The best way to assure that mobile applications are protected is to understand the potential risks of security issues and learn the right techniques to protect phones.

Security can be greatly enhanced by implementing secure coding practices, conducting continuous security testing, performing penetration tests, and focusing on positive user experiences.

There is no need to be an expert to implement the latest technology; the correct mobile application testing service may just be what you need to stay within your budget and make the necessary changes to your business. Plus, keep the below-mentioned practices in mind for better results.

1. Produce Secure Code

Software Engineers are expected to write efficient, scalable, maintainable, and secure code. Writing code without considering security is one of the most common mistakes. In a report by Inc, it is estimated that companies lose 400 billion dollars each year due to cyberattacks carried out by hackers.

Most of these cyber-attacks are carried out due to loopholes in the code, which occur without a process that scans the code for security flaws. Due to this reason, it is imperative that companies and software engineers, in particular, make sure to enforce strict code writing and review practices to scan the code for any security-related vulnerabilities that the developer or engineer has written.

Remember that all coding platforms publish and promote secure coding practices and guidelines. Mobile app testing companies and developers are advised to follow these coding methods. More importantly, they should be included in the code review checklist as part of the overall code review process.

Secure coding involves validating inputs, managing memory carefully, avoiding using C functions insecurely, dodging immutable containers when storing sensitive data, etc. Note that this is just a subset of the extensive lists provided by the platforms.

Also Read – Mobile App Security Testing Checklist

2. Minimize Sensitive Data Storage

For security reasons, developers prefer to store sensitive data locally on a device. It is, however, advised that you avoid storing sensitive data as it may increase the risk of security in the future. If there is no other option than to store the data, it is a good idea to use encrypted data containers and/or key chains. You should also add the auto-delete feature, which deletes data after a specified period of time, to minimize the log.

3. Strong Encryption Of Source Code

Source code is subject to two common types of attacks: one when attackers inject malware into vulnerabilities or bugs in the source code, or the other when attackers exfiltrate the code and repackage the app to be delivered to new unsuspecting users with malware installed.

By encrypting the source code of a web or mobile app, developers can prevent the intellectual property (source code) from being exfiltrated (tried), manipulated, or compromised by the attack and, therefore, unusable by hackers.

Encryption can be accomplished in two ways:

• In symmetric encryption, data is encrypted and decrypted using the same key.
• An asymmetric encryption method or public key uses a different encryption key to encrypt and decrypt data. Decryption keys are known as private keys; encryption keys are known as public keys.

The strength of the encryption depends on many factors, including the algorithm used, the key size, how the key is generated, and how the key exchange is conducted.

The following are common encryption standards:

i. Data Encryption Standard

An algorithm with 56 bits of a symmetric key. Designed in the early 1970s, this standard is considered weak due to its small key size.

ii. Triple DES

This symmetric-key block cipher is also known as TDES, 3DES, or Triple DEA, as it applies four times the DES cipher algorithm to each data block while retaining a 56-bit key length on each block of data.

According to the National Institute of Standards and Technology (NIST), DES and 3DES have been deprecated for new applications and will be phased out by the year 2023 for all applications.

iii. RSA

RSA’s public key encryption system was named after its founders. It uses a public key generated from two secret large prime numbers, along with an auxiliary value, where the secret primes are used to decrypt the public key. Commonly used for digital signature-required apps.

iv. Advanced Encryption Standards

AES is also called Rijndael and is a symmetric-key algorithm and a variant of the block cipher of the same name that the US Government / NIST has adopted as the standard. There are various types of ciphers in the AES family, with varying key sizes and block sizes. It is common for encryption tools to rely on AES encryption as their method of encrypting data.

v. Blowfish & Twofish

Even though Blowfish has only a 64-bit block size, it is popular for database and file encryption in software development. Designed to replace Blowfish, Twofish uses a 128-bit block size and supports larger keys that are more resistant to brute-force attacks.

As algorithms evolve to meet emerging risk landscapes, choosing the right encryption type isn’t only about selecting the most secure option but also the best option for the particular application. A larger key, for example, has a higher level of security – but a greater potential for performance degradation.

Also Read – iOS App Security Testing Checklist

4. Deploy Latest Cryptography Algorithms

An attacker can easily break a seemingly secure mobile app using outdated cryptography algorithms such as SHA-2, RC4, and DES. An organization may also face fines or legal repercussions if using old algorithms in a mobile app. By using the latest cryptography algorithms for Android and iOS mobile apps, developers can avoid this problem.

Use keys with a length of at least 2048 bits (preferably 4096 bits) when signing your binary before publishing it.

When generating random values for cryptographic implementations, use SecureRandom or SecRandomCopyBytes on iOS.

The Android developer can take advantage of the Keystore class, and the iOS developer can use the Keychain services to store highly sensitive data.

To guarantee that a malicious actor cannot decrypt the encrypted information, developers should avoid using insecure modes of operation, improperly generated cryptographic keys, and initialization vectors (IVs).

5. Use 3rd Party Libraries With Caution

Open-source components have become an integral part of almost every application today. When developers embed such components into their apps, they are less likely to perform tests and security research, which impacts the app’s overall security. It is crucial that you use third-party open-source components properly if you want to ensure that your app is well-secured.

6. Test & Verify Security Regularly

Many security testing tools scan code for threats automatically and without delay. This verification method has the advantage of being able to provide results in a short period of time. This system, however, does not provide a complete level of security. Therefore, it is clear that the best verification option is the combination of automatic and manual testing.

By conducting regular mobile app security testing, providers can quickly identify and fix issues, minimize potential risks, and avoid reputational and financial losses due to security breaches.

7. Utilize Proper Testing Labs

It is wise to use cloud-based mobile app testing instead of traditional ones since they allow uploading test locations and even run tests within the apps themselves.

8. Go For Authorized APIs

A hacker can unintentionally gain privileges by using APIs that are not authorized and are not well-coded.  For instance, programmers can reuse authorization information easily when making API calls by caching it locally. Furthermore, it simplifies the API usage for coders. However, it also provides attackers with a way to hijack privileges. Experts recommend a central authorization process to ensure the highest level of security for APIs.

Also Read – Introduction to API Security Testing

9. Secure Backend

It is common for mobile applications to be based on a client-server architecture. In such cases, backend servers must be protected against malicious attacks through security measures.

Most developers assume that APIs can only be accessed by apps that have been programmed to access them. You should, however, ensure all APIs you intend to use are verified based on the type of platform on which you intend to build your mobile application since API authentication and transport mechanisms can vary from platform to platform.

10. High-Level Authentication

An authentication procedure involves using passwords or other identifiers to identify you. Interestingly, weak authentication can lead to some of the biggest security vulnerabilities. You should use multifactor authentication to protect your mobile devices and apps from security issues.

Security experts recommend the following techniques for securing mobile apps:

1. Dual-factor authentication
2. Modern authentication methods like retina or fingerprint scanning.

11. Tamper-Detection Technology

Hackers can modify or tamper your personal data to gain access to your code. Nevertheless, such practices can be combated. An active tamper detection system, for instance, can be deployed to ensure that if the code is modified, it won’t operate at all. These techniques aim to alert developers whenever someone tries to change their code or inject malicious code into it.

12. Principle Of Least Privilege For Code

A “least privilege” principle states that apps should only have the permissions needed to function. A hacker who compromises your app cannot do anything outside of what the app would normally do if they were to compromise it.

The attackers may be able to break an application, but they cannot use that application as a stepping stone to attack other systems. For instance, a typical web application might support HTTP requests, database queries, file uploads, and log messages but not more than that.

13. Deploy Proper Session Handling

A session on a mobile device lasts a much longer period of time than one on a desktop. As a result, the server has to work harder to handle sessions when this happens. However, you can alternatively use device identifiers and tokens to identify a session instead of the device itself.

The token can be revoked at any time, making it more secure in case of a lost or stolen device. It is also possible to remotely wipe data from a lost/stolen device and log off the device remotely.

14. Keep An Eye On Background State

Most mobile platforms allow apps to be suspended, frozen, or kept alive in the background. In either of these cases, apps still retain their memory and sometimes their display buffers, which contain screenshots of the app’s interface from when they went to the background.

A developer should erase or encrypt any sensitive data present in memory while entering the app’s background and wipe the display buffer for sensitive UI design views such as passwords or pins.

Using this technique can help you protect sensitive data when your app is running in the background, in memory, or in the display buffer from attackers accessing it.

Also Read – Myths and Facts of Security Testing

Takeaway

Many businesses are concerned about the security of their mobile apps, as attackers may use the data that resides within mobile to gain access to sensitive information. It is possible that they can exploit information to compromise the enterprise’s network. Therefore, you should definitely embed the above-mentioned tips into your security practices.

The future is mobile! However, data breaches are on a constant rise, be it the infamous ParkMobile incident exposed data of close to 21 million^[1] customers or the T-Mobile SIM swap attacks^[2]. This is why app (and website) developers and enterprises must focus on creating a comprehensive mobile app security checklist.

Skipping security testing can be disastrous for the app developer(s) as well as the consumers of the application. As per our experience, it is essential to engage with an expert ​​security testing company in scenarios where you do not have in-house expertise in planning & execution of security tests.

Since there are different forms of security tests, your team must know which categories of tests are applicable for the project. Well, that’s not all. Some forms of security tests are instrumental in producing faster test results. They also help the security researchers and testers in meeting their security objectives. In this blog, we would be covering the following types of security testing:

• Dynamic Application Security Testing (DAST)
• Static Application Security Testing (SAST)
• Interactive Application Security Testing (IAST)

By the end of this blog, you would also get to know about the differences between DAST, SAST, and IAST – the learnings of which will help you in choosing the best security testing approach for your project.

What is Dynamic Application Security Testing (DAST)?

This is a form of black-box testing that is used for unearthing the security vulnerabilities and flaws in the application. Since the tests are a part of DAST are used for testing the features outside in, hence the form of testing is a part of black box testing.

DAST is also referred to as web application vulnerability scanner. The security vulnerabilities in the application are identified by simulating real-world attacks, thereby helping in strengthening the security aspects of the application. Exposed vulnerabilities and flaws are looked into by penetrating the application from the outside using its interfaces.

Unlike other forms of security tests (i.e. SAST and IAST), tests under DAST are performed under a dynamic environment. It is extremely useful in locating the externally visible security vulnerabilities. DAST is the ideal choice of security testing in case you are planning to cover the top ten security risks from OWASP (Open Web Application Security Project):

• Cross Site Scripting
• SQL Injection and command injection errors
• Insecure Server Configuration, etc.

The major upside of DAST over SAST is that the vulnerabilities are identified when the application is in the running state. Whereas in the case of SAST, every line of code is scanned for vulnerabilities when the application is at rest. However, the ideal security testing strategy must encompass the combination of DAST, SAST, and IAST.

Since DAST is instrumental in locating security flaws when the app is in the running state, it is best at finding server and authentication problems since they would require the user to log into the application. DAST can be a part of the security testing strategy laid out for the QA environment as well as the Production environment.

Netsparker, Acunetix, Detectify, PortSwagger, and MisterScanner are some of the most widely used Dynamic Application Security Testing tools. DAST tests all the HTML and HTTP access points. Hence, the security engineer (or security tester) must have immense knowledge about writing security tests that help locate security flaws on the client as well as the server side.

What is Static Application Security Testing (SAST)?

Unlike DAST that analyzes the application outside in, SAST analyzes the code inside out. Needless to mention that SAST is more suited by developers since the vulnerability analysis is performed at the code level.

Static code analyzers that can be used performing SAST for security testing of modern-web applications. Such tools provide in-depth visibility into the data access & permissions, monitor & remediate high-risk data, and more.

As security is an integral part of the application development & testing, both DAST and SAST can be a part of the DevOps (or CI/CD) pipeline. Such a practice will ensure that security vulnerabilities (both static and dynamic) do not make way into the production environment.

Like DAST, developers need to have expertise in coming up with meaningful tests as a part of the SAST strategy. Depending on your budget and project requirements, you could choose either open-source or premium SAST tools.

Some of the widely used free SAST tools are SonarQube, GitGuardian, NodeJsScan, Sqreen, Synk, and OWASP ZAP. The choice of tools will also depend on the industry domain (i.e. e-commerce, fintech, banking, etc.) of your project.

Partnering with a company like KiwiQA that has provided a range of security testing services to a range of clients can help in making the most of DAST and SAST.

Also Read – Mobile App Security Testing Checklist

What is Interactive Application Security Testing (IAST)?

As seen so far, the ideal security testing strategy must encompass the benefits offered by DAST and SAST. Since SAST unearths the vulnerabilities at the code level, it helps in shipping out a more secure code. However, it would be suicidal if the application is shipped by just running Static Application Security tests.

This is where the benefits offered by DAST comes into the picture since it unearths the application vulnerabilities when it is in the running state. On the look of it, SAST generates better results but your security testing strategy is incomplete without DAST.

Interactive Application Security Testing (IAST) brings the best of both worlds – DAST and SAST. It is the ideal approach for security testing of modern web and mobile applications.

Also Read – Security Testing vs. Penetration Testing

As far as the functioning of the ISAT is concerned, an ISAT agent instruments solutions that eventually helps in real-time analysis from inside the application. Interactive application security tests can also be performed from the IDE. It is easy for beginners to get started with ISAT since there is not much learning curve involved in the process. ISAT agents are super easy to install as well.

Since IAST tools instrument applications by deploying agents and sensors in running applications, they need to have access to the complete source code, data flow, frameworks/libraries/other components used by the code, and HTTP requests & responses. Since all the web (and mobile) applications comprise of the front-end and back-end components, IAST solutions would also need access to the back-end infrastructure to uncover security vulnerabilities in the back-end.

ISAT tools produce more accurate results, uncover security issues at scale by covering more code, and verify a wider range of security rules; something that cannot be achieved independently by DAST and SAST.

Conclusion

Considering the rising number of cyber-attacks, it becomes essential for developers and enterprises to focus on security testing of the application. You can achieve the best out of security testing by building a formidable security testing strategy that tests the application when it is in static as well as running state.

SAST can be super useful in security testing of the application when it is in the static code since it identifies the security vulnerabilities at the source code level. On the other hand,  DAST can be super useful in security testing of the application when it is in the running state.

Though DAST and SAST offer a wide range of advantages, an ideal security testing approach must ensure that that application is well tested from all the respective angles. This is where ISAT can be useful since the ISAT agents help in locating security issues when the application is at rest and when it is in the running (or execution) state.

KiwiQA is an experienced outsourced QA vendor that has offered security testing services to a number of clients, thereby enabling them in reaping the maximum benefits offered by DAST, SAST, and IAST.

As per a survey, close to 98 percent of the apps are not completely secure. This is an alarmingly high number since the private data of the app users could be at stake. Hence, mobile app development companies must make app security testing a part of the DevOps and testing lifecycle.

Companies must move away from the mindset where security testing is pushed to the end of the development lifecycle. All the essential security checks must be performed before the changes are made live on the production server. It is recommended to partner with a mobile application testing company in scenarios where you do not have an inhouse security testing team.

In case you are on the lookout for a detailed checklist to get started with security testing, look no further since we have it all covered in this blog. The learnings of this blog will be helpful in devising a security testing strategy for your mobile app.

State Of Mobile App Security

As per the State Of Mobile report^[1] by Data.ai, close to 4.35 Lakh app downloads are performed every minute. Daily time spent by users has also risen to 4.8 hours in 2021.

Though mobile apps have been widely used across the globe, issues still lie with security aspects of many mobile applications. One out of thirty-six apps are not completely secure for end usage. This is an alarmingly high number and the only resort to bring down this number is by relentlessly focusing on improving the app’s security.

Since app security is of prime importance, many companies opt for mobile app testing services for ensuring that mobile applications are tested in a rigorous manner. As far as mobile apps are concerned, they are primarily categorized as:

• Native Apps – Apps that are built using the SDK offered by the respective mobile OS (i.e. Android or iOS)
• Hybrid Apps – Apps with look & feel of native apps but behave like web apps, thereby taking the advantage offered by both the app types
• Web Apps – Apps that are built using HTML and accessed from the mobile web browsers. These are desktop apps that are tailor-made for the mobile viewport

Also Read – Introduction to API Security Testing

Mobile App Security Issues in Android & iOS

Security issues that you would encounter in Android apps might differ from those witnessed in iOS apps. Well, they are two different operating systems – Android is open-source whereas iOS is closed-source.

Many OEM manufacturers add changes to the Android mainline code at different levels (e.g. kernel, middleware, UI) to have a differentiating factor from the competitors. As an Android app developer, it is recommended to opt for native apps if the app needs access to the device capabilities like camera, GPS, sensors, etc.

Now that we have the platform set, let me walk you through the different security issues in Android and iOS.

Mobile App Security Concerns in iOS

It is a well-known fact that iOS apps go through a much wider scrutiny by the apps team before they are made live on the iOS store. However, it might be incorrect to say that iOS apps are not vulnerable to security attacks.

As per OWASP^[2], here are the top 10 security concerns observed in iOS applications:

• Improper Platform Usage
• Insecure Data Storage
• Insecure Communication
• Insecure Authentication
• Insufficient Cryptography
• Insecure Authorization
• Client Code Quality
• Code Tampering
• Reverse Engineering
• Extraneous Functionality

Mobile App Security Concerns in Android

Contrary to iOS applications, Android apps are more vulnerable to security threats. The app screening process to get listed on PlayStore is not so stringent compared to iOS (or iTunes) store.

Some of the major security concerns observed in Android applications^[3] are:

• Social Engineering
• Data leakage through malicious applications
• Spyware
• MITM (Man-in-the-Middle Attacks)
• Permission issues
• Phishing and malvertising

To identify security issues in the mobile applications, it is important to devise a detailed Vulnerability Assessment plan and Security Testing & Pentesting plan.

Also Read – Android Vs. iOS Mobile App Testing

Detailed Mobile Security Testing Checklist

Here are the major pointers that must make way into the security testing checklist:

1. Perform Security Audit

This is the very first step in identifying security issues in the mobile application. As a QA engineer, you need to know the purpose and depth of the audit. For example, if the application is using third-party APIs, you need to make sure that the data is secure whether it is in transit or at rest.

Since there would be multiple areas of security that need to be looked into, you should prioritize the ones that need immediate attention. Authentication and authorization, access permissions, data storage, and cookies are some of the areas that should be looked into at a high priority.

The audit must include the ways to mitigate different types of security threats, along with covering ways in which such security issues can be looked into at early stages of the development & testing cycle.

2. Threat Modeling and Assessment

As mentioned in OWASP^[4], threat modeling is the process of identifying, communicating, and understanding the threats & mitigations within the context of protecting something of great value. In case of mobile applications, threats could be from third-party interactions (e.g. third-party APIs or interactions with third-party servers) or it could be security threat due to poorly designed app architecture.

At this stage, team members need to wear the hats of attackers & users and exploit the security vulnerabilities from all angles. Usage of automated tools like ADB (Android Debug Bridge), MobSF (Mobile Security Framework), and iMAS (iOS Mobile Application Security) can be used for performing automated security tests on Android & iOS applications.

Threat modeling and assessment is an integral step since it helps in realizing a risk-based analysis of the bug priority and its impact. It is an integral part of the mobile app security testing checklist.

3. Security Exploitation

In the previous step, you identified (or assessed) the potential vulnerabilities. Now is the time to use the appropriate pentesting or security testing tools to exploit different vulnerabilities in the app.

Performing this step is critical since it ensures that the security vulnerabilities do not make it to the app that will go live on the app store. QARK (Quick Android Review Kit) and ZAP (Zed Attack Proxy) are the widely used mobile app security testing tools.

In case your team is not experienced enough to use these tools, it is advised to onboard an experienced mobile testing services company like KiwiQA that has the experience of working with a wide range of clients.

4. Fixing Vulnerabilities

By the end of this step, you would have identified the vulnerabilities and even tried to exploit the same. The security vulnerabilities must be divided in different priority buckets so that you (and the team) can patch the security issues as per the priority.

Now, you should have a well-tested app that has been tested well from a security standpoint.

Also Read – Guide To Mobile Application Security Testing

Conclusion

In this blog, we deep dived into the essential aspects of mobile app security testing. Testing the mobile app from a security perspective is important for ensuring customer stickiness. It avoids scenarios of any potential data leaks where vital confidential (or personal) information is accessible to an untrusted environment.

To make the most out of security testing, many developers and enterprises onboard an experienced mobile app testing services company in order to release a more secure mobile app in the respective store.