Trufin - Solana Staker - TruYields

1. 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.

2. 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]

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 (solana-test-framework).