20 Web Application Security Interview Questions and Answers

As the number of web applications continues to grow, so does the need for qualified individuals who can ensure the security of these applications. When applying for a position in web application security, you can expect the interviewer to ask questions about your experience and knowledge in this area. In this article, we review some of the most common questions asked during a web application security interview and provide tips on how to answer them.

Web Application Security Interview Questions and Answers

Here are 20 commonly asked Web Application Security interview questions and answers to prepare you for your interview:

1. What is a web application?

A web application is a software program that is accessed over a network, typically through a web browser, and runs on a web server.

2. Can you explain what the OSI model is and how it helps in data communications?

The OSI model is a seven-layer model that helps to standardize data communications between different devices. It helps to ensure that data is properly formatted and that it is sent to the correct destination.

3. What are some common types of attacks that can be launched against a web application?

Some common types of attacks that can be launched against a web application include:

-SQL injection attacks
-Cross-site scripting attacks
-Denial of service attacks
-Brute force attacks

4. How do you secure your code from SQL injection attacks?

SQL injection attacks happen when malicious code is inserted into an SQL query. This can happen when user input is not properly sanitized before being used in a database query. To prevent this, you need to ensure that all user input is properly escaped and filtered before being used in an SQL query.

5. What does an XSS attack involve?

An XSS attack is a type of injection attack where malicious code is injected into a web page. This code is then executed by the web browser of any unsuspecting user who visits the page. The code can be used to steal sensitive information, redirect the user to a malicious site, or perform any other malicious action.

6. What’s the difference between XSS and CSRF?

Cross-Site Scripting (XSS) attacks are a type of injection, in which malicious scripts are injected into webpages. These scripts can then be executed by unsuspecting users who visit the page, resulting in the theft of sensitive information or the execution of malicious code on the user’s machine. Cross-Site Request Forgery (CSRF) attacks, on the other hand, exploit the trust that a user has for a particular website in order to execute unauthorized actions on their behalf. This can be done by tricking the user into clicking a malicious link that submits a forged request to the website on their behalf.

7. What are some best practices to prevent XSS attacks?

Some best practices to prevent XSS attacks include:

-Sanitizing all user input to prevent malicious code from being injected
-Restricting access to sensitive pages and data
-Using a web application firewall to block suspicious traffic
-Keeping all software and libraries up to date

8. Is it possible for HTTP headers to contain malicious content?

Yes, it is possible for HTTP headers to contain malicious content. This is one of the dangers of HTTP header injection attacks. If an attacker is able to inject malicious content into HTTP headers, they can potentially exploit vulnerabilities in a web application.

9. If someone tries to access a site that doesn’t exist on one of our servers, will they see all our other domains as well or just the error page?

If someone tries to access a site that doesn’t exist on one of our servers, they will only see the error page. They will not be able to see any of our other domains.

10. What are some ways in which session hijacking can occur?

Session hijacking can occur in a number of ways, but typically it happens when an attacker is able to gain access to a user’s session ID. This can happen if the session ID is transmitted over an unsecure network connection, or if it is stored in a location that is accessible to the attacker. Once the attacker has the session ID, they can impersonate the user and gain access to the application.

11. What’s the biggest risk when using cookies to store session information?

The biggest risk when using cookies to store session information is that cookies are often stored on the client side, which means that they are more vulnerable to being tampered with or stolen. If a malicious user were to gain access to a user’s cookies, they could potentially hijack the user’s session and gain access to sensitive information.

12. Which ports need to be kept open to facilitate communication with clients over SSL?

In order to communicate with clients over SSL, you will need to keep port 443 open.

13. In your experience, has anyone ever broken into a website you’ve managed? What happened?

Yes, I have had a website broken into before. It was a very frustrating experience. The hacker was able to gain access to the backend of the site and make some changes to the code. This caused the site to malfunction and it took us a while to figure out what was going on and fix the problem.

14. Why would someone launch a man-in-the-middle attack against a web server?

A man-in-the-middle attack can be used to eavesdrop on communications between a web server and a client. By intercepting and modifying the traffic between the two, an attacker can gain access to sensitive information or inject malicious code. This type of attack is often used to steal login credentials or infect a website with malware.

15. Can you explain what directory traversal is?

Directory traversal is a type of attack where an attacker attempts to access files and directories that are outside of the intended path. This can be done by using “../” in a file path in order to move up one directory, and then access files from there. Directory traversal attacks can be used to gain access to sensitive information, and can also be used to overwrite files.

16. What are the differences between static and dynamic websites?

Static websites are those that deliver the same content to every user who visits the site. Dynamic websites, on the other hand, generate content on the fly based on user input or other factors. This makes dynamic websites more flexible and interactive, but also more vulnerable to security risks.

17. What happens if we don’t use correct encoding formats for processing user input?

If we don’t use the correct encoding formats when processing user input, then we open up our application to a number of security risks. One such risk is known as cross-site scripting (XSS), where malicious code is injected into our application that is then executed by unsuspecting users. This can lead to a number of problems, including the theft of sensitive information, the alteration of application data, and the execution of unwanted code on the user’s machine.

18. Are there any risks involved in allowing users to upload files to our website?

Yes, there are always risks involved in allowing users to upload files to a website. These risks can include, but are not limited to, viruses or malware being uploaded and executed on the server, denial of service attacks, or users uploading sensitive information that should not be publicly accessible.

19. Are there any known security vulnerabilities in WordPress?

Yes, there are known security vulnerabilities in WordPress. These vulnerabilities can allow attackers to take over a WordPress site, or to inject malicious code into a WordPress site. WordPress has released security updates to address these vulnerabilities, and it is important to keep your WordPress site up to date in order to protect it from these and other security threats.

20. Have you ever worked with WAFs before? If so, then have you had any issues?

I have worked with WAFs before and have not had any issues.