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- [SCA] Octopus Bridge | BTC Bridge Contracts | May2024
Audit name:
[SCA] Octopus Bridge | BTC Bridge Contracts | May2024
Date:
Jun 1, 2024
Table of Content
Introduction
We express our gratitude to the Octopus Bridge team for the collaborative engagement that enabled the execution of this Smart Contract Security Assessment.
The Bridge contract is designed to facilitate cross-network token transfers. It provides mechanisms for depositing tokens on one chain and withdrawing them on another, leveraging the security features of the Solidity language and OpenZeppelin's smart contract standards.
| title | content |
|---|---|
| Platform | EVM |
| Language | Solidity |
| Tags | Bridge |
| Timeline | 14/05/2024 - 20/05/2024 |
| Methodology | https://hackenio.cc/sc_methodology→ |
Review Scope | |
|---|---|
| Repository | https://github.com/LucasWongC/btc-bridge-contracts→ |
| Commit | e0cf731 |
Review Scope
- Commit
- e0cf731
Audit Summary
10/10
31.82%
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 Octopus Bridge |
| Audited By | Kaan Caglan |
| Approved By | Przemyslaw Swiatowiec |
| Website | https://octopusbridge.xyz/→ |
| Changelog | 20/01/2024 - Preliminary Report |
Document
- Name
- Smart Contract Code Review and Security Analysis Report for Octopus Bridge
- Audited By
- Kaan Caglan
- Approved By
- Przemyslaw Swiatowiec
- Website
- https://octopusbridge.xyz/→
- Changelog
- 20/01/2024 - Preliminary Report
System Overview
The Bridge contract is designed to facilitate cross-network token transfers. It provides mechanisms for depositing tokens on one chain and withdrawing them on another, leveraging the security features of the Solidity language and OpenZeppelin's smart contract standards.
Contracts
Bridge.sol:
Inherits: AccessControl, ReentrancyGuard
Purpose: Manages the cross-chain transfer of tokens using deposit and withdrawal functions.
Privileged Roles
Admin Role:
Capabilities: Can grant and revoke the KEEPER_ROLE, add pools of tokens, and withdraw tokens from pools.
Assigned to: The admin address provided at contract initialization.
Keeper Role:
Capabilities: Can process withdrawals initiated by users and verify deposit signatures.
Granted By: Admin role, which also sets the role's administration to itself.
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.
Best practices are applied.
Test coverage
Code coverage of the project is 31.82 %(branch coverage)
Not all branches are covered with tests.
Security score
Upon auditing, the code was found to contain 1 critical, 0 high, 2 medium, and 0 low severity issues. Out of these, 3 issues have been addressed and resolved, 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
Single Points of Failure and Control: The project is fully or partially centralized, introducing single points of failure and control. This centralization can lead to vulnerabilities in decision-making and operational processes, making the system more susceptible to targeted attacks or manipulation.
Administrative Key Control Risks: The digital contract architecture relies on administrative keys for critical operations. Centralized control over these keys presents a significant security risk, as compromise or misuse can lead to unauthorized actions or loss of funds.
Missing Test Cases: The contract does not have enough proper unit test cases.
Findings
ecrecover Is Susceptible To Signature MalleabilityimmutableCode ― | Title | Status | Severity | |
|---|---|---|---|---|
| F-2024-2997 | Signature Replay Attack | fixed | Critical | |
| F-2024-2994 | Use Of ecrecover Is Susceptible To Signature Malleability | fixed | Medium | |
| F-2024-2992 | Contracts Are Vulnerable To Fee-On-Transfer Accounting-Related Issues | fixed | Medium | |
| F-2024-2904 | State Variables Only Set in The Constructor Should Be Declared immutable | fixed | Observation | |
| F-2024-2903 | Floating Pragma | accepted | 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/LucasWongC/btc-bridge-contracts→ |
| Commit | e0cf7313ff168e95c6d317a8ddcd1c149c916c48 |
| Whitepaper | N/A |
| Requirements | N/A |
| Technical Requirements | N/A |
Scope Details
- Commit
- e0cf7313ff168e95c6d317a8ddcd1c149c916c48
- Whitepaper
- N/A
- Requirements
- N/A
- Technical Requirements
- N/A