When conducting Android Penetration Testing, it’s crucial to check for a variety of vulnerabilities to ensure that your application is as secure as possible. Here are the top 10 use cases you should consider:
- Insecure Data Storage: This vulnerability occurs when an app stores sensitive information in an insecure manner. Check if the application stores data like user credentials, personal information, or transaction details insecurely on the device.Insecure Data Storage in Android applications occurs when an app stores sensitive information without proper security measures in place. This could mean storing data in plain text or without adequate encryption, making it easy for an attacker to retrieve and exploit this data.Common Causes
- Storing Data in Shared Preferences: Android’s Shared Preferences is an API that allows you to store private primitive data in key-value pairs. However, it stores data in plain text, which is not safe for sensitive data.
- Insecure SD Card Storage: Some apps store data on the device’s SD card, which is a public directory and can be accessed by any app that has the READ_EXTERNAL_STORAGE permission.
- Insecure Database Storage: Android provides SQLite for storing data in databases. If not implemented properly, this can lead to insecure data storage.
- Storing Data in Log Files: Sometimes, developers log sensitive information for debugging purposes, but forget to remove these logs in the production version of the app.
- Storing Data in Cache Files: Cached data can sometimes be stored insecurely, allowing other apps or users to access it.
How to Mitigate Insecure Data Storage
- Encrypt Sensitive Data: Always encrypt sensitive data before storing it. You can use strong encryption algorithms like AES with a secure key management strategy.
- Use Android Keystore: The Android Keystore system can be used to store cryptographic keys securely at the hardware level.
- Limit Use of External Storage: Avoid storing sensitive data on external storage where other apps can access it. Use internal storage, which is sandboxed per app, for sensitive data.
- Avoid Logging Sensitive Data: Be mindful of what data you log. Make sure no sensitive data is written to the system logs or your own log files.
- Secure Database Implementation: If you’re using SQLite databases, make sure they are used securely. Implement proper access controls and encrypt sensitive data.
- Secure Cache Files: If sensitive data needs to be cached, ensure it’s stored securely. This could mean encrypting the data, or cleaning up cache files when they’re no longer needed.
- Insufficient Authentication/Authorization: As previously mentioned, this involves weak controls or flaws in the process of verifying a user’s identity (Authentication) or verifying what actions a user can perform (Authorization).
Insufficient Authentication or Authorization is a common security vulnerability that often arises in mobile applications, including Android applications. Here’s a brief description of these terms:
- Authentication is the process of verifying the identity of a user, device, or system. It typically involves a username and password, but can also include other methods like biometrics or OTPs (One-Time Passwords).
- Authorization is the process of granting or denying access to specific resources or functions once a user’s identity has been authenticated. It determines what permissions an authenticated user has, like reading, writing, or modifying a file.
When conducting penetration testing, the case of Insufficient Authentication or Authorization can manifest in several ways. Here’s a potential scenario:
Case Study
Let’s imagine an Android application for an online store that lets users view, purchase, and review products. It also allows users to edit their profile information, like email address and shipping address.
During penetration testing, it’s discovered that while the app correctly requires users to log in (authentication) before they can make a purchase or edit their profile, it doesn’t properly check the user’s permissions when making a POST request to the server to modify profile information (insufficient authorization).
This means that if an attacker was able to capture a legitimate user’s session token (perhaps via another vulnerability in the app or by using a tool to intercept network traffic), they could use that token to make POST requests to the server, effectively allowing them to change the email and shipping address on any user’s profile, not just the profile of the user whose session token they captured. This could lead to unauthorized access to sensitive information, and potentially allow for other malicious activities like intercepting shipments.
In this case, the vulnerability lies in the application’s backend server, which fails to properly verify if the session token included in the request has the necessary permissions to carry out the requested action. Fixing this vulnerability would involve implementing proper authorization checks in the server’s code to ensure that the authenticated user has the right permissions to modify the requested resource.
In addition, the app should also implement security measures to protect the user’s session token, like secure transmission (using HTTPS), token invalidation upon logout, and secure storage on the device.
This case study emphasizes the importance of proper implementation of both Authentication and Authorization in maintaining the security of an application.
- Insecure Communication: Test if the application uses proper encryption when transmitting data. Transmissions over HTTP instead of HTTPS, or using weak or incorrect encryption, could lead to data being intercepted and read during transit.
- Insecure Direct Object References (IDOR): This vulnerability arises when an app exposes a reference to an internal implementation object, like a file, directory, or database key. If exploited, an attacker can manipulate these references to gain unauthorized access to data.
- Unintended Data Leakage: This happens when an app inadvertently sends data to other apps on the same device or leaks sensitive information into log files or over the network.
- Poor Code Quality/Implementation: Test for vulnerabilities related to poor coding practices. This includes hardcoded secrets in the code, not handling errors securely, or using outdated cryptographic algorithms.
- Client-Side Injection: Test for vulnerabilities that allow for injection of malicious scripts or queries. This includes SQL Injection, XML Injection, or JavaScript Injection.
- Improper Session Handling: If an application doesn’t handle user sessions properly, an attacker could hijack a user’s session and impersonate them.
- Security Decisions Via Untrusted Inputs: This vulnerability occurs when an app makes security decisions based on untrusted or unvalidated inputs, such as URLs, which could be manipulated to gain unauthorized access.
- Broken Cryptography: This vulnerability arises when an app uses weak or incorrect cryptographic functions. This could lead to sensitive information being read or altered.
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Sensitive Data Exposure: Sensitive Data Exposure is a common vulnerability where an application doesn’t adequately protect sensitive information such as user credentials, credit card information, personal user details, etc. This could occur due to multiple reasons including weak encryption, insecure data storage or transmission, or poor session management.
Android app penetration testing plays a crucial role in avoiding Sensitive Data Exposure:
- Identify Vulnerabilities: Penetration testing can help identify security vulnerabilities in your app, such as insecure communication, insecure data storage, or insufficient encryption, which might lead to Sensitive Data Exposure.
- Validation of Security Measures: If you have implemented certain security measures, penetration testing can validate whether they are functioning as intended and are effective against potential attacks.
- Mitigate Risks: By identifying the potential vulnerabilities, you can take corrective actions to fix them, thereby mitigating the risks of Sensitive Data Exposure.
- Regulatory Compliance: For apps handling sensitive user data, especially in sectors like finance or healthcare, complying with data security regulations is mandatory. Penetration testing can ensure your app meets the necessary security standards, thereby avoiding penalties for non-compliance.
- Protect Reputation: A breach of sensitive data can lead to loss of trust and damage to the reputation of your business. Regular penetration testing helps avoid such scenarios.
- Secure Development Lifecycle: Penetration testing should be part of your Secure Software Development Lifecycle (SSDLC), which means security is considered and tested throughout the development of your app, rather than being an afterthought.
Therefore, regular Android app penetration testing is a must to ensure the secure handling of sensitive data, and avoid potential data breaches, maintaining the trust of your users and upholding your organization’s reputation.
These use cases cover a broad range of potential vulnerabilities. However, every application is unique, and it’s important to tailor your testing to the specific features and functions of the application you’re testing. Also, it’s crucial to keep up-to-date with new threats and vulnerabilities, as the landscape of mobile application security is continuously evolving.
