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Steam-Fi Pre-Vault - Tea-Fi

Prepared by:

Halborn Logo

HALBORN

Last Updated 10/02/2025

Date of Engagement: September 15th, 2025 - September 23rd, 2025

Summary

100% of all REPORTED Findings have been addressed

All findings

11

Critical

0

High

0

Medium

2

Low

7

Informational

2

Table of Contents

1. Introduction

TeaFi engaged Halborn to conduct a security assessment on their smart contracts beginning on September 15th, 2025 and ending on September 23th, 2025. The scope of this assessment was limited to the smart contracts provided to the Halborn team. Commit hashes and additional details are documented in the Scope section of this report.


SteamFi Pre-Vaults manage user staking positions with modular StakingStrategy and RewardStrategy contracts, allowing flexible protocol integrations and reward logic. The system supports native/ERC-20 assets, on-behalf operations via EIP-712, and robust lifecycle management (stake → unstake → withdraw) with cooldowns, granular pause controls, and security safeguards.


2. Assessment Summary

Halborn was provided 7 days for the engagement and assigned 1 full-time security engineer to review the security of the smart contracts in scope. The engineer is a blockchain and smart contract security expert with advanced penetration testing and smart contract hacking skills, and deep knowledge of multiple blockchain protocols.


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, during the assessment Halborn identified several areas for improvement to reduce both the likelihood and impact of potential risks, which were mostly addressed by the TeaFi team. The primary suggestions include:

    • Decoupling the reward claiming mechanism from the withdrawal process to prevent permanent reward forfeiture.

    • Modify the reward calculation logic to account for the full period, ensuring users receive rewards until positions are actually withdrawn.

    • Update _receiveAssets() to refund excess ETH to msg.sender instead of from.

    • Implement a mechanism to track and close underlying protocol positions upon user withdrawal.

    • Replace manual price updates with automated oracle feeds to eliminate admin-triggered frontrunning opportunities.



3. Test Approach and Methodology

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 supply, withdraw, repay, and borrow, to validate expected behavior and identify edge-case vulnerabilities.

    • Local testing to simulate contract interactions and validate functional and security assumptions.

    • Local deployment and testing with Foundry.


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: contracts
(b) Assessed Commit ID: 7ccee89
(c) Items in scope:
  • contracts/SteamFiAaveStakingStrategy.sol
  • contracts/SteamFiMultiAssetStaticApyRewardStrategy.sol
  • contracts/SteamFiVault.sol
↓ Expand ↓
Out-of-Scope: Third party dependencies and economic attacks.
Remediation Commit ID:
  • cfbdd36
  • 314bf51
  • fe2b1c4
  • 5a5a9be
  • ffbd1a5
  • 21a5f26
  • 604355b
  • a48d85e
  • b636e45
Out-of-Scope: New features/implementations after the remediation commit IDs.

6. Assessment Summary & Findings Overview

Critical

0

High

0

Medium

2

Low

7

Informational

2

Security analysisRisk levelRemediation Date
Reward Forfeiture Due to Improper Vault Strategy IntegrationMediumSolved - 09/22/2025
Stale Price Oracle Vulnerability in Reward DistributionMediumRisk Accepted - 09/30/2025
User Withdrawals Leave Underlying Strategy Positions OpenLowRisk Accepted - 09/30/2025
Missing Weight Sum Validation in Reward DistributionLowSolved - 09/22/2025
Fee-on-Transfer Token Incompatibility in Staking Vault ContractLowSolved - 09/22/2025
Artificial APY Limitation Restricting Protocol FlexibilityLowSolved - 09/22/2025
No Check for Duplicate Reward Assets in addRewardAsset()LowSolved - 09/23/2025
Excess ETH Refund Can Be Redirected to Arbitrary User in SteamFiVault.sol::_receiveAssets()LowSolved - 09/25/2025
Decimal Precision Misconfiguration in Price ParametersLowSolved - 09/23/2025
Redundant ETH Refund Check in _receiveAssets()InformationalSolved - 09/23/2025
Centralization RiskInformationalSolved - 09/23/2025

7. Findings & Tech Details

7.1 Reward Forfeiture Due to Improper Vault Strategy Integration

//

Medium

Description
BVSS
Recommendation
Remediation Comment
Remediation Hash

7.2 Stale Price Oracle Vulnerability in Reward Distribution

//

Medium

Description
BVSS
Recommendation
Remediation Comment

7.3 User Withdrawals Leave Underlying Strategy Positions Open

//

Low

Description
BVSS
Recommendation
Remediation Comment

7.4 Missing Weight Sum Validation in Reward Distribution

//

Low

Description
BVSS
Recommendation
Remediation Comment
Remediation Hash

7.5 Fee-on-Transfer Token Incompatibility in Staking Vault Contract

//

Low

Description
BVSS
Recommendation
Remediation Comment
Remediation Hash

7.6 Artificial APY Limitation Restricting Protocol Flexibility

//

Low

Description
BVSS
Recommendation
Remediation Comment
Remediation Hash

7.7 No Check for Duplicate Reward Assets in addRewardAsset()

//

Low

Description
BVSS
Recommendation
Remediation Comment
Remediation Hash

7.8 Excess ETH Refund Can Be Redirected to Arbitrary User in SteamFiVault.sol::_receiveAssets()

//

Low

Description
BVSS
Recommendation
Remediation Comment
Remediation Hash

7.9 Decimal Precision Misconfiguration in Price Parameters

//

Low

Description
BVSS
Recommendation
Remediation Comment
Remediation Hash

7.10 Redundant ETH Refund Check in _receiveAssets()

//

Informational

Description
BVSS
Recommendation
Remediation Comment
Remediation Hash

7.11 Centralization Risk

//

Informational

Description
BVSS
Recommendation
Remediation Comment
Remediation Hash

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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