The Vault - Directed Stake Program - The Vault

1. Introduction

The Vault team engaged Halborn to conduct a security assessment on their Directed Stake and Directed Stake Token Solana programs beginning on February 6th, 2025, and ending on February, 10th, 2025. The security assessment was scoped to the Solana programs provided in SolanaVault/directed-stake GitHub repository. Commit hashes and further details can be found in the Scope section of this report.

The directed-stake program provides core functionality for managing a "Director" account that encapsulates staking parameters and target configurations on Solana. By initializing a Director PDA, users or programs can set a specific stake target (like a validator's vote account) and later update or close that Director. The program uses standard Solana/Anchor pattern such as PDA derivations and cross-program invocations (CPIs).

The directed-stake-token program integrates token minting, burning and fee distribution into the directed staking workflow. It allows the creation of a specialized "DST" (directed stake token) mint, which represents a liquidity token for staked assets. Users can deposit vSOL (a liquid staking token) in exchange for newly minted DST tokens, or burn DST tokens to withdraw staked assets minus fees.

2. Assessment Summary

Halborn was provided 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 Co-Staking 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 partially addressed by The Vault team: 

• Add #[repr(packed)] or #[repr(C)] directly above any #[account(zero_copy)] struct definitions to ensure a stable field layout across all builds.

• Use checked SPL token methods for enhanced security and data integrity.

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).