Prepared by:
HALBORN
Last Updated 01/15/2025
Date of Engagement: September 12th, 2024 - September 25th, 2024
Summary
100% of all REPORTED Findings have been addressed
All findings
3
Critical
0
High
0
Medium
1
Low
1
Informational
1
Table of Contents
1. Introduction
Fuelet engaged Halborn to conduct a security assessment of their Fuelet wallet iOS mobile application, which began on September 12th, 2024 and ended on September 25th, 2024. The security assessment was scoped to the Fuelet wallet iOS mobile application. The client team provided both the source code and the respective IPA file to allow the security engineers to conduct testing using tools for scanning, detecting, and validating possible vulnerabilities, and to report the findings at the end of the engagement.
2. Assessment Summary
The team at Halborn was provided a timeline for the engagement and assigned two full-time security engineers to verify the security of the assets in scope. The security engineers are penetration testing experts with advanced knowledge in web, mobile (Android and iOS), reconnaissance, blockchain and infrastructure penetration testing.
The goals of our security assessments are to improve the quality of the systems we review and to target sufficient remediation to help protect users.
The security assessment of the application revealed that the application lacks essential security controls such as jailbreak detection and anti-debugging mechanisms, making it vulnerable to manipulation, reverse engineering, and code tampering. The absence of an authentication check on application start further exposes the app to unauthorized access, allowing attackers to bypass security protocols easily.
To address these issues, it is imperative to implement robust mechanisms to detect and respond to compromised environments, such as jailbreaks and debugging attempts. Introducing mandatory authentication checks upon app startup will also enhance access control and protect user data from unauthorized access. These measures are crucial to mitigating security risks, protecting user information, and maintaining the overall trust and integrity of the application.
For public release, this report was redacted per Fuelet request to exclude certain critical issues. It should be noted that all removed critical issues were fully addressed and resolved by the Fuelet team prior to the report's publication
Scope
The security assessment was scoped to:
Fuelet wallet iOS IPA
Wallet HTTP and API calls made to the following hosts:
3. Test Approach and Methodology
Halborn performed a combination of manual and automated security testing to balance efficiency, timeliness, practicality, and accuracy regarding the scope of the pentest. While manual testing is recommended to uncover flaws in logic, process and implementation; automated testing techniques assist enhance coverage of the infrastructure and can quickly identify flaws in it.
The following phases and associated tools were used throughout the term of the assessment:
Storing private keys and assets securely
Send/Receive tokens and assets securely to another wallet
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
Brute-force attempts
Input handling
Source code review
Fuzzing of all input parameters
Technology stack-specific vulnerabilities and code assessment
Known vulnerabilities in 3rd party/OSS dependencies
4. RISK METHODOLOGY
- 5 - Almost certain an incident will occur.
- 4 - High probability of an incident occurring.
- 3 - Potential of a security incident in the long term.
- 2 - Low probability of an incident occurring.
- 1 - Very unlikely issue will cause an incident.
- 5 - May cause devastating and unrecoverable impact or loss.
- 4 - May cause a significant level of impact or loss.
- 3 - May cause a partial impact or loss to many.
- 2 - May cause temporary impact or loss.
- 1 - May cause minimal or un-noticeable impact.
- 10 - CRITICAL
- 9 - 8 - HIGH
- 7 - 6 - MEDIUM
- 5 - 4 - LOW
- 3 - 1 - VERY LOW AND INFORMATIONAL
5. SCOPE
6. Assessment Summary & Findings Overview
Critical
0
High
0
Medium
1
Low
1
Informational
1
Impact x Likelihood
HAL-01
HAL-03
HAL-02
| Security analysis | Risk level | Remediation Date |
|---|---|---|
| Missing Jailbreak Detection | Medium | Risk Accepted - 12/06/2024 |
| Lack of Anti-Debugging Mechanisms | Low | Risk Accepted - 12/06/2024 |
| Missing Authentication Check on Application Start | Informational | Acknowledged - 12/06/2024 |
7. Findings & Tech Details
7.1 Missing Jailbreak Detection
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Description
Jailbreaking is the process of removing iOS restrictions imposed by Apple, allowing users (and attackers) to gain root access to the device's file system and system functions. This enables the installation of unauthorized apps, access to restricted areas of the file system, and modifications to system security settings. Without proper jailbreak detection, the application is at risk of being run in a compromised environment, which significantly increases the likelihood of unauthorized access, tampering, data theft, and other malicious activities.
Proof of Concept
Score
Recommendation
File System Checks: Validate the presence of files and directories commonly associated with jailbreaking, such as
/Applications/Cydia.app,/bin/bash,/usr/sbin/sshd, and others.Sandbox Integrity Checks: confirm whether the app can break out of its sandbox, which is usually not allowed on non-jailbroken devices.
Runtime Behavioral Checks: Detect suspicious runtime behavior, such as the presence of known jailbreak-related processes, dynamic libraries (e.g.,
MobileSubstrate), or elevated privileges.Privileged API Detection: Check if the app can access restricted APIs or perform operations that are normally blocked on non-jailbroken devices.
Symbolic Link Checks: Detect symbolic links that are commonly used in jailbroken environments to modify the file system.
Remediation
RISK ACCEPTED: The Fuelet team accepted the risk derived from this issue.
7.2 Lack of Anti-Debugging Mechanisms
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Description
The absence of anti-debugging mechanisms in an application represents a significant security vulnerability. Anti-debugging techniques are employed to detect or prevent the use of debugging tools, such as Frida, GDB, LLDB, or other dynamic analysis tools, by attackers or reverse engineers. When these mechanisms are not implemented, it leaves the application vulnerable to manipulation, unauthorized code analysis, reverse engineering, and the extraction of sensitive data, such as encryption keys, credentials, or intellectual property.
Proof of Concept
Score
Recommendation
Debugger Detection: Check for the presence of a debugger using system APIs or specific instructions that behave differently when run under a debugger.
Code Obfuscation: Rename functions and variables, adding bogus code paths, or using encryption for sensitive parts of the code.
Timing Checks: Validate the time taken by critical sections of code to execute. Debugging usually slows down code execution, and significant timing discrepancies can indicate debugging activity.
Environment Checks: Check for known debugging environments, such as checking for known emulator or debugger process names, unusual device states, or modified system libraries.
Remediation
RISK ACCEPTED: The Fuelet team accepted the risk derived from this issue.
7.3 Missing Authentication Check on Application Start
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Description
When switching between applications, the Fuelet application did not lock the wallet to re-ask for the PIN or fingerprint when accessing it again after the application resumed from background.
Such a security measure would provide security in depth. In the case of a stolen phone with the application remaining opened in the background, the thief having access to the screen could view the list of applications opened, re-access the Fuelet wallet and attempt to steal the funds.
Proof of Concept
Put the application in the background, open another application and switch back to the Fuelet application. No prompt will appear asking for a fingerprint check or PIN verification.
Score
Recommendation
Implement a lockout mechanism when switching to another application.
Ask for a PIN or fingerprint check when accessing it again.
Remediation
ACKNOWLEDGED: The Fuelet team acknowledged the risks associated with this issue.
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.
Table of Contents
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