Our Top 10 Advanced Web Application Penetration Testing Techniques

post thumb
by John Svazic/ on 11 Mar 2024

Our Top 10 Advanced Web Application Penetration Testing Techniques

If a web application attack can happen to giant companies like Casio, it can surely happen to your web apps too. Most organizations underestimate the risk of an attack, but in fact, web applications are among the most potent attack surfaces that a cyber hacker can find.

The thing is, many standard penetration tests, such as vulnerability scans, are not enough to calculate if your app is secure from serious threats. You need advanced web application penetration testing techniques to ensure that you protect yourself from the most advanced and evolving threats.

Why Do You Need Web Application Penetration Testing?

Web application testing doesn’t just protect your business from the greatest threats, it also helps you comply with regulations in your industry. In fact, chances are that if you handle significant personal details of your clients, you have some standard to comply with. Examples include HIPAA in healthcare and PCI DSS in eCommerce.

Moreover, if you have a front-facing web app, you’ll need to protect your reputation too. Any amount of downtime due to a cyber threat can cause you to lose business, and it could be harder to gain prospective clients' trust in the future.

Modern web applications require pen testing

Picking The Right Technique

Before we launch into a discussion of the best web application penetration testing techniques, we should clarify that you do not need every single one of them. Your penetration tester will decide, based on your requirements and the type of tech stack you use, which testing tactics are best suited for your business.

This next section will serve as a primer for what gaps to look at when you’re hiring a pen tester. However, if you’re not a cyber security expert yourself, it would be ill-advised for you to carry out any of the following procedures.

Instead, you should have a set of questions prepared to ask various penetration tester candidates. For instance, you could ask them the following questions for each technique.

  • Which tools do they use to execute that technique?
  • How the test mimics a hack that could happen in real life.
  • A time they used this tactic in the past.

Why Threat Modeling is Indispensable In Picking The Right Technique

Threat modeling involves systematically identifying potential threats to your web application, such as unauthorized data access, data tampering, and service disruption. It requires an understanding of the application’s architecture, the data flow between components, and the potential entry points for attackers. By evaluating these aspects, organizations can anticipate how attackers might exploit vulnerabilities and thereby prioritize testing efforts according to the risk level of different parts of the application.

Guiding Penetration Testing Efforts

The primary value of threat modeling in the context of penetration testing lies in its ability to make your testing efforts more targeted. Instead of a broad, unfocused attempt to uncover vulnerabilities, threat modeling directs your attention to areas of the application that are most likely to be exploited by attackers. This strategic focus not only saves time and resources but also increases the chances of detecting critical vulnerabilities that could lead to severe security breaches. Testers will start with this first before executing the next steps of the pen test.

10 Advanced Techniques For Web Application Penetration Testing

1 Advanced SQL Injection Techniques

SQL Injection exploits vulnerabilities in a web application’s database layer, allowing an attacker to execute arbitrary SQL commands. While SQL injection is often a staple of web application penetration testing, a more advanced technique can be a time-based blind SQL injection, where the response time is used to infer database information or out-of-band techniques that use DNS exfiltration to retrieve information.

If your systems only screen for basic injections, then these tactics can easily surpass your defenses. By leveraging advanced techniques, hackers can stealthily extract sensitive data, manipulate database contents, or even gain administrative access to the web application’s underlying database.

To execute this method, pen testers will pay special attention to form inputs, URL parameters, and cookie values that interact with the database.

2 Blind XSS Exploitation

Blind Cross-Site Scripting (XSS) is used to target vulnerabilities that are not immediately apparent in a web application’s user interface. A theoretical attacker will inject malicious scripts in areas where immediate feedback is not provided to the attacker, such as in stored data that is later viewed by a different user or in an administrative console.

This technique simulates attacks where the payload is not triggered during the attack phase but is executed later on when the stored data is viewed by a legitimate user, often an administrator. It’s particularly dangerous because it allows attackers to bypass some front-end security measures and directly target users with higher privileges.

These payloads are designed to “phone home” when executed, typically through web requests or by including external images or scripts that notify the attacker when accessed.

3 Automated CSRF Exploit Generation

Cross-Site Request Forgery (CSRF) exploits a web application’s trust in an authenticated user’s browser, tricking the user into performing actions they didn’t intend to. Automated CSRF exploit generation aims to streamline the creation of exploits for identified CSRF vulnerabilities, making it easier to test the effectiveness of a web application’s defenses against these attacks.

This technique emulates attacks that coerce a user’s browser into executing unauthorized actions on a web application where they are authenticated, such as changing account details or making transactions without the user’s consent. Automated generation of exploits simulates how attackers could create and distribute malicious requests on a large scale.

4 XML External Entity (XXE) Injection

For this one, penetration testers identify endpoints that accept XML input and test for XXE vulnerabilities by injecting XML documents that define an external entity linked to a file URI or a server-controlled resource.

This technique allows attackers to interfere with an application’s processing of XML data, leading to the disclosure of confidential information, denial of service, server-side request forgery (SSRF), and even execution of remote code.

Essentially, XXE testing simulate scenarios where attackers exploit poorly configured XML parsers to extract data from the server, access internal systems, or execute malicious code. It is especially relevant in applications that accept XML files from untrusted sources or use XML extensively for data transfer.

5 Server-Side Request Forgery (SSRF)

SSRF attacks are executed by inducing a server to make requests to unintended locations, either within the server’s own network or to external third-party systems. This can result in unauthorized access to data, interaction with internal services, and information leakage. SSRF is particularly dangerous in cloud environments where internal services might be accessible without proper authentication. Penetration testers look for functionalities in the application that make HTTP requests based on user input, such as image uploaders, URL fetchers, or webhooks. They then craft input that causes the server to initiate requests to unexpected locations.

This technique replicates attacks that exploit the web application’s ability to fetch data from URLs, tricking the server into accessing unauthorized resources. Attackers leverage this to probe internal networks, bypass IP whitelists, and access services that are only accessible from the server’s perspective.

6 WebSockets Hijacking and Testing

WebSocket hacking involves exploiting vulnerabilities in the WebSocket protocol to intercept or manipulate WebSocket communications between a client and a server. This can lead to information leakage, session hijacking, and malicious message injection. Testing for WebSocket vulnerabilities is crucial for applications that rely on this protocol for real-time communication.

This technique imitates attacks that take advantage of insecure WebSocket implementations to eavesdrop on or tamper with WebSocket communications. This can include scenarios where attackers exploit Cross-Site WebSocket Hijacking (CSWSH) to send malicious WebSocket requests using the credentials of a victim user.

7 Advanced Brute-Force Techniques

Advanced brute-force techniques are designed to bypass traditional defense mechanisms against brute-force attacks, such as rate limiting or account lockout policies. These techniques may involve distributed attacks from multiple IP addresses, username enumeration to identify valid user accounts before attempting password guesses, and the application of machine learning to predict password patterns more effectively.

This approach simulates sophisticated attacks that aim to compromise user accounts by systematically guessing passwords, leveraging knowledge of common password practices, and exploiting any available information about the target (such as common username formats or leaked data from other breaches).

8 Object Deserialization Exploits

Object deserialization exploits target vulnerabilities in the way applications deserialize binary data. Attackers craft malicious serialized objects that lead to arbitrary code execution or denial of service when deserialized by the vulnerable application. This can compromise server security, data integrity, and application availability.

This technique replicates attacks that exploit the deserialization process, where untrusted data is used to recreate objects in memory. Attackers can manipulate this process to execute code, escalate privileges, or perform unauthorized actions within the application. Pen testers must find endpoints or functionalities that accept serialized objects and then craft malicious payloads that exploit known vulnerabilities in serialization libraries or frameworks.

9 Testing GraphQL and API Security

Testing GraphQL and API security involves identifying and exploiting vulnerabilities specific to APIs, such as those built with GraphQL. Vulnerabilities might include excessive data exposure, injection attacks, or inadequate authentication and authorization controls. Proper testing ensures that APIs expose only the data and functionality intended, with appropriate security controls in place.

This mimics real-life attacks targeting the underlying logic of APIs, where attackers exploit flaws to access unauthorized information, perform unauthorized actions, or compromise the integrity of the API. It includes exploiting overly permissive queries in GraphQL that can lead to data leakage or denial of service.

10 Container Escape and Docker Security Testing

This technique focuses on identifying and exploiting vulnerabilities within containerized environments, such as Docker, that could allow an attacker to ‘escape’ a container and gain unauthorized access to the host system or other containers. This includes testing for misconfigurations, vulnerabilities within the container runtime, and insecure deployment practices.

It simulates attacks aiming to break out of the isolated environment of a container to access the broader host system, leveraging container-specific vulnerabilities or misconfigurations. This could lead to compromised host systems, data leakage, or the spread of malicious activity across containers.

Penetration testers assess the security of the containerized environment by checking for known vulnerabilities, misconfigurations (such as running containers with high privileges), and insecure networking practices.

Casio Cyber Attack Case Study

Just to show you how easily a web application attack can happen to even the most advanced businesses, let’s walk you through what happened to Casio in October 2023.

Among Casio’s wide range of educational products, they have a free online math tool called ClassPad. Essentially, the tool helps users with things like graphing and other simple math operations. Given Casio’s insufficient security management, attackers were easily able to amass data from customers in over 150 countries, including names, email addresses, order info, and service usage details.

Naturally, the fact that service usage details got leaked is less of an issue for Casio, but on other applications, where even usage can count as highly confidential information, the risks are extremely high.


The attack itself was actually quite unsophisticated. In fact, the main issue was that Casio failed to enable critical network security settings in the development environment. It goes to show that pen testing is not merely required on a finished product, but also in production environments where security is less stringent. Organizations that skimp on pen testing might find themselves in such a situation if they’re not careful.


First and foremost, this incident might have been prevented with just a bit of internal security training on the part of Casio. However, their lack of diligence reflects a wide-ranging need for penetration testing and incident response plans in the event something goes wrong.

Generally speaking, we recommend that large organizations train their employees in cyber security best practices. For instance, your employees should be able to detect phishing attacks, and if they open an email from an unknown sender, never click any links.

That’s just one step towards creating an effective cybersecurity strategy, but having your whole team on board will point you in the right direction.

Consider EliteSec for your next web application penetration test

By now, you can probably tell that the most critical aspect of penetration testing is rigor. Aside from adhering to regulations in your industry, you have clients to protect. Hiring the wrong provider who does not use advanced tools puts your reputation at risk.

If you want to save time and get your penetration test done the right way, reach out to us at EliteSec for a free 30-minute consultation. It’s the best way for us to understand the intricacies of your web apps and the rest of your system before formulating a solution for your business.

We would be more than happy to discuss this topic further and help you test the security for your organization and applications. Contact us today and we’ll be happy to chat with you!

comments powered by Disqus