Android Penetration Testing: An Important Step to Protect Mobile Security
Android applications are often chosen over desktop applications by users because of their ease of use and accessibility. Additionally, there are a wide variety of applications present for Android devices. If Android applications are not secured, they pose a serious threat to users and their privacy. Unsecured Android applications can result in major financial losses due to the openness of the android ecosystem.
So, what can we do? How can Android applications be secured? Well, the answer lies in penetration testing. Android penetration testing, to be precise. Rigorous testing of Android applications through Android penetration testing is one of the best ways to ensure the security of your application and thus, ensure the security of your users.
What is Android Penetration Testing?
The process of finding security vulnerabilities in an Android application is known as Android Penetration Testing. It is an orderly approach where a penetration tester will attack an Android application using various methods and tools to find weaknesses in the application, and make sure it abides by security policies.
Android Penetration Testing aims to find and fix vulnerabilities in Android applications before they can be exploited by cybercriminals. Security issues usually pertain to data theft, information leaks, etc. There are two types of Android Penetration Testing: static code analysis and dynamic code analysis. Let’s take a look at them.
Static Code Analysis: This method involves investigating the code as a part of the development cycle for the application. The penetration tester attempts to find vulnerabilities during the implementation or design phase itself. White-box tests are conducted to find static code vulnerabilities such as SQL injection flaws, buffer overflow, etc. The issues found are fixed before the app is made available to the masses. In short, it is used to study an already packaged application and find code weaknesses without having direct access to the source code.
Dynamic Code Analysis: This method involves testing the Android application when it is running or in its execution state. Both white-box and black-box testing can be used in dynamic code analysis. The advantages of this method are finding runtime errors like null pointers and buffer overflows, finding reflecting forms of dependency, and inspecting each polymorphic state of the application. To summarise, Dynamic Analysis is used to find ways to manipulate application data while the application is running.
Why Do We Need Android Penetration Testing?
As most modern android applications are used for commercial purposes, healthcare, banking, and more, these applications tend to hold sensitive information. Any security vulnerabilities need to be detected and fixed by penetration testers to mitigate security risks.
ParkMobile is a company that created an app for cashless parking in the US. It is still battling a class action lawsuit from a 2021 mobile app data breach that affected 21 million users. The payment application, Klarna, had an application flaw that caused users to log into random accounts of other customers. This led to the exposure of private and sensitive information, including credit card information.
New vulnerabilities surface every day and Android Penetration Testing is essential to avoid fraud attacks, data leaks, and more. It is necessary for companies that want to go live with new apps without having to worry about being attacked or having to face legal issues. You can also use Android Penetration testing to evaluate the developer team’s work and check the IT team’s response since tests can uncover vulnerabilities and misconfigurations in the back-end services used by the app.
Top OWASP Mobile Risks
The Open Web Application Security Project (OWASP) Foundation gives security insights and recommendations for software security. The OWASP Mobile Top 10 list contains security vulnerabilities in mobile apps and provides the best practices to help remediate and reduce these security problems. It is a crucial list that can help prioritise security vulnerabilities in android applications and build good defences that can withstand static as well as dynamic attacks.
- Platform Misuse: Many applications violate the relevant security guidelines and best practices without meaning to. This is why improper usage of Android platforms is a leading threat. Misuse can extend to any feature of the platform or improper implementation of security controls.
- Lack of Data Storage Security: Attackers can easily exploit stolen devices and extract sensitive information which is why improper data storage is a major vulnerability in mobile security. Applications sometimes need to store data which is why developers need to ensure that this data remains in a secure location that cannot be accessed by other applications or individuals.
- Unsafe Communication: Transmitting data from mobile apps usually involves using the Internet or a telecommunications carrier. These transmissions can be intercepted by attackers through compromised networks.
- Authentication Issues: Occasionally, mobile devices may fail to identify users which allows malicious actors to log in with the help of default credentials. Often, attackers can bypass authentication protocols if they have been implemented poorly, directly interacting with the server.
- Lack of Cryptography: Cryptography ensures that information over a network remains encrypted. Insufficient cryptography will allow hackers to decrypt data back to its original state leading to unauthorised access. This vulnerability is easy to exploit hence it is attacked often.
- Insufficient Authorization: Authorization measures prevent intruders from accessing sensitive data and stop them from escalating privileges to expand their attacks. Insecure Direct Object Reference (IDOR) can enable attackers to access files, accounts, and also databases. If the authorization mechanism is unable to verify users and grant permissions then the app is not secured.
- Poor-Quality Client Code: Improper coding practices can lead to vulnerabilities in code. When team members use different coding techniques and do not provide sufficient documentation, the risk of insecure code increases exponentially. Finding this vulnerability is difficult as hackers need to be knowledgeable about poor coding practices.
- Manipulated Code: Often, app stores may have manipulated versions of mobile applications, like apps with modified binaries, including malicious content and backdoors. These counterfeit applications can be delivered directly to the victims through phishing or publishing them on app stores.
- Reverse Engineering Attacks: Applications can be reverse-engineered and attackers can perform code analysis. This is particularly dangerous as attackers can examine and modify the code to inject malicious functions into them. Reverse engineering enables attackers to understand how applications operate and allows them to recompile them.
- Redundant Functionalities: Attackers can inspect mobile applications through log and configuration files, identify, and exploit redundant functionalities to gain access to the back end. For instance, attackers might anonymously execute privileged actions. Manual code reviews can help reduce this risk.
Android Penetration testing can help mitigate these risks leading to the creation of secure apps that can withstand a wide range of cyberattacks. Android Penetration Testing is an important step in ensuring the safety of your users and their personal data.
What are the Best Practices for Android Development?
Android app developers need to face immense pressure to move faster to meet deadlines which may cause them to push security to the back burner. It is important to focus on security during the development of apps, however, and so here are 4 common areas of security failure that can be easily addressed:
- Validating the Contents of Certificates: Additional security layers can be added to HTTPS connections by using certificates. Certificates enforce additional validations when performing connections and include the certificate authority that signed it along with the list of hostnames that are known or accepted by the application. Applications that validate these components reduce the risk of man-in-the-middle attacks.
- Using SSL through HTTPS: HTTP puts private user information out in the open. This can be avoided by using HTTPS instead. HTTPS encrypts data sent to servers and received from them via industry-standard SSL.
- Using the Latest Cryptography: Using older algorithms can make a mobile application non-compliant with industry regulations and leave organisations susceptible to fines and/or legal problems. Using the latest cryptography algorithms and selecting the ones that are suitable for a specific application scenario can help avoid these problems. Developers also need to avoid insecure modes of operation, incorrectly generated cryptographic keys, and initialisation vectors to ensure that the encrypted information cannot be decrypted.
- Do Not Hardcode the Resources of Mobile Apps: Hardcoded information within the source code of a mobile application is often used by attackers to take advantage of users. For example, hackers can use credentials stored inside app files to get access to a user account. They can also find hardcoded API keys or URLs to obtain private data or even completely take over an app.
Open-Source Tools for Android Penetration Testing
Android Penetration Testing has many challenges that are not generally found in standard web application and infrastructure tests. To overcome these, some great open-source mobile security testing tools are available. Let’s take a look at some of them:
- MobSF: Mobile Security Framework (MobSF) is an indispensable tool for Android Penetration Testing. It is a static as well as a dynamic binary analyser that is capable of enumerating security issues quickly. Some of its features include the ability to identify leads for hardcoded API keys or passwords and performing code analysis.
- Frida: It is an instrumentation framework for all mobile testing. It has been described as a Dynamic instrumentation toolkit for developers, reverse engineers, and security researchers.
- Android Debug Bridge: ADB is not an android penetration testing tool in itself, but the Android Debug Bridge can be used to find issues in a mobile application while it is running and also access a shell on a device that has not been rooted. It is a command line tool that comes with the Android SDK and allows for an emulated or USB-connected Android device to be debugged in real-time.
- QARK: The Quick Android Review Kit allows you to pinpoint security loopholes in the source code of the mobile application as well as the APK files. It is a static code analysis tool that provides information about application-related security risks and gives a concise description of issues.
- APKTool: This is a superb tool for any part of the reverse engineering process for Android Penetration Testing. It enables you to decompile and rebuild applications for source code analysis or even to insert additional files. It is often used together with Frida and other tools that turn some of the output of the APKTool into readable classes.