Kapital DAO Guild Service - PlayGround Labs

1. INTRODUCTION

Playground Labs engaged Halborn to conduct a security audit on their browser extension, beginning on 2022-09-26 and ending on 2022-10-22. The security assessment was scoped to the Kapital DAO Guild Service browser extension. To begin the test, the Client’s team provided the source code for Halborn to conduct security testing using tools to scan, detect, validate possible vulnerabilities found in the extension and report the findings at the end of the engagement.

The Kapital DAO Guild Service browser extension is a pass-through for the game the user is playing to connect to the backend API. It allows users to authenticate using their Discord credentials and store their JWT on disk, manage their scholarships, forward blockchain requests to the API.

2. AUDIT SUMMARY

The team at Halborn was provided approximately three weeks for the engagement and assigned a full-time security engineer to audit the security of the application. The security engineer is a blockchain and smart-contract security expert with advanced penetration testing, smart-contract hacking, and deep knowledge of multiple blockchain protocols.

The goals of our security audits are to improve the quality of the systems reviewed and to target sufficient remediation to help protect users.

In summary, Halborn identified some security risks that should be addressed by the Playground Labs team.

In more detail, some care should be taken when verifying the origin of Message Events to the extension's Content Script, as to not allow rogue websites to logout or confirm signatures/transactions of the user.

Moreover, it was discovered that the application's API (dev-api.kapital.gg) return custom errors so it discloses technologies used to the end user.

Lastly, it was discovered that the dependencies are not pinned to exact versions and that the CSP of the extension is not as restrictive as it could. Some discoveries were also made that the extension does not check for synthetically generated events, but as there are no attack vectors available currently it was marked as INFORMATIONAL.

To remediate the identified security issues, it is recommended that Playground Labs implements the following high-level remediation actions:

• Validate each message's origin before processing the message.

• Return custom error from the application's API as to not disclose the technologies on which the application relies.

• Pin dependencies to exact versions.

• Make the Content Security Policy as strict as possible.

3. TEST APPROACH & METHODOLOGY

Halborn performed a combination of manual and automated security testing to balance efficiency, timeliness, practicality, and accuracy regarding the scope of the penetration test. While manual testing is recommended to uncover flaws in logic, process and implementation; automated testing techniques assist enhance coverage of the solution and can quickly identify flaws in it.
The following phases and associated tools were used throughout the term of the audit:

• Storing assets securely

• Exposure of any critical information during user interactions with the blockchain and external libraries

• Any attack that impacts funds, such as draining or manipulating of funds

• Application Logic Flaws

• Areas where insufficient validation allows for hostile input

• Application of cryptography to protect secrets

• Input Handling

• Fuzzing of all input parameters

• Web extension misconfiguration

• Technology stack-specific vulnerabilities and Code Audit

• Known vulnerabilities in 3rd party / OSS dependencies.

4. SCOPE

The security assessment was scoped to the following components:

Kapital Guild Service Extension:

• PlaygroundLabs / kap-scholar-extension

  • Git commit ID: c5c6e52787e580528a6875e58092081ea2e980e7

• Git commit ID: c5c6e52787e580528a6875e58092081ea2e980e7