Coinbase Smart Wallet - MSK's results

Smart Wallet Analysis Report

Table of Contents

1. Executive Summary
2. Introduction
3. Methodology
4. Contract Overview 4.1. MagicSpend.sol 4.2. SmartWallet 4.3. ERC1271.sol 4.4. CoinbaseSmartWallet.sol 4.5. CoinbaseSmartWalletFactory.sol 4.6. MultiOwnable.sol 4.7. FCL.sol
5. Analysis 5.1. Medium Risk Issues 5.2. Low Risk Issues
6. Potential Attack Surfaces
7. Recommendations for Mitigation
8. Systemic Risks and Architectural Weaknesses

1. Executive Summary

A security analysis of the smart contract project reveals various vulnerabilities in seven core contracts ranging from moderate to low risk. Medium-risk concerns mainly concern centralization and mishandling of token transfers, which could lead to significant loss of assets or unauthorized control over contracts. Low-risk issues, such as the absence of a two-step transfer of ownership and potential replay attacks, pose less immediate but still worrisome risks. This report offers a comprehensive overview of these vulnerabilities, assesses potential attacks, and suggests detailed mitigation strategies to improve a project's security posture. In addition, it highlights system risks and architectural flaws.

2. Introduction

This project consists of a set of smart contracts designed to facilitate various blockchain operations, from financial transactions to multi-owner management. Due to the critical nature of these operations, contracts must adhere to the highest security standards to prevent malicious activity and ensure the integrity of transactions. The goal of this analysis is to systematically identify and evaluate vulnerable points within the project, evaluate related risks and propose appropriate solutions to effectively mitigate these risks. The ultimate goal is to strengthen the project's security mechanisms and architectural design to withstand current and future blockchain threats.

3. Methodology

The Analysis process spanned 16 hours, i starting with a deep dive into the contract architecture followed by examination of the code for problems & concluding with risks & recommendations.

4. Contract Overview

4.1. MagicSpend.sol

This contract is essential to the project's financial operations and enables transactions and transfers of ownership. A key feature is its ability to process deposits and withdrawals, which requires robust security mechanisms to prevent unauthorized access and ensure transaction integrity.

4.2. SmartWallet

The SmartWallet suite contains contracts that manage user wallets and enable secure storage and transfer of assets. These contracts must be robust against attacks to protect user resources and maintain trust in the system.

4.3. ERC1271.sol

ERC1271.sol serves as a signature verification standard and plays a key role in validating transactions and interactions within the ecosystem, which requires strict security measures to prevent forgery and unauthorized actions.

4.4. CoinbaseSmartWallet.sol

This contract integrates with Coinbase, provides wallet services, and highlights the project's dependence on external platforms. Security in this integration is paramount to avoid exposing vulnerabilities in one system to another.

4.5. CoinbaseSmartWalletFactory.sol

This contract factory, which is responsible for instantiating the CoinbaseSmartWallet, underscores the importance of secure deployment mechanisms to prevent malicious or faulty wallets from being instantiated.

4.6. MultiOwnable.sol

It introduces a multi-owner model that divides control among several parties to mitigate the risks associated with single-owner control. The design of this contract must prevent collusion and ensure that no party can compromise the system.

4.7. FCL.sol

FCL.sol, the core library providing common functionality used throughout the project, must be secure and reliable, as vulnerabilities here can affect multiple contracts and operations.

5. Analysis

5.1. Medium Risk Issues Centralization Risk for Trusted Owners Files: MagicSpend.sol, MultiOwnable.sol Issue: High centralization in admin functions. Code Snippet:

function addOwnerAddress(address owner) public virtual onlyOwner {

Reduce centralization through decentralized governance mechanisms.

5.2. Low Risk Issues File: MagicSpend.sol Issue: Absence of a two-step process for ownership transfer.

contract MagicSpend is Ownable, IPaymaster {

Implement a nomination and acceptance process for ownership transfers to enhance security. Replay Attacks in domainSeparator()

Files: ERC1271.sol Issue: Potential for replay attacks due to static domain separator.

function domainSeparator() public view returns (bytes32) {

Dynamically recalculate the domain separator to mitigate replay attacks.

6. Potential attack surfaces

The project's potential attack surfaces mainly relate to its integration points, centralized control mechanisms and certain implementation procedures. Key areas of focus include:

Integration with external systems: Contracts like CoinbaseSmartWallet.sol integrate with external platforms that could be exploited if a system is compromised. Ensuring secure and resilient integration is critical to preventing cascading failures.

Centralized checkpoints: Using single-owner or limited multi-owner controls in contracts like MultiOwnable.sol creates central checkpoints that attackers could target. If these accounts are compromised, an attacker could gain significant control over contract functionality.

Replay Attacks: Functions like domainSeparator() in ERC1271.sol are vulnerable to replay attacks, where the same transaction could be executed on different chains or in different contexts, leading to unauthorized actions or loss of assets.

Mitigating these attack surfaces involves implementing robust security practices such as decentralized governance, thorough integration point testing, and adopting secure coding standards to avoid common vulnerabilities.

7. Mitigation Recommendations

The following mitigation strategies are recommended to address identified vulnerabilities and strengthen the project's security posture:

Improve governance mechanisms: Implement multi-signature governance models and decentralized governance to distribute control and reduce the risk of single points of failure or malicious control.

Secure external integrations: Ensure integrations with external services like Coinbase are secure by implementing checks and balances to detect and respond to anomalies or breaches.

Improve contract design: Adopt contract design best practices such as modularization to isolate functions and reduce the impact of potential vulnerabilities.

Regular security audits: Conduct regular and comprehensive security audits, including automated scanning and manual code review, to identify and address new vulnerabilities.

8. System risks and architectural deficiencies

The project exhibits systemic risks and architectural weaknesses that could compromise its stability and security:

Dependence on external services: Reliance on external platforms increases the risk of system failures if these services are compromised. Complex contract interactions: Contract interdependence can lead to complex interactions that are difficult to manage and secure, potentially creating hidden vulnerabilities.

Upgradability and flexibility: A lack of clear upgrade paths and flexibility in contract design can hinder the ability to respond to security threats or operational needs over time.

Addressing these issues requires approach to system design, focusing on reducing external dependencies, simplifying contractual interactions, and designing for future adaptability.

Time spent:

16 hours