Prepared by:
HALBORN
Last Updated 09/11/2025
Date of Engagement: July 22nd, 2025 - August 11th, 2025
100% of all REPORTED Findings have been addressed
All findings
7
Critical
0
High
2
Medium
1
Low
0
Informational
4
Bonzo Finance engaged Halborn to conduct a security assessment on their smart contracts beginning on July 22nd, 2025 and ending on August 11th, 2025. The security assessment was scoped to the smart contracts provided to Halborn. Commit hashes and further details can be found in the Scope section of this report.
The Bonzo Finance codebase in scope consists of different smart contracts, allowing users to generate yield on their assets, using underlying protocols like Uniswap and Aave forks. The contracts are forked from Beefy, with a good amount of modifications.
Halborn was provided 21 days for the engagement and assigned a full-time security engineer to review the security of the smart contracts in scope.
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 areas for improvement to reduce the likelihood and impact of potential risks, which were partially addressed by the Bonzo finance Team:
Handle conversions between assets correctly.
Handle precision properly when calculating pool prices.
Choose ticks according to the way Uniswap works to avoid DoS.
Avoid insecure use of 'slot0' for liquidity calculation to prevent sandwich attacks.
Prevent griefing attacks via 'permit' in 'stakeWithPermit'.
Ensure event arguments in '_harvest' are correct.
Correct looping approves to avoid an extra unnecessary iteration.
Halborn performed a manual review of the code. Manual testing is great to uncover flaws in logic, process, and implementation.
The following phases and associated tools were used throughout the term of the assessment:
Research into 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 led to arithmetic related vulnerabilities.
| 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
2
Medium
1
Low
0
Informational
4
| Security analysis | Risk level | Remediation Date |
|---|---|---|
| Incorrect sauce token conversions | High | Solved - 08/14/2025 |
| Pool price is computed incorrectly | High | Solved - 08/14/2025 |
| Wrong tick choice causes DoS of vault operations | Medium | Solved - 08/14/2025 |
| Liquidity calculation based on unvalidated slot0 price | Informational | Acknowledged - 08/21/2025 |
| Griefing Attack via permit in stakeWithPermit | Informational | Solved - 08/21/2025 |
| Looping approves for 1 extra iteration | Informational | Acknowledged - 08/14/2025 |
| Incorrect Event Argument in _harvest | Informational | Solved - 08/21/2025 |
//High
//High
//Medium
//Informational
//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.
// Download the full report
Beefy Hedera Contracts
* Use Google Chrome for best results
** Check "Background Graphics" in the print settings if needed
