Web Application Penetration Testing: Key Insights for Security

Companies developing web applications need to be more vigilant than ever about cyber attackers attempting to break into their public-facing software. It’s why web application penetration testing, which simulates hacking attempts, is becoming increasingly important.

Penetration testing helps businesses and developers spot hidden flaws in their code that might have gone unnoticed. What’s more, it’s a good opportunity for developers to “rehearse” what happens if hackers try to break into their applications.

In this guide, we’ll examine what web application testing involves, why it’s important, and what a typical process looks like for the average tester.

What is Web Application Penetration Testing?

Web application penetration testing is a type of security assessment that mimics techniques used by hackers to break into public-facing apps and software.

Testers are essentially ethical hackers who use tools to sniff out vulnerabilities, exploit misconfigurations and weaknesses, and record how much data can be removed or what damage can be done after hacking.

It’s similar to other types of penetration testing in that it follows a general reconnaissance, scanning, exploitation, and reporting process.

Why is Web Application Penetration Testing Important?

Web application penetration testing is becoming increasingly important in a world where hackers are using more sophisticated tools and attack strategies to harvest data and bring down popular services.

Even the biggest platforms aren’t safe from hackers—Amazon Web Services, for example, deploys a shield service protecting various developers running on its framework.

In one quarter of 2020 alone, AWS recorded a staggering 310,954 unique attack events on its web app clients.

Web application penetration testing helps to ensure your sensitive data is thoroughly safeguarded, with testers offering recommendations on how to fix hidden weaknesses.

It’s also widely regarded as one of the most effective ways to get into the mindset of attackers, with testers adopting ethical tools to mimic hacking techniques.

Without penetration testing, web applications are at risk from threat trends such as generative AI-developed ransomware and phishing.

Web Application Penetration Testing Process

The process behind web application penetration testing can vary depending on the tester, tools used, and clients’ needs. However, the following stages usually apply:

1. Planning and Scoping: Testers work with the end client to assess what they want from a penetration test, and the areas they’d like them to analyze.
2. Reconnaissance: At this stage, testers use tools to scan and sniff out any potential weaknesses they might be able to exploit.
3. Vulnerability Assessment: At stage three, testers take the data gained from step two and map out vulnerabilities to prepare for exploitation.
4. Exploitation: The hacking stage, where testers take their vulnerability maps and use tools to break into systems in a controlled environment.
5. Post-Exploitation: Where testers record the activities they can carry out once they’ve broken into a system, for example, recording keystrokes and stealing data.
6. Reporting: At the reporting stage, testers build complete breakdowns of the attacks carried out, and what they discovered.
7. Remediation and Retesting: Finally, testers advise the client on what to do to reinforce their security posture, and arrange for further testing to make sure measures are carried out.

Top Vulnerabilities Identified in Web Application Penetration Testing

Regardless of the testing process and methodologies a tester follows, it’s always wise to keep up to date with prominent vulnerability trends.

OWASP, the Open Web Application Security Project, is a body dedicated to recording the top ten biggest security risks facing web application developers in any 12-month period.

In the past year up to writing, for example, they’ve warned against the following common vulnerabilities, and the potential impact they could have on businesses and data:

• Broken Access Controls: Vulnerabilities where hackers can gain access to extended user privileges by manipulating URLs and code. This allows attackers to gain administrative control over web applications in some cases.
• Cryptographic Failures: Where sensitive data used by a web application is poorly stored or safeguarded. For example, hackers could gain access to passwords and sell data on the dark web.
• Injection Vulnerabilities: Where user data forms aren’t adequately protected or validated, meaning hackers can insert malicious code to bring down systems and access sensitive data.
• Insecure Design: This is a broad category that typically covers design code weaknesses—meaning there are gaps that hackers can spot and exploit to gain access to internal systems.
• Security Misconfigurations: This increasingly prevalent weakness covers areas such as applications hosting unnecessary features, default accounts and passwords, and inadequate security protections at the server level.
• Vulnerable and Outdated Components: Where web applications continue to use software or code that’s no longer supported by its developers. Such weaknesses could allow hackers into systems via backdoors and therefore wreak havoc.

OWASP’s “Top Ten” is highly regarded in the penetration testing community as the standard rules to follow for web application security hardening.

Many testers use OWASP’s data to, for example, prioritize the tools and techniques they use when assessing client apps.

Web Application Penetration Testing Tools

There are several popular web application penetration testing tools specifically designed to explore and exploit public-facing software and gateways. Some of the best-regarded software includes:

• Skipfish: An open source tool used specifically to scan and find vulnerabilities in web apps and websites.
• JohnTheRipper: A password cracking tool that can help testers break into web applications by force guessing passwords, for example, with brute force and dictionary attacks.
• NMap: A popular network scanning tool that’s used to gather mass intelligence on a target’s various ports and operating details—preparing the tester for vulnerability analysis.

Naturally, there are more tools for penetration testing than those listed here—however, the three programs here frequently find their way into professional toolkits.

In some cases, testers might consider a blend of automation vs. manual testing to ensure all vulnerabilities are accounted for.

Best Practices for Web Application Penetration Testing

Penetration testers typically recommend using the following best practices when testing web applications:

• Build a mutual understanding: The very first stage of web application penetration testing is often the most important. It’s here where pen testers and clients should communicate openly and freely about their expectations and any concerns.
• Follow OWASP’s lead: As mentioned, OWASP’s Top Ten and vulnerability guides are incredibly useful in supporting a well-informed penetration testing strategy. Other penetration testing methodologies, such as the Penetration Testing Execution Standard (PTES), are also recommended.
• Consider compliance: Clients and testers should always look carefully at regional and industry compliance standards they are bound to follow. While it’s always good practice to be as secure as possible, without focusing on compliance, some legal points could be missed.
• Choose a reliable penetration tester: Although it might be tempting to try and use penetration testing tools on your own, choosing a reliable tester means you have access to years of expertise.
• Listen carefully to reporting and remediation: Our web application testers extensively map out and explore opportunities for clients to strengthen their security postures. Apply any recommendations you receive—don’t apply guesswork!
• Prepare a wide range of tools: Good advice for in-house testers and external professionals, it’s wise to avoid relying on one or two specific tools alone. The best pen testers use a range of programs in their toolkits for a comprehensive approach.

Conclusion

Web application penetration testing is highly valuable in an ever-changing threat landscape. One of the best ways to understand the thought process and toolkits involved behind hacking is to step into the attacker’s shoes!

VikingCloud supports a range of web application penetration testing services to ensure your public-facing site or software is robust against even the scariest of unknown threats.

If you’d like to know more about how our team can help protect your application for the better, reach out for a free consultation.

FAQ

How Long Does a Web Application Penetration Test Typically Take?

Depending on the scope of the test involved, it can take up to two weeks for a full web application penetration test to fully complete.

That includes initial consultations and discussions, vulnerability scanning, exploits, and reports and remediation. Pen testers set duration and expectations early on in the process.

Is Penetration Testing Necessary for Internal Applications?

Yes—unfortunately, there are malicious attack risks both inside and outside applications and infrastructures. Internal penetration testing can help you assess weaknesses from within your company and prevent rogue employees from leaking data and damaging code.