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Huma Protocol Update - Huma Finance

Prepared by:

Halborn Logo

HALBORN

Last Updated Unknown date

Date of Engagement: November 25th, 2024 - November 27th, 2024

Summary

0% of all REPORTED Findings have been addressed

All findings

4

Critical

0

High

0

Medium

0

Low

1

Informational

3

Table of Contents

1. Introduction

Huma engaged Halborn to conduct a security assessment on a set of changed in their Huma Protocol Solana program beginning on November 25th, 2024, and ending on November 27th, 2024. The security assessment was scoped to the Solana Program provided in huma-solana-programs GitHub repository. Commit hashes and further details can be found in the Scope section of this report.


The changes made to the protocol are intended to address the potential lack of redemption requests submissions by lenders when the lock-in period expires. To this end, a field, has been integrated, which allows the Sentinel service to submit the repayment request on behalf of lenders when activated, ensuring that this Sentinel service account cannot withdraw money on behalf of the user. Funds from processed refund requests will continue to be withdrawn by the lender.


An instruction has also been added to reallocate PoolConfig due to the size increase, and a padding field added to the end of the struct to account for future storage expansions.

2. Assessment Summary

Halborn was provided 3 days for the engagement and assigned two full-time security engineers to review the security of the Solana Programs in scope. The engineers are blockchain and smart contract security experts with advanced smart contract hacking skills, and deep knowledge of multiple blockchain protocols.

The purpose of the assessment is to:

    • Identify potential security issues within the Solana Programs.

    • Ensure that smart contract functionality operates as intended.

 

In summary, Halborn identified some improvements to reduce the likelihood and impact of risks, which should be addressed by the Huma team. The main ones were the following: 

    • Add a validation in the add_redemption_request instruction handler to ensure that the delegate and delegated amount meets the expectations.

    • Add a check in the add_redemption_request to ensure that the delegated amount meets the expected value when the flag is active.

    • Reallocate all existing pools to the new format to ensure seamless operations.

    • Allow the EA and pool treasury owner to call deposit without requiring delegation approval.

3. Test Approach and Methodology

Halborn performed a combination of a manual review of the source code and automated security testing to balance efficiency, timeliness, practicality, and accuracy in regard to the scope of the program assessment. While manual testing is recommended to uncover flaws in business logic, processes, and implementation; automated testing techniques help enhance coverage of programs 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.

    • Manual program source code review to identify business logic issues.

    • Mapping out possible attack vectors


    • Thorough assessment of safety and usage of critical Rust variables and functions in scope that could lead to arithmetic vulnerabilities.

    • Scanning dependencies for known vulnerabilities (

      cargo audit
      ).

    • Local runtime testing (

      anchor-test
      )

4. RISK METHODOLOGY

Every vulnerability and issue observed by Halborn is ranked based on two sets of Metrics and a Severity Coefficient. This system is inspired by the industry standard Common Vulnerability Scoring System.
The two Metric sets are: Exploitability and Impact. Exploitability captures the ease and technical means by which vulnerabilities can be exploited and Impact describes the consequences of a successful exploit.
The Severity Coefficients is designed to further refine the accuracy of the ranking with two factors: Reversibility and Scope. These capture the impact of the vulnerability on the environment as well as the number of users and smart contracts affected.
The final score is a value between 0-10 rounded up to 1 decimal place and 10 corresponding to the highest security risk. This provides an objective and accurate rating of the severity of security vulnerabilities in smart contracts.
The system is designed to assist in identifying and prioritizing vulnerabilities based on their level of risk to address the most critical issues in a timely manner.

4.1 EXPLOITABILITY

Attack Origin (AO):
Captures whether the attack requires compromising a specific account.
Attack Cost (AC):
Captures the cost of exploiting the vulnerability incurred by the attacker relative to sending a single transaction on the relevant blockchain. Includes but is not limited to financial and computational cost.
Attack Complexity (AX):
Describes the conditions beyond the attacker’s control that must exist in order to exploit the vulnerability. Includes but is not limited to macro situation, available third-party liquidity and regulatory challenges.
Metrics:
EXPLOITABILITY METRIC (mem_e)METRIC VALUENUMERICAL 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
Exploitability EE is calculated using the following formula:

E=∏meE = \prod m_e

4.2 IMPACT

Confidentiality (C):
Measures the impact to the confidentiality of the information resources managed by the contract due to a successfully exploited vulnerability. Confidentiality refers to limiting access to authorized users only.
Integrity (I):
Measures the impact to integrity of a successfully exploited vulnerability. Integrity refers to the trustworthiness and veracity of data stored and/or processed on-chain. Integrity impact directly affecting Deposit or Yield records is excluded.
Availability (A):
Measures the impact to the availability of the impacted component resulting from a successfully exploited vulnerability. This metric refers to smart contract features and functionality, not state. Availability impact directly affecting Deposit or Yield is excluded.
Deposit (D):
Measures the impact to the deposits made to the contract by either users or owners.
Yield (Y):
Measures the impact to the yield generated by the contract for either users or owners.
Metrics:
IMPACT METRIC (mIm_I)METRIC VALUENUMERICAL 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
Impact II is calculated using the following formula:

I=max(mI)+∑mI−max(mI)4I = max(m_I) + \frac{\sum{m_I} - max(m_I)}{4}

4.3 SEVERITY COEFFICIENT

Reversibility (R):
Describes the share of the exploited vulnerability effects that can be reversed. For upgradeable contracts, assume the contract private key is available.
Scope (S):
Captures whether a vulnerability in one vulnerable contract impacts resources in other contracts.
Metrics:
SEVERITY COEFFICIENT (CC)COEFFICIENT VALUENUMERICAL VALUE
Reversibility (rr)None (R:N)
Partial (R:P)
Full (R:F)		1
0.5
0.25
Scope (ss)Changed (S:C)
Unchanged (S:U)		1.25
1
Severity Coefficient CC is obtained by the following product:

C=rsC = rs

The Vulnerability Severity Score SS is obtained by:

S=min(10,EIC∗10)S = min(10, EIC * 10)

The score is rounded up to 1 decimal places.
SeverityScore Value Range
Critical9 - 10
High7 - 8.9
Medium4.5 - 6.9
Low2 - 4.4
Informational0 - 1.9

5. SCOPE

REPOSITORY
(a) Repository: huma-solana-programs
(b) Assessed Commit ID: https://github.com/00labs/huma-solana-programs/pull/113
(c) Items in scope:
  • huma/src/pool/instructions/update_pool_config.rs
  • huma/src/pool/states.rs
  • huma/src/tranche_vault/instructions/add_redemption_request.rs
↓ Expand ↓
Out-of-Scope: huma/src/common/calendar/*, huma/src/common/calendar.rs, huma/src/common/constants.rs, huma/src/common/errors.rs, huma/src/common/mod.rs, huma/src/common/preconditions.rs, huma/src/common/utils.rs, huma/src/common/huma_config/instructions/*, huma/src/common/huma_config/mod.rs, huma/src/common/huma_config/states.rs, huma/src/credit/*, huma/src/pool/epoch_manager.rs, huma/src/pool/mod.rs, huma/src/pool/pnl.rs, huma/src/pool/pool.rs, huma/src/pool/tranches_policy/*, huma/src/pool/tranches_policy.rs, huma/src/pool/instructions/admin_fees.rs, huma/src/pool/instructions/close_epoch.rs, huma/src/pool/instructions/close_pool.rs, huma/src/pool/instructions/create_pool.rs, huma/src/pool/instructions/create_pool_accounts.rs, huma/src/pool/instructions/disable_pool.rs, huma/src/pool/instructions/enable_pool.rs, huma/src/pool/instructions/mock_pnl.rs, huma/src/pool/instructions/mod.rs, huma/src/pool/instructions/pool_operator.rs, huma/src/tranche-vault/mod.rs, huma/src/tranche-vault/states.rs, huma/src/tranche-vault/tranche_vault.rs, huma/src/tranche-vault/instructions/, huma/src/tranche_vault/instructions/close_lender_accounts.rs, huma/src/tranche_vault/instructions/create_lender_accounts.rs, huma/src/tranche_vault/instructions/disburse.rs, huma/src/tranche_vault/instructions/make_initial_deposit.rs, huma/src/tranche_vault/instructions/manage_lender.rs, huma/src/tranche_vault/instructions/mod.rs, huma/src/tranche_vault/instructions/update_to_latest_redemption_record.rs, huma/src/tranche_vault/instructions/withdraw_after_pool_closure.rs, tranche-token-hook/src/constants.rs, tranche-token-hook/src/errors.rs, tranche-token-hook/src/lib.rs, tranche-token-hook/src/instructions/mod.rs, third party dependencies and economic attacks.
Out-of-Scope: New features/implementations after the remediation commit IDs.

6. Assessment Summary & Findings Overview

Critical

0

High

0

Medium

0

Low

1

Informational

3

Security analysisRisk levelRemediation Date
Reallocating pools with new format will let its data insconsistentLow-
Lack of delegated amount validation in add redemption requests for premature depositsInformational-
Potential denial of service if pools using non reallocated old format poolsInformational-
EA and treasury owner will also need to approve delegate if they want to call depositInformational-

7. Findings & Tech Details

7.1 Reallocating pools with new format will let its data insconsistent

//

Low

Description
BVSS
Recommendation

7.2 Lack of delegated amount validation in add redemption requests for premature deposits

//

Informational

Description
BVSS
Recommendation

7.3 Potential denial of service if pools using non reallocated old format pools

//

Informational

Description
BVSS
Recommendation

7.4 EA and treasury owner will also need to approve delegate if they want to call deposit

//

Informational

Description
BVSS
Recommendation

8. Automated Testing

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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Huma Protocol Update

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