Penetration testing

What is penetration testing?

Penetration testing, also known as "pen testing," is a security assessment technique in which ethical hackers simulate cyberattacks on a system to identify vulnerabilities before they can be exploited by malicious actors. It is a critical component of a robust security strategy, helping organizations understand their security posture and mitigate risks.

Summary

Penetration testing involves systematically probing for weaknesses across networks, applications, and systems to determine how attackers might breach security defenses. Mobile app penetration testing has become particularly important as mobile devices and apps increasingly handle sensitive data. The OWASP mobile application security verification standard (MASVS) provides a baseline for secure mobile apps, while the OWASP mobile top 10 highlights the most critical mobile security risks.

Pen testing can be conducted manually by skilled testers or through automated tools, with manual tests offering deeper insights into business logic flaws. Combining manual and automated approaches often yields the most comprehensive results.

Deep dive

Penetration testing is an essential process in identifying vulnerabilities and potential entry points in a system, network, or app. It goes beyond simple vulnerability scanning by actively exploiting weaknesses to assess their impact. Mobile app penetration testing is a critical area of focus, as mobile apps handle sensitive personal and financial data.

Mobile app penetration testing

Mobile app penetration testing specifically targets mobile platforms (iOS and Android) to identify security flaws within mobile apps. Testing is vital because mobile apps differ from web and network environments, requiring a specialized approach to evaluate issues like insecure data storage, improper session handling, and insecure communication. Mobile penetration tests also assess the security of app permissions, cryptographic practices, and how the app interacts with APIs and external servers.

OWASP MASVS

The OWASP mobile application security verification standard (MASVS) serves as a baseline for ensuring the security of mobile apps. MASVS outlines security requirements across different levels of rigor—from basic security controls to advanced protections needed for high-risk environments. Pen testers use this framework to evaluate the robustness of mobile apps against known security threats.

OWASP Mobile Top Ten

The OWASP Mobile Top Ten provides a list of the most critical security risks facing mobile apps like insecure data storage, insufficient cryptography, and improper platform usage. This framework helps pen testers prioritize their efforts by focusing on the most common and severe vulnerabilities. It also guides developers in building more secure apps by addressing these issues during the development process.

Manual vs. automated pen tests

Pen tests can be conducted manually or with automated tools—each offering unique benefits. Automated tools are efficient for scanning large codebases and identifying common vulnerabilities quickly.

On the other hand, manual penetration testing offers deeper insights when it comes to business logic flaws, complex authentication mechanisms, and issues that automated tools may overlook. Manual testing is particularly effective for identifying nuanced, context-specific vulnerabilities, especially those related to improper session management or cryptographic weaknesses.

Steps for pen testing a mobile app

Reconnaissance: This phase involves gathering information about the target app, including its architecture, features, and potential entry points. Testers use tools like APK decompilers and network traffic analyzers.
Vulnerability scanning: In this step, penetration testers use both automated tools and manual techniques to identify vulnerabilities. Tools like ZAP and Burp Suite are commonly employed.
Exploitation: Once vulnerabilities are identified, testers attempt to exploit them to understand the potential impact on the app’s security.
Reporting: The final stage involves compiling detailed reports on the vulnerabilities found, their potential impact, and recommended remediation steps. These reports often provide critical insights into improving mobile app security.

Mobile malware prevention

Preventing mobile malware requires a combination of best practices and security tools. Users should regularly update their operating systems and apps to patch vulnerabilities. Downloading apps only from trusted sources, such as official app stores, reduces the risk of downloading malicious software. Implementing mobile security solutions like antivirus and anti-malware tools adds a layer of defense. Furthermore, educating users on recognizing phishing attacks and suspicious apps is essential for reducing infection rates.

Examples

Vulnerability in Revolut's mobile banking app: In 2022, a vulnerability was found in Revolut's mobile banking app due to insecure data storage. Pen testing revealed that sensitive customer data like account numbers and transaction histories were being stored in plaintext within the app's local storage. This flaw falls under a common mobile security risk known as insecure data storage, which ranks as one of the top 10 mobile security risks identified by OWASP.
WhatsApp encryption bypass: In 2024, a vulnerability was found in WhatsApp that allowed governments and hackers to intercept metadata—like who you're texting, when, and from where—without accessing the full message content. This issue arose from WhatsApp’s handling of unencrypted backup files in the cloud, leaving users' message history vulnerable even though the messages remained encrypted. Pen testers would focus on this type of vulnerability by demonstrating how attackers could exploit poor backup encryption to gather sensitive communication data. WhatsApp has since advised users to adjust their backup settings for better security.
XSS vulnerabilities in WordPress plugin Slider Revolution: In 2023, a significant Cross-Site Scripting (XSS) vulnerability was discovered in the popular Slider Revolution WordPress plugin. Penetration testers identified that attackers could exploit this flaw to inject malicious scripts into web pages, potentially leading to data theft or site redirection. Slider Revolution worked with auditors in May 2023 to address these vulnerabilities resulting in releases in April and May 2024 to mitigate the risks. These vulnerabilities are now listed in the Patchstack vulnerability database, reinforcing the importance of continuous penetration testing to uncover and address such flaws before they can be exploited in the wild.
Microsoft Outlook vulnerabilities: In 2024, researchers identified critical vulnerabilities in Microsoft Outlook, one of the most widely used email platforms. These vulnerabilities allowed attackers to exploit remote code execution flaws by sending malicious emails. Penetration testers would attempt to exploit such weaknesses during their assessments, using simulated attacks to determine the potential damage. These flaws were severe enough to prompt Microsoft to release emergency patches. Pen testers' findings highlighted the need for ongoing security measures and timely patching to prevent attackers from exploiting Outlook’s vulnerabilities in real-world scenarios.

History

Penetration testing has its roots in the 1970s when government organizations, like the U.S. Department of Defense, began to actively assess their security measures by simulating cyberattacks. But the formalization of penetration testing as a security practice started in the 1990s as networks and applications became more widespread.

Mobile app penetration testing emerged in the early 2010s as mobile devices and apps began to proliferate. With the rapid growth of mobile platforms like Android and iOS, pen testing methodologies evolved to account for mobile-specific risks. The OWASP mobile top 10 list was introduced in 2014 as a response to the growing number of mobile security vulnerabilities, followed by the development of OWASP MASVS in 2017, which set a new standard for secure mobile development.

Future

The future of pen testing will see an increased reliance on AI-driven tools to enhance automated testing processes for large-scale apps. But manual testing will remain essential to uncover complex vulnerabilities, especially in business logic and advanced authentication systems.

As mobile apps continue to evolve, so will the security landscape. The increased use of biometrics for mobile authentication and 5G networks may introduce new attack surfaces, requiring continuous updates to pen testing practices. The OWASP MASVS and mobile top 10 will evolve in parallel to reflect these emerging risks, providing essential guidance for securing mobile apps.