Audit name:
[SCA] CREO Engine | Bridge | Mar2024
Date:
Apr 3, 2024
Table of Content
Introduction
We express our gratitude to the CREO team for the collaborative engagement that enabled the execution of this Smart Contract Security Assessment.
Creo Engine is a private bridge solution.
| title | content |
|---|---|
| Platform | Ethereum |
| Language | Solidity |
| Tags | ERC20, Bridge |
| Timeline | 11/03/2024 - 03/04/2024 |
| Methodology | https://hackenio.cc/sc_methodology→ |
Review Scope | |
|---|---|
| Repository | https://github.com/creoenginecto/creobridge→ |
| Commit | c7d6502 |
Review Scope
- Commit
- c7d6502
Audit Summary
10/10
100%
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 CREO |
| Audited By | Turgay Arda Usman |
| Approved By | Grzegorz Trawinski |
| Website | - |
| Changelog | 15/03/2024 - Preliminary Report && 02/04/2024 Final Report |
Document
- Name
- Smart Contract Code Review and Security Analysis Report for CREO
- Audited By
- Turgay Arda Usman
- Approved By
- Grzegorz Trawinski
- Website
- -
- Changelog
- 15/03/2024 - Preliminary Report && 02/04/2024 Final Report
System Overview
Creo is a private bridge with the following contracts:
CreoEngine — simple ERC-20 token burnable token that mints all initial supply to a deployer. Additional minting is not allowed.
It has the following attributes:
Decimals: 18
BridgeAssist — a contract that creates incoming and outgoing transaction instances for the bridge. It also handles fees.
Privileged roles
An admin can change the bridge parameters and withdraw funds from the bridge. Admins should be able to add more admins. The role can also be renounced and transferred to another wallet.
There can be multiple relayers. A relayer can prove that the bridge operation has been initiated and funds have been locked on the sending chain. The role can be granted and revoked by admins.
Executive Summary
Documentation quality
The total Documentation Quality score is 10 out of 10.
Functional requirements are provided .
Technical description is provided.
Code quality
The total Code Quality score is 10 out of 10.
The code follows best practices and style guides
The development environment is configured.
Test coverage
Code coverage of the project is 100.00% (branch coverage).
Deployment and basic user interactions are covered with tests.
Negative cases coverage is adequate .
Interactions by several users are tested thoroughly.
Security score
Upon auditing, the code was found to contain 0 critical, 0 high, 0 medium, and 0 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 10. This score reflects the combined evaluation of documentation, code quality, test coverage, and security aspects of the project.
Risks
The provided documentation states that the system will allow Multicall, which allows users to provide integration via ERC2771. ERC2711 contains a multicall issue which allows a malicious user to send transactions by using any role or user. Since the audit scope is a part of a bigger system this vulnerability can harm the system.
The exchange rates used in the system are being determined by the manager, which creates the possibility of these rates being outdated. This can prevent users benefitting from the latest rates.
Findings
Code ― | Title | Status | Severity | |
|---|---|---|---|---|
| F-2024-1535 | EIP712 signatures are not single use and not time limitted | mitigated | Observation | |
| F-2024-1468 | Checks Effects Interactions Pattern Violation | fixed | Observation | |
| F-2024-1467 | Missing Zero Address Violation | 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/creoenginecto/creobridge→ |
| Commit | c7d6502 |
| Whitepaper | - |
| Requirements | Provided as a File |
| Technical Requirements | Provided as a File |
Scope Details
- Commit
- c7d6502
- Whitepaper
- -
- Requirements
- Provided as a File
- Technical Requirements
- Provided as a File