The Hacken 2025 Yearly Security ReportCovers major Web3 breaches, their root causes, prevention insights, and key regulatory trends for 2026.
Learn more

0x0

Audit name:

[SCA] 0x0 | Relayer Manager | Aug2024

Date:

Aug 23, 2024

Table of Content

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

Want a comprehensive audit report like this?

Introduction

We express our gratitude to the 0x0 team for the collaborative engagement that enabled the execution of this Smart Contract Security Assessment.

RelayerManager is a contract within the 0x0 project that manages and regulates relayers responsible for executing token transfers within the Arcane ecosystem.

Document

NameSmart Contract Code Review and Security Analysis Report for 0x0
Audited ByKornel Światłowski
Approved ByPrzemyslaw Swiatowiec
Websitehttps://0x0.ai/→
Changelog12/08/2024 - Preliminary Report; 23/08/2024 - Final Report
PlatformEthereum
LanguageSolidity
TagsSignatures, Upgradable
Methodologyhttps://hackenio.cc/sc_methodology→

  • Document

    Name
    Smart Contract Code Review and Security Analysis Report for 0x0
    Audited By
    Kornel Światłowski
    Approved By
    Przemyslaw Swiatowiec
    Website
    https://0x0.ai/→
    Changelog
    12/08/2024 - Preliminary Report; 23/08/2024 - Final Report
    Platform
    Ethereum
    Language
    Solidity
    Tags
    Signatures, Upgradable
    Methodology
    https://hackenio.cc/sc_methodology→

Review Scope

Repositoryhttps://github.com/0x0exchange/arcane→
Commit46807d32150283a9007429c0f9f9e03990071694

Audit Summary

11Total Findings
11Resolved
0Accepted
0Mitigated

The system users should acknowledge all the risks summed up in the risks section of the report

Documentation quality

  • Functional requirements have some gaps.

  • Technical description has some gaps.

Code quality

  • The development environment is configured.

Test coverage

Code coverage of the project is 95.31% (branch coverage).

  • Deployment and basic user interactions are covered with tests.

  • Negative cases coverage is missed.

System Overview

The RelayerManager contract manages and regulates relayers responsible for executing token transfers within the Arcane ecosystem. It enforces strict requirements, including token balance thresholds, to ensure only qualified relayers can operate. The contract allows for registering, activating, deactivating, and permanently disabling relayers, while also verifying signatures to ensure the authenticity of each transfer. It supports both single and multiple transfer modes and manages fees, which can be paid in tokens or ETH. The contract integrates with the Arcane contract to handle token transfers.

Privileged roles

The system uses OwnableUpgradeable library from OpenZeppelin to restrict access to key functions. The contract owner can:

  • Sets the arcane contract address

  • Sets the maximum number of relayers per owner

  • Withdraws ETH from the contract

  • Withdraws tokens from the contract

Risks

Flexibility and Risk in Contract Upgrades: The project's contracts are upgradable, allowing the administrator to update the contract logic at any time. While this provides flexibility in addressing issues and evolving the project, it also introduces risks if upgrade processes are not properly managed or secured, potentially allowing for unauthorized changes that could compromise the project's integrity and security.

Absence of Upgrade Window Constraints: The contract suite allows for immediate upgrades without a mandatory review or waiting period, increasing the risk of rapid deployment of malicious or flawed code, potentially compromising the system's integrity and user assets.

Scope Definition and Security Guarantees: The audit does not cover all code in the repository. Contracts outside the audit scope may introduce vulnerabilities, potentially impacting the overall security due to the interconnected nature of smart contracts.

System Reliance on External Contracts: The functioning of the system significantly relies on specific external contracts. Any flaws or vulnerabilities in these contracts adversely affect the audited project, potentially leading to security breaches or loss of funds.

Findings

Code
―
Title
Status
Severity
F-2024-4869The Usage of the Precompile ecrecover Can Lead to Signature Mailability
fixed

Medium
F-2024-5204Possible Signature Replay Attack: Missing Chain Id In The Signature
fixed

Low
F-2024-5158Missing Validation of Return Values in relayTransfer Function
fixed

Observation
F-2024-4873Use of transfer() Instead of call() to Send Native Tokens
fixed

Observation
F-2024-4871Missing Events For Critical Actions
fixed

Observation
F-2024-4867Some Public Functions Should Be Declared As External
fixed

Observation
F-2024-4866Redundant Imports
fixed

Observation
F-2024-4864Missing Two-step Ownership Transfer Process
fixed

Observation
F-2024-4863Development Libraries Import in the Production Ready Contract
fixed

Observation
F-2024-4861Gas Inefficiency Due to Missing Usage of Solidity Custom Errors
fixed

Observation
1-10 of 11 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/0x0exchange/arcane→
Commit46807d32150283a9007429c0f9f9e03990071694
Whitepaperhttps://docs.0x0.ai/→
RequirementsREADME.md
Technical RequirementsREADME.md

Contracts in Scope

contracts
RelayerManager.sol - contracts › RelayerManager.sol

Disclaimer

0x0 audit by Hacken