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Chromium Browser Extension - ZKPass

Prepared by:

Halborn Logo

HALBORN

Last Updated Unknown date

Date of Engagement: August 27th, 2024 - September 10th, 2024

Summary

100% of all REPORTED Findings have been addressed

All findings

9

Critical

0

High

0

Medium

0

Low

0

Informational

9

Table of Contents

1. Introduction

zkPass engaged Halborn to conduct a security assessment on their Transgate extension, beginning on 2024-08-27 and ending on 2024-09-10. The security assessment was scoped to the assets provided to the Halborn team.

2. Assessment Summary

The team at Halborn was provided two weeks for the engagement and assigned a full-time security engineer to verify the security of all the applications. The security engineer is a penetration testing expert with advanced knowledge in web, recon, discovery & infrastructure penetration testing and blockchain protocols.

- Improve the security of the implementation

- Identify potential security issues that could be affecting the implementation

During the security assessment of the extension, several vulnerabilities were identified, posing significant risks to the application’s security posture. However, these vulnerabilities have been mostly remediated through specific actions taken, such as patching, code refactoring, or security best practices from the zkPass team.

Key issues included improper input validation, excessive logging of sensitive data, and the use of outdated cryptographic practices. Input handling functions were found to inadequately sanitize user inputs, which could allow attackers to exploit injection vulnerabilities, leading to data compromise or unauthorized access. Sensitive information, including requests and responses, was logged without redaction, exposing the extension to potential data leaks.

Additionally, the use of outdated dependencies presents a major security concern, as these packages may contain known vulnerabilities that have been publicly disclosed. Furthermore, the application relies on TLS 1.2 for secure communication, which, while still supported, lacks the security enhancements provided by TLS 1.3, such as forward secrecy and reduced handshake latency. The absence of encryption for stored session data and the presence of hardcoded sensitive information further exacerbate the risks.

Addressing these vulnerabilities through package updates, implementation of secure coding practices, and adopting modern security protocols will significantly improve the extension's overall security, reducing the likelihood of exploitation and ensuring better protection of user data.

The browser extension is designed with stringent encryption standards, ensuring that all functions and transmitted data are securely protected. No risks to client data privacy were identified in our assessment, confirming that the extension maintains robust safeguards without compromising client information.


3. RISK METHODOLOGY

Every vulnerability and issue observed by Halborn is ranked based on two sets of Metrics and a Severity Coefficient. This system is inspired by the industry standard Common Vulnerability Scoring System.
The two Metric sets are: Exploitability and Impact. Exploitability captures the ease and technical means by which vulnerabilities can be exploited and Impact describes the consequences of a successful exploit.
The Severity Coefficients is designed to further refine the accuracy of the ranking with two factors: Reversibility and Scope. These capture the impact of the vulnerability on the environment as well as the number of users and smart contracts affected.
The final score is a value between 0-10 rounded up to 1 decimal place and 10 corresponding to the highest security risk. This provides an objective and accurate rating of the severity of security vulnerabilities in smart contracts.
The system is designed to assist in identifying and prioritizing vulnerabilities based on their level of risk to address the most critical issues in a timely manner.

3.1 EXPLOITABILITY

Attack Origin (AO):
Captures whether the attack requires compromising a specific account.
Attack Cost (AC):
Captures the cost of exploiting the vulnerability incurred by the attacker relative to sending a single transaction on the relevant blockchain. Includes but is not limited to financial and computational cost.
Attack Complexity (AX):
Describes the conditions beyond the attacker’s control that must exist in order to exploit the vulnerability. Includes but is not limited to macro situation, available third-party liquidity and regulatory challenges.
Metrics:
EXPLOITABILITY METRIC (mem_e)METRIC VALUENUMERICAL VALUE
Attack Origin (AO)Arbitrary (AO:A)
Specific (AO:S)		1
0.2
Attack Cost (AC)Low (AC:L)
Medium (AC:M)
High (AC:H)		1
0.67
0.33
Attack Complexity (AX)Low (AX:L)
Medium (AX:M)
High (AX:H)		1
0.67
0.33
Exploitability EE is calculated using the following formula:

E=∏meE = \prod m_e

3.2 IMPACT

Confidentiality (C):
Measures the impact to the confidentiality of the information resources managed by the contract due to a successfully exploited vulnerability. Confidentiality refers to limiting access to authorized users only.
Integrity (I):
Measures the impact to integrity of a successfully exploited vulnerability. Integrity refers to the trustworthiness and veracity of data stored and/or processed on-chain. Integrity impact directly affecting Deposit or Yield records is excluded.
Availability (A):
Measures the impact to the availability of the impacted component resulting from a successfully exploited vulnerability. This metric refers to smart contract features and functionality, not state. Availability impact directly affecting Deposit or Yield is excluded.
Deposit (D):
Measures the impact to the deposits made to the contract by either users or owners.
Yield (Y):
Measures the impact to the yield generated by the contract for either users or owners.
Metrics:
IMPACT METRIC (mIm_I)METRIC VALUENUMERICAL VALUE
Confidentiality (C)None (C:N)
Low (C:L)
Medium (C:M)
High (C:H)
Critical (C:C)		0
0.25
0.5
0.75
1
Integrity (I)None (I:N)
Low (I:L)
Medium (I:M)
High (I:H)
Critical (I:C)		0
0.25
0.5
0.75
1
Availability (A)None (A:N)
Low (A:L)
Medium (A:M)
High (A:H)
Critical (A:C)		0
0.25
0.5
0.75
1
Deposit (D)None (D:N)
Low (D:L)
Medium (D:M)
High (D:H)
Critical (D:C)		0
0.25
0.5
0.75
1
Yield (Y)None (Y:N)
Low (Y:L)
Medium (Y:M)
High (Y:H)
Critical (Y:C)		0
0.25
0.5
0.75
1
Impact II is calculated using the following formula:

I=max(mI)+∑mI−max(mI)4I = max(m_I) + \frac{\sum{m_I} - max(m_I)}{4}

3.3 SEVERITY COEFFICIENT

Reversibility (R):
Describes the share of the exploited vulnerability effects that can be reversed. For upgradeable contracts, assume the contract private key is available.
Scope (S):
Captures whether a vulnerability in one vulnerable contract impacts resources in other contracts.
Metrics:
SEVERITY COEFFICIENT (CC)COEFFICIENT VALUENUMERICAL VALUE
Reversibility (rr)None (R:N)
Partial (R:P)
Full (R:F)		1
0.5
0.25
Scope (ss)Changed (S:C)
Unchanged (S:U)		1.25
1
Severity Coefficient CC is obtained by the following product:

C=rsC = rs

The Vulnerability Severity Score SS is obtained by:

S=min(10,EIC∗10)S = min(10, EIC * 10)

The score is rounded up to 1 decimal places.
SeverityScore Value Range
Critical9 - 10
High7 - 8.9
Medium4.5 - 6.9
Low2 - 4.4
Informational0 - 1.9

4. SCOPE

REPOSITORY
(a) Repository: Transgate-extension
(b) Assessed Commit ID: -
(c) Items in scope:
  • Transgate-extension-main/TransGate/asset-manifest.json
  • Transgate-extension-main/TransGate/ba20a8bed0ccb80b0fe4.wasm
  • Transgate-extension-main/TransGate/index.html
↓ Expand ↓
Out-of-Scope: New features/implementations after the remediation commit IDs.

5. Assessment Summary & Findings Overview

Critical

0

High

0

Medium

0

Low

0

Informational

9

Security analysisRisk levelRemediation Date
Improper Input Handling and ParsingInformationalSolved - 10/01/2024
Excessive Logging of Sensitive DataInformationalSolved - 10/01/2024
Potential Weakness in Key ManagementInformationalSolved - 10/01/2024
Lack of Encryption for Stored Session DataInformationalRisk Accepted - 10/01/2024
Lack of Validation in Event ListenersInformationalSolved - 10/01/2024
Lack of Validation When Parsing JSONInformationalRisk Accepted - 10/01/2024
Unvalidated URL ManipulationInformationalSolved - 10/01/2024
Outdated packagesInformationalRisk Accepted - 10/01/2024
Use of TLS1.2InformationalFuture Release - 10/01/2024

6. Findings & Tech Details

6.1 Improper Input Handling and Parsing

//

Informational

Description
Proof of Concept
Score
(0.0)
Recommendation
Remediation Comment

6.2 Excessive Logging of Sensitive Data

//

Informational

Description
Proof of Concept
Score
(0.0)
Recommendation
Remediation Comment

6.3 Potential Weakness in Key Management

//

Informational

Description
Proof of Concept
Score
(0.0)
Recommendation
Remediation Comment

6.4 Lack of Encryption for Stored Session Data

//

Informational

Description
Proof of Concept
Score
(0.0)
Recommendation
Remediation Comment

6.5 Lack of Validation in Event Listeners

//

Informational

Description
Proof of Concept
Score
(0.0)
Recommendation
Remediation Comment

6.6 Lack of Validation When Parsing JSON

//

Informational

Description
Proof of Concept
Score
(0.0)
Recommendation
Remediation Comment

6.7 Unvalidated URL Manipulation

//

Informational

Description
Proof of Concept
Score
(0.0)
Recommendation
Remediation Comment

6.8 Outdated packages

//

Informational

Description
Proof of Concept
Score
(0.0)
Recommendation
Remediation Comment

6.9 Use of TLS1.2

//

Informational

Description
Proof of Concept
Score
(0.0)
Recommendation
Remediation Comment

Halborn strongly recommends conducting a follow-up assessment of the project either within six months or immediately following any material changes to the codebase, whichever comes first. This approach is crucial for maintaining the project’s integrity and addressing potential vulnerabilities introduced by code modifications.

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