Introduction
We express our gratitude to the BlockSquare team for the collaborative engagement that enabled the execution of this Smart Contract Security Assessment.
The Blocksquare Revenue Distribution System is an innovative smart contract ecosystem, specifically designed for managing and distributing revenue in a property management or real estate investment context.
| title | content |
|---|---|
| Platform | EVM |
| Language | Solidity |
| Tags | Airdrop; Proxy; Upgradable |
| Timeline | 24/01/2024 - 20/02/2024 |
| Methodology | https://hackenio.cc/sc_methodology→ |
Review Scope | |
|---|---|
| Repository | https://github.com/blocksquare/blocksquare-contracts→ |
| Commit | 61b77c4 |
Review Scope
- Commit
- 61b77c4
Audit Summary
10/10
96.15%
10/10
10/10
The system users should acknowledge all the risks summed up in the risks section of the report
Document Information
This report may contain confidential information about IT systems and the intellectual property of the Customer, as well as information about potential vulnerabilities and methods of their exploitation.
The report can be disclosed publicly after prior consent by another Party. Any subsequent publication of this report shall be without mandatory consent.
Document | |
|---|---|
| Name | Smart Contract Code Review and Security Analysis Report for BlockSquare |
| Audited By | Ivan Bondar |
| Approved By | Grzegorz Trawinski |
| Website | https://blocksquare.io/→ |
| Changelog | 26/01/2024 - Preliminary Report |
| 20/02/2024 - Final Report |
Document
- Name
- Smart Contract Code Review and Security Analysis Report for BlockSquare
- Audited By
- Ivan Bondar
- Approved By
- Grzegorz Trawinski
- Website
- https://blocksquare.io/→
- Changelog
- 26/01/2024 - Preliminary Report
- 20/02/2024 - Final Report
System Overview
The Blocksquare Revenue Distribution System is an innovative smart contract ecosystem built on Ethereum, specifically designed for managing and distributing revenue in a property management or real estate investment context. It centralizes the revenue management process for property-related investments, offering a transparent and efficient way to handle revenue distributions and claims.
The files in the scope:
RevenueDistribution.sol - this contract is central to the system, facilitating various functionalities:
Revenue Tracking and Distribution:
Manages revenue associated with different properties (PropTokens).
Tracks individual and total revenue amounts for properties and users.
Enables the addition of revenue for properties and its distribution among multiple users.
Revenue Claiming:
Provides functions for users to claim revenue for specific properties or multiple properties.
Supports claiming for individual and multiple wallets.
Data and Token Integration:
Interacts with external contracts/interfaces indicated by data (for permissions) and tokenAddress (for token transfers).
RevenueDistributionProxy.sol - a Transparent Upgradeable Proxy that serves as a flexible and upgradable front for the RevenueDistribution contract
Privileged roles
RevenueDistribution:
Contract Owner:
Has the authority to transfer ownership and renounce ownership.
Can update the data proxy (_data) address, affecting the system's core functionalities.
Authorized Users:
Users with special permissions (verified through the _data contract) can add revenue to the system.
This role is restricted to system administrators or trusted community partners.
RevenueDistributionProxy:
Proxy Admin:
Responsible for managing and executing upgrades to the RevenueDistribution contract.
Holds significant power over the proxy contract, with the ability to change the business logic address (logic) and initialize new logic contracts.
Executive Summary
Documentation quality
The total Documentation Quality score is 10 out of 10.
Functional requirements have some gaps:
Project overview is detailed
The roles within the system are described.
Use cases are described and detailed.
For each contract all futures are described
All interactions are described.
Technical description is robust:
Run instructions are provided.
Technical specification is provided.
NatSpec is sufficient.
Code quality
The total Code Quality score is 10 out of 10.
The development environment is configured.
Test coverage
Code coverage of the project is 96.15% (branch coverage).
Deployment and basic user interactions are covered with tests.
Negative cases coverage is present.
Interactions by several users are tested.
Security score
Upon auditing, the code was found to contain 0 critical, 0 high, 2 medium, and 2 low severity issues. All issues were fixed in the remediation part of this audit, leading to a security score of 10 out of 10.
All identified issues are detailed in the “Findings” section of this report.
Summary
The comprehensive audit of the customer's smart contract yields an overall score of 9.9. This score reflects the combined evaluation of documentation, code quality, test coverage, and security aspects of the project.
Risks
Upgradability and Future Version Modifications: The contract's upgradable nature means that its implementation can be modified in future versions. This flexibility allows for necessary updates and improvements but also introduces uncertainty for users regarding future changes in the contract's behavior and rules. Users should stay informed about any contract upgrades and understand their implications.
Criticality of Accurate Revenue Allocation in addRevenue Function: The addRevenue function plays a crucial role in distributing revenues accurately among users. It requires precise input parameters to ensure fair and correct allocation. Incorrect or manipulated inputs can lead to improper revenue distribution, affecting the trust and fairness of the system. Users and community partners must exercise due diligence in verifying the accuracy of the input data.
Changeability of Access Control via RevenueDistributionHelpers _data: The contract allows for the modification of the RevenueDistributionHelpers _data, which controls access permissions, particularly for the addRevenue function. Changes to this helper can alter who has the authority to distribute revenues, potentially impacting the consistency and integrity of revenue allocations. Users should be aware of any changes to these access controls and understand their potential impact on revenue distribution practices.
Solidity Version Compatibility and Cross-Chain Deployment: The project utilizes Solidity version 0.8.20 or higher, which includes the introduction of the PUSH0 (0x5f) opcode. This opcode is currently supported on the Ethereum mainnet but may not be universally supported across other blockchain networks. Consequently, deploying the contract on chains other than the Ethereum mainnet, such as certain Layer 2 (L2) chains or alternative networks, might lead to compatibility issues or execution errors due to the lack of support for the PUSH0 opcode. In scenarios where deployment on various chains is anticipated, selecting an appropriate Ethereum Virtual Machine (EVM) version that is widely supported across these networks is crucial to avoid potential operational disruptions or deployment failures.
Findings
address(0) Code ― | Title | Status | Severity | |
|---|---|---|---|---|
| F-2024-0583 | Token Address Alteration in Revenue Distribution Contract | fixed | Medium | |
| F-2024-0579 | Incompatibility with Non-Standard ERC20 Token Interfaces | fixed | Medium | |
| F-2024-0575 | Checks-Effects-Interactions Pattern Violation | fixed | Low | |
| F-2024-0570 | Inadequate Constructor Initialization in Upgradeable Contract | fixed | Low | |
| F-2024-0591 | SPDX License Identifier | fixed | Observation | |
| F-2024-0582 | Unnecessary Revenue Transfer for Zero Amount | fixed | Observation | |
| F-2024-0580 | Redundant Zero Address Check in Contract Initialization | fixed | Observation | |
| F-2024-0576 | Missing checks for address(0) | fixed | Observation | |
| F-2024-0574 | Public Functions That Should Be External | fixed | Observation | |
| F-2024-0573 | Function Parameter "owner" Shadows Function owner() from OwnableUpgradeable Contract | fixed | Observation |
Appendix 1. Severity Definitions
When auditing smart contracts, Hacken is using a risk-based approach that considers Likelihood, Impact, Exploitability and Complexity metrics to evaluate findings and score severities.
Reference on how risk scoring is done is available through the repository in our Github organization:
Severity | Description |
|---|---|
Critical | Critical vulnerabilities are usually straightforward to exploit and can lead to the loss of user funds or contract state manipulation. |
High | High vulnerabilities are usually harder to exploit, requiring specific conditions, or have a more limited scope, but can still lead to the loss of user funds or contract state manipulation. |
Medium | Medium vulnerabilities are usually limited to state manipulations and, in most cases, cannot lead to asset loss. Contradictions and requirements violations. Major deviations from best practices are also in this category. |
Low | Major deviations from best practices or major Gas inefficiency. These issues will not have a significant impact on code execution, do not affect security score but can affect code quality score. |
Severity
- Critical
Description
- Critical vulnerabilities are usually straightforward to exploit and can lead to the loss of user funds or contract state manipulation.
Severity
- High
Description
- High vulnerabilities are usually harder to exploit, requiring specific conditions, or have a more limited scope, but can still lead to the loss of user funds or contract state manipulation.
Severity
- Medium
Description
- Medium vulnerabilities are usually limited to state manipulations and, in most cases, cannot lead to asset loss. Contradictions and requirements violations. Major deviations from best practices are also in this category.
Severity
- Low
Description
- Major deviations from best practices or major Gas inefficiency. These issues will not have a significant impact on code execution, do not affect security score but can affect code quality score.
Appendix 2. Scope
The scope of the project includes the following smart contracts from the provided repository:
Scope Details | |
|---|---|
| Repository | https://github.com/blocksquare/blocksquare-contracts→ |
| Commit | dbb42e8598c4c03d0879f4c7f03c5f717b613ba0 |
| Whitepaper | N/A |
| Requirements | NatSpec |
| Technical Requirements | https://docs.blocksquare.io/for-developers/revenue-distribution-contract→ |
Scope Details
- Commit
- dbb42e8598c4c03d0879f4c7f03c5f717b613ba0
- Whitepaper
- N/A
- Requirements
- NatSpec
- Technical Requirements
- https://docs.blocksquare.io/for-developers/revenue-distribution-contract→