Q1 2026 Security & Compliance Report44 incidents, $482M in losses, insights from 11 industry leaders.
Read the report
Ethereum Towers logo

Ethereum Towers

Audit name:

[SCA] Ethereum Towers | Staking | Jun2022

Date:

Jul 2, 2022

Table of Content

→Introduction
→Audit Summary
→Document Information
→System Overview
→Executive Summary
→Risks
→Findings
→Appendix 1. Severity Definitions
→Appendix 2. Scope
→Disclaimer

Want a comprehensive audit report like this?

Introduction

We express our gratitude to the Ethereum Towers team for the collaborative engagement that enabled the execution of this Smart Contract Security Assessment.

Ethereum Towers is a community-centric, vertical megastructure consisting of 4,388 resident-owned apartments and a variety of communal areas, set in the forthcoming Ethereum Worlds Metaverse.

titlecontent
PlatformEVM
LanguageSolidity
TagsStaking
Timeline16/06/2022 - 04/07/2022
Methodologyhttps://hackenio.cc/sc_methodology→

    Review Scope

    Repositoryhttps://github.com/ethereumtowers/contracts→
    Commit94eb48031a02455bb3c48285ffe41fbbe3498079

    Audit Summary

    Total9.9/10
    Security Score

    10/10

    Test Coverage

    10/10

    Code Quality Score

    9/10

    Documentation Quality Score

    10/10

    6Total Findings
    5Resolved
    0Accepted
    0Mitigated

    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

    NameSmart Contract Code Review and Security Analysis Report for Ethereum Towers
    Audited ByHacken
    Websitehttps://ethereumtowers.com→
    Changelog17/06/2022 - Initial Review
    04/07/2022 - Second Review

    • Document

      Name
      Smart Contract Code Review and Security Analysis Report for Ethereum Towers
      Audited By
      Hacken
      Website
      https://ethereumtowers.com→
      Changelog
      17/06/2022 - Initial Review
      04/07/2022 - Second Review

    System Overview

    Ethereum Towers is a community-centric, vertical megastructure consisting of 4,388 resident-owned apartments and a variety of communal areas, set in the forthcoming Ethereum Worlds Metaverse with the following contracts:

    • EthereumWorldsNFTStaking — a contract that rewards users for staking their NFTs. Rewards are calculated off-chain.

    Privileged roles

    • The owner of the EthereumWorldsNFTStaking contract can pause staking, unstacking, and claiming in case of emergency.

    • The owner of the EthereumWorldsNFTStaking contract can update the service signer address.

    • The owner of the EthereumWorldsNFTStaking contract can update the max amount of tokens in staking.

    • The owner of the EthereumWorldsNFTStaking contract can withdraw ERC20 tokens sent to the contract.

    Executive Summary

    Documentation quality

    The total Documentation quality score is 10 out of 10.

    • Functional and technical requirements are provided.

    • Whitepaper describes the project adequately.

    Code quality

    The total Code quality score is 9 out of 10.

    • Code style and naming conventions are respected.

    • The “should restrict calling stake for non-existing token” test is failing and should be fixed.

    Architecture quality

    The Architecture quality score is 10 out of 10.

    • Contracts follow single responsibility principles.

    • Code is well-formatted.

    Security score

    Upon auditing, the code was found to contain 0 critical, 1 high, 1 medium, and 4 low severity issues, 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, architecture quality, and security aspects of the project.

    Scoring Methodologyarrow right

    Risks

    In case of an admin keys leak, an attacker can lock contract functionality.

    In case the contract will not be funded with world tokens - it would not be possible to claim rewards.

    Findings

    Code
    ―
    Title
    Status
    Severity
    F-2022-1589Inconsistent contract state
    fixed

    High
    F-2022-1590Unused renting logic
    fixed

    Medium
    F-2022-1594Redundant SafeCast library
    unfixed

    Low
    F-2022-1593Zero address is allowed
    fixed

    Low
    F-2022-1592Missing events arithmetic
    fixed

    Low
    F-2022-1591Variable Shadowing
    fixed

    Low
    1-6 of 6 findings

    Identify vulnerabilities in your smart contracts.

    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

    Repositoryhttps://github.com/ethereumtowers/contracts→
    Commit94eb48031a02455bb3c48285ffe41fbbe3498079
    WhitepaperProvided→
    RequirementsProvided
    Technical RequirementsProvided→

    Contracts in Scope

    contracts
    staking
    EthereumWorldsNFTStaking.sol - contracts › staking › EthereumWorldsNFTStaking.sol

    Disclaimer