Trufin - Solana Staker Audit | TruYields

Summary

100% of all REPORTED Findings have been addressed

About this report

Assessment Type

Assurance Assessment

Date of Engagement

February 13th, 2025 - February 21st, 2025

Source Code

solana-staker-hb

Assessed Commit ID

a91e9b5

Severity Breakdown

0Solved
1Acknowledged
2Risk Accepted
3All Findings

Critical0
High0
Medium0
Low2
- 2Risk A.
Informational1
- 1Ack.

Introduction#

TruFin engaged Halborn to conduct a security assessment on their Staker Solana program beginning on February 14th, 2025, and ending on February, 26th, 2025. The security assessment was scoped to the Solana program provided in TruFin-io/solana-staker-hb GitHub repository. Commit hashes and further details can be found in the Scope section of this report.

The staker program is a staking vault solution built to streamline SOL staking - users deposit SOL into a stake pool and receive a reward-bearing token (TruSOL) which entitles them to redeem their staked SOL. The vault either lets users pick which validator to delegate their stake to or auto-manages validator allocations for enhanced performance.

To maintain compliance and security, every depositor must be allowlisted. The program checks a user's whitelist status at deposit time. In addition, the vault owner can pause deposits in emergencies, replace the stake manager authority, and add or remove validators from the pool.

Assessment Summary#

Halborn was provided 1 week, 4 days for the engagement and assigned one full-time security engineer to review the security of the Solana Program in scope. The engineer is a blockchain and smart contract security expert 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 staker Solana Program.
Ensure that the program's functionality operates as intended.

In summary, Halborn identified some improvements to reduce the likelihood and impact of risks, which were accepted and acknowledged by the TruFin team:

Explicitly verify the signer’s key is the owner’s key (rather than just any agent). [Risk Accepted]
Ensure that the InitializeStaker instruction is called by a trusted and known address, such as the program's upgrade authority. [Risk Accepted]
Require multiple signers in stake reallocation operations. [Acknowledged]

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 (solana-test-framework).

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 ( $m_e$ )	METRIC VALUE	NUMERICAL VALUE
Attack Origin (AO)	Arbitrary (AO:A)	1
Attack Origin (AO)	Specific (AO:S)	0.2
Attack Cost (AC)	Low (AC:L)	1
	Medium (AC:M)	0.67
	High (AC:H)	0.33
Attack Complexity (AX)	Low (AX:L)	1
	Medium (AX:M)	0.67
	High (AX:H)	0.33

Exploitability

E

is calculated using the following formula:

$E = \prod m_e$

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 ( $m_I$ )	METRIC VALUE	NUMERICAL VALUE
Confidentiality (C)	None (C:N)	0
	Low (C:L)	0.25
	Medium (C:M)	0.5
	High (C:H)	0.75
	Critical (C:C)	1
Integrity (I)	None (I:N)	0
	Low (I:L)	0.25
	Medium (I:M)	0.5
	High (I:H)	0.75
	Critical (I:C)	1
Availability (A)	None (A:N)	0
	Low (A:L)	0.25
	Medium (A:M)	0.5
	High (A:H)	0.75
	Critical (A:C)	1
Deposit (D)	None (D:N)	0
	Low (D:L)	0.25
	Medium (D:M)	0.5
	High (D:H)	0.75
	Critical (D:C)	1
Yield (Y)	None (Y:N)	0
	Low (Y:L)	0.25
	Medium (Y:M)	0.5
	High (Y:H)	0.75
	Critical (Y:C)	1

Impact

I

is calculated using the following formula:

$I = max(m_I) + \frac{\sum{m_I} - max(m_I)}{4}$

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 ( $C$ )	COEFFICIENT VALUE	NUMERICAL VALUE
Reversibility ( $r$ )	None (R:N)	1
	Partial (R:P)	0.5
	Full (R:F)	0.25
Scope ( $s$ )	Changed (S:C)	1.25
Scope ( $s$ )	Unchanged (S:U)	1

Severity Coefficient

C

is obtained by the following product:

$C = rs$

The Vulnerability Severity Score

S

is obtained by:

$S = min(10, EIC * 10)$

The score is rounded up to 1 decimal places.

Critical	High	Medium	Low	Informational
9 - 10	7 - 8.9	4.5 - 6.9	2 - 4.4	0 - 1.9

Scope#

(a) Repository:solana-staker-hb

(b) Assessed Commit ID:a91e9b54e2559d14f6a4ddecbe6ef8fabb954526

12 files

src

12 files

instructions

6 files

initialize.rs

rust

mod.rs

rust

setters.rs

rust

staking.rs

rust

validators.rs

rust

whitelist.rs

rust

state

3 files

events.rs

rust

mod.rs

rust

types.rs

rust

Out-of-Scope:Third-party dependencies and economic attacks.

Out-of-Scope: New features/implementations after the remediation commit IDs.

Assessment Summary & Findings Overview#

#	Title	Severity	Score	Status
HAL-01	Excessive trust assumption on Agents	Low	3.6	Risk Accepted03/03/2025
HAL-02	Staker initialization can be front-run	Low	3.1	Risk Accepted03/03/2025
HAL-03	Single-signature authority for stake reallocations	Informational	1.3	Acknowledged03/03/2025

Findings & Tech Details#

HAL-01Risk Accepted

Excessive trust assumption on Agents

Low

3.6AO:S/AC:L/AX:L/R:N/S:C/C:M/A:H/I:H/D:H/Y:HAO:S/AC:L/AX:L/R:N/S:C/C:M/A:H/I:H/D:H/Y:H

Description

Recommendation

Remediation Comment

HAL-02Risk Accepted

Staker initialization can be front-run

Low

3.1AO:A/AC:L/AX:L/R:N/S:C/C:N/A:N/I:L/D:N/Y:NAO:A/AC:L/AX:L/R:N/S:C/C:N/A:N/I:L/D:N/Y:N

Description

Recommendation

Remediation Comment

HAL-03Acknowledged

Single-signature authority for stake reallocations

Informational

1.3AO:S/AC:L/AX:L/R:N/S:U/C:N/A:N/I:N/D:M/Y:MAO:S/AC:L/AX:L/R:N/S:U/C:N/A:N/I:N/D:M/Y:M

Description

Recommendation

Remediation Comment

8. Automated Testing#

Disclaimer#

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.