Prepared by:
HALBORN
Last Updated 08/13/2025
Date of Engagement: July 15th, 2025 - July 29th, 2025
100% of all REPORTED Findings have been addressed
All findings
18
Critical
0
High
1
Medium
1
Low
3
Informational
13
Rho Labs engaged Halborn to perform a security assessment of their smart contracts from July 15th, 2025, to July 28th, 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 Rho Labs codebase in scope consists of a smart contract system for asset management, featuring ERC4626-compliant vaults, allocator and off-chain strategy vaults, a secure router for user and vault interactions, and robust access control. The system supports oracle-driven NAV reporting, and protocol-level controls for asset flows and permissions.
Halborn was allocated 10 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 several areas for improvement to reduce the likelihood and impact of potential risks, which were mostly addressed by the Rho Labs team. The primary recommendations were:
Replace vault.maxWithdraw(vaultAddress, vaultAddress, packages) with vault.maxWithdraw(address(this), address(this), packages) in _calcTotalSubVaultsAssets to ensure the calculation reflects the parent vault’s actual claim on the subVault’s assets.
Fund the vault with a meaningful initial deposit immediately after deployment and before allowing public deposits, ensuring a fair initial share/asset ratio.
Enforce at vault or ERC20Storage initialization that any asset marked as a wrapped native token has the same number of decimals as the native token for the deployment chain.
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
1
Medium
1
Low
3
Informational
13
| Security analysis | Risk level | Remediation Date |
|---|---|---|
| Incorrect address used during sub vaults asset calculation | High | Solved - 07/29/2025 |
| Share inflation attack possible in AllocatorVault with zero decimals offset | Medium | Risk Accepted - 08/07/2025 |
| Potential value mismatch when adding ERC20 and native token deposits | Low | Solved - 07/29/2025 |
| Zero address and zero ID insertion possible in IterableIdAddressSet | Low | Solved - 07/29/2025 |
| Decimals mismatch between parent and subVaults could break accounting | Low | Solved - 08/06/2025 |
| Insufficient input validation | Informational | Acknowledged - 07/30/2025 |
| Inconsistent role ID derivation reduces maintainability | Informational | Solved - 07/29/2025 |
| Unvalidated offset parameter in role address query | Informational | Solved - 07/29/2025 |
| Duplicated logic between previewDeposit and _previewDeposit can lead to inconsistencies | Informational | Solved - 08/06/2025 |
| Commented functionality | Informational | Solved - 07/29/2025 |
| Inconsistent use of uint alias instead of uint256 | Informational | Solved - 07/29/2025 |
| Floating pragma | Informational | Solved - 07/29/2025 |
| Suboptimal modifier ordering | Informational | Solved - 07/29/2025 |
| Unused functionality | Informational | Solved - 08/05/2025 |
| Use of revert strings instead of custom errors | Informational | Solved - 08/05/2025 |
| Unnecessary casting between uint and int increases code complexity and risk of subtle bugs | Informational | Solved - 08/05/2025 |
| Missing event | Informational | Solved - 08/05/2025 |
| Unused components | Informational | Solved - 08/05/2025 |
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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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Vault Contracts v2
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