Medium
0
Low
3
Informational
2
Nuva engaged Halborn to perform a security assessment of their smart contracts on June 22nd, 2026. 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 Nuva codebase in scope consists of a role-based, upgradeable oracle for setting and reading the nvToken share price plus a timelock controller that enforces minimum delays on proposed and executed governance actions.
Halborn was allocated 1 day 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 are to:
Identify potential security vulnerabilities within the smart contracts.
Verify that the smart contract functionality operates as intended.
In summary, Halborn identified several areas for improvement to reduce the likelihood and impact of security risks, which were totally addressed by the Nuva team. The main recommendations were:
Introduce a configurable maximum age (heartbeat) and have cgPricePerShare() revert when block.timestamp - lastUpdated exceeds it, and revert when no price has been set yet.
Consider implementing a role-based system for access control, transitioning control to a multi-signature wallet setup for critical functions such as setting the price, granting and revoking the pricing role, and authorizing upgrades, establishing community-driven governance for decision-making, and/or integrating time locks.
Grant DEFAULT_ADMIN_ROLE to the intended administrator during initialize() so that the inherited AccessControl management functions are usable and consistent with the ownership model.
Halborn conducted a combination of manual code review and automated security testing to balance efficiency, timeliness, practicality, and accuracy within the scope of this assessment. While manual testing is crucial for identifying flaws in logic, processes, and implementation, automated testing enhances coverage of smart contracts and quickly detects deviations from established security best practices.
The following phases and associated tools were employed throughout the term of the assessment:
Research into the platform's architecture, purpose and use.
Manual code review and walkthrough of smart contracts to identify any logical issues.
Comprehensive assessment of the safety and usage of critical Solidity variables and functions within scope that could lead to arithmetic-related vulnerabilities.
Local testing using custom scripts (Foundry).
Fork testing against main networks (Foundry).
Static security analysis of scoped contracts, and imported functions (Slither).
| 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
3
Informational
2
| Security analysis | Risk level | Remediation Date |
|---|---|---|
| Stale price served indefinitely due to missing freshness validation | Low | Solved - 06/25/2026 |
| Centralized oracle source and privileged control over price data | Low | Solved - 05/31/2026 |
| Permanent price feed lockout due to unguarded ownership renouncement | Low | Solved - 06/25/2026 |
| Timelock fully bypassable due to unvalidated zero minimum delay | Informational | Acknowledged - 06/26/2026 |
| Legacy storage gap pattern | Informational | Acknowledged - 06/26/2026 |
//Low
//Low
//Low
//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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Smart Contract Assessment
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