10 Security Testing Interview Questions and Answers for QA Engineers

1. Can you explain what is security testing and what is the purpose behind it?

Security testing is a process of identifying and rectifying security flaws present in a software application, ensuring the reliability and safety of the system against any cyber attacks, data breaches or vulnerability exploitation. It is focused on evaluating the data integrity, confidentiality, availability, and authenticity of a system, analyzing the security risks, and implementing measures to mitigate these risks.

1. Security testing process includes:

• Threat modeling: identifying potential vulnerabilities and attacks that can happen
• Vulnerability scanning: testing codes and applications for existing vulnerabilities or bugs
• Penetration Testing: performing simulated attacks to assess the system’s security
• Security Audit: reviewing systems and processes to ensure that they comply with industry standards and practices
• Code review: reviewing source code for potential security issues

2. The purpose of security testing is to:

• Identify the security risks associated with the system and infrastructure. This can prevent security breaches or data loss that can result in financial loss, business reputation damage, or legal issues.
• Ensure that the system complies with industry standards and regulations, such as PCI-DSS, HIPAA, or GDPR.
• Ensure that confidential information is protected and secure, reducing the likelihood of loss and unauthorized access. For example, if an application stores user data, it is essential for a security tester to make sure that the user's data cannot be stolen through an unauthorized channel.
• Improve the performance of the system by identifying and rectifying any security flaws. Fixing security issues can significantly enhance system quality and reduce risks.

2. How do you identify potential security vulnerabilities? What are the tools you use?

As a QA engineer with expertise in security testing, my primary responsibility is to identify potential security vulnerabilities by conducting thorough testing across all layers of the application. To accomplish this, I typically employ a combination of manual and automated testing techniques, as well as various tools designed specifically for security testing.

1. First and foremost, I start by analyzing the application architecture to identify any potential vulnerabilities in the design. This helps me to create a comprehensive testing plan that covers all aspects of the application.
2. Next, I use various automated testing tools such as OWASP ZAP, Burp Suite, and Nessus to scan the application for common vulnerabilities such as SQL injections, cross-site scripting, and insecure session management. These tools help to identify vulnerabilities efficiently and provide details on how to resolve them.
3. I also conduct manual penetration testing to identify vulnerabilities that automated tools may miss. This involves attempting to exploit weaknesses in the application through various attack scenarios and validating the results.
4. Furthermore, I conduct threat modeling to understand the potential risks associated with the application and prioritize the most critical vulnerabilities to fix.
5. I work closely with developers to implement security best practices such as input validation, password policies, and encryption to prevent future security breaches.

Through the use of these techniques and tools, I have successfully identified and resolved multiple critical security vulnerabilities in previous projects. For example, in my last job, I uncovered a significant vulnerability in the authentication system that allowed unauthorized users to access sensitive data. After reporting this vulnerability to the development team, we worked together to implement a fix, preventing this issue from being exploited by attackers.

3. Can you explain the different types of security testing?

There are several types of security testing that QA Engineers need to be familiar with to ensure the safety and security of the software being developed. Here are some of them:

1. Penetration Testing: This is the process of testing the system by simulating an attack. The goal is to identify vulnerabilities that could be exploited by attackers to gain unauthorized access to the system. For example, during a penetration test on a banking application, it was discovered that the login page was vulnerable to SQL injection attacks.
2. Vulnerability Scanning: This is an automated process of scanning the system for known vulnerabilities. The goal is to identify vulnerabilities that might not be easily detectable by manual testing. For example, during a vulnerability scan on an e-commerce website, it was discovered that the system was vulnerable to Heartbleed attack.
3. Security Auditing: This is a systematic process of examining the system to identify security vulnerabilities and risks. The goal is to assess the overall security posture of the system and provide recommendations for improvement. For example, during a security audit on a healthcare system, it was discovered that the system was not compliant with HIPAA regulations.
4. Code Review: This is a manual process of reviewing the code to identify security vulnerabilities. The goal is to identify vulnerabilities that might not be easily detectable by automated testing. For example, during a code review on a payment gateway application, it was discovered that the code was vulnerable to buffer overflow attacks.
5. Security Testing Tools: There are several security testing tools available in the market that can be used to automate and streamline the security testing process. For example, during a test on an online messaging system, it was discovered that the system was vulnerable to cross-site scripting attacks using the OWASP ZAP tool.

It is important to note that each of these testing types serves a different purpose and should be used in combination to ensure the security of the system.

4. Have you ever found a critical security bug in a production environment? How did you handle it?

Yes, I have found a critical security bug in a production environment while performing a penetration testing on a client's web application. The bug allowed any user with access to the application to access sensitive information about other users without proper authorization. This was a major issue and needed to be addressed right away.

1. The first step was to document the security bug and report it to the development team in charge of the application.
2. I provided a detailed report of how I had discovered the bug and steps for reproducing it to help the developers in resolving it quickly.
3. We then collaborated to create a patch to address the security issue.
4. After the patch was developed, I tested it myself to verify whether the bug was completely resolved and no other issues were introduced during the patching process.
5. The patch was then deployed to the production environment and I performed further testing to ensure that the issue was completely resolved.
6. I also recommended additional security measures to prevent similar bugs and improve the overall security of the application
7. This experience helped me understand the importance of thorough testing and collaboration between QA and development teams in addressing critical security issues.

As a result of my work, the client's application was much more secure, which increased their customer's confidence and trust in the company's security measures.

5. Can you explain the difference between penetration testing and vulnerability scanning?

Penetration testing vs. Vulnerability scanning:

Penetration testing and vulnerability scanning are two techniques used to identify security threats in a system or software program. Although they are often used interchangeably, they refer to different processes.

Vulnerability scanning is an automated process that involves scanning a system or network to identify common vulnerabilities, which could be exploited by attackers. The scanning process checks for known vulnerabilities in software and operating systems, such as missing patches or weak passwords. Typically, a report is generated that outlines the vulnerabilities detected, and recommendations are made for how to fix them. For example, in our recent vulnerability scan, we identified 10 open ports, 5 missing security patches and 2 outdated plugins in the web application, which could potentially be exploited by local attackers. We recommended updating the software to the latest version and configuring a firewall.

Penetration testing, on the other hand, aims to identify and exploit actual security weaknesses in a system using simulated attacks. It’s a manual process that involves a team of testers who mimic real-world attacks to assess how the system responds to them. The goal is to identify vulnerabilities and demonstrate how they could be exploited and the impact it could have on the system. For example, in our recent penetration testing, we were able to bypass the authentication process and gain administrative access to the system by exploiting an SQL injection vulnerability in the login page.

In summary, vulnerability scanning is a passive process that identifies known vulnerabilities in a system, while penetration testing actively exploits vulnerabilities to assess the risk they pose to a system. While vulnerability scanning is generally automated, penetration testing is usually done manually by a team of testers.

Sources:

• https://www.veracode.com/security/penetration-testing
• https://www.nevis.net/en/newsroom/blog/2019/07/01/penetration-testing-vs-vulnerability-scanning-what-exactly-are-they-and-what-are-the-differences

6. Can you explain how a Man-in-the-middle (MITM) attack works?

A Man-in-the-middle (MITM) attack is a type of cyber attack where an attacker intercepts communication between two parties, such as a client and a server.

During a MITM attack, the attacker will position themselves between the two parties and can view, modify, or even inject new data into the communication.

For example, let's say a client is trying to log into their online bank account. The client's computer sends a request to the bank's server to log in. During a MITM attack, the attacker would intercept this request and pretend to be the bank's server, sending a fake login page to the client.

The client would then enter their login credentials, believing they are logging into their bank account. But the attacker would receive this information and use it to log in to the client's real bank account.

This is a dangerous attack because the attacker can gain access to sensitive information, such as login credentials, credit card numbers, and personal information. It can be prevented by using encryption, such as SSL, to protect communication between two parties.

7. Have you ever created a threat model? How did you approach it?

Yes, I have experience in creating a threat model for one of the applications I was responsible for testing. I approached it by first identifying the assets that needed to be protected and their respective security requirements. Then, I brainstormed potential threats and vulnerabilities that could impact those assets and ranked them according to likelihood and impact.

1. Asset: Customer Personally Identifiable Information (PII)
• Security Requirement: Confidentiality
2. Threats and Vulnerabilities:
• Unsecured communication channels (HTTP, FTP)
• Insider threat (employee access to PII)
• SQL Injection attacks on the database
• Unencrypted storage of PII

Using this approach, I was able to create a comprehensive threat model that outlined potential risks and solutions to mitigate them. As a result, we were able to proactively address security concerns and prevent any security incidents from occurring.

8. Can you explain the difference between authentication and authorization?

Authentication and authorization are two important concepts in security testing. Authentication refers to the process of verifying the identity of a user or a system, while authorization refers to the process of determining what actions a user or a system is allowed to perform. In simpler terms, authentication is about confirming who you are, while authorization is about determining what you can do. A good example of how these concepts work together can be seen in a banking application. When a user logs into their bank account, they need to provide authentication credentials, such as a username and password. Once they are authenticated, the system will then determine what actions they are authorized to perform. For example, they may be authorized to view their account balance, transfer funds between accounts, or pay bills. One way to measure the effectiveness of these security testing concepts is through the use of penetration testing. A penetration test is a simulated cyber attack on a system to identify vulnerabilities and potential weaknesses. By conducting a thorough penetration test, an organization can identify areas where authentication and authorization may be lacking and make the necessary changes to improve their security posture. In conclusion, authentication and authorization are two important concepts in security testing that work together to ensure the security of a system. By understanding the difference between the two and implementing strong measures for both, organizations can better protect their systems from cyber attacks.

9. How do you ensure the security of APIs that your product interfaces with?

Answer:

1. Firstly, I ensure that the APIs themselves follow the best security practices such as using HTTPS, OAuth2 or API keys for authentication, input validation, and output sanitization.
2. I also perform vulnerability scanning using tools like Nessus, Burp Suite or OpenVAS to discover any known vulnerabilities in the APIs or their underlying infrastructure.
3. I manually test for common security misconfigurations like insecure headers, CSRF, and XSS vulnerabilities.
4. I use penetration testing tools like ZAP, Metasploit or custom scripts to assess how the APIs hold up against common attacks such as SQL injection, buffer overflow attacks, and denial of service attacks.
5. I test how the APIs can hold up against brute-force attacks and also assess the impact of any successful denial of service attacks.
6. I use tools like Wireshark to monitor network traffic to ensure that the data being transmitted is encrypted and not vulnerable to any man-in-the-middle attacks.
7. I also test for vulnerabilities in the APIs’ authorizations and access controls to ensure that only authorized users can use the APIs to access sensitive data.
8. Lastly, I evaluate the APIs’ logging and monitoring capabilities to ensure that any security breaches or threats are detected immediately, and appropriate actions are taken immediately to prevent any damages.

As a result of these security testing activities, I have been able to identify and fix several vulnerabilities in APIs in my previous roles as a QA engineer. For instance, I discovered a critical XSS vulnerability in one of the APIs used by a banking client, which could have allowed an attacker to steal customers’ banking details. I immediately notified the concerned parties, and the vulnerability was fixed within hours, thereby preventing any potential financial loss and damage to the bank’s reputation.

10. Can you describe how you would approach testing an application for injection vulnerabilities?

When approaching testing for injection vulnerabilities, my first step would be to identify all user inputs that have the potential to be exploited through injection. This includes inputs such as form fields, URLs, and cookies.

1. Next, I would attempt to input various types of malicious data into these inputs, including SQL injection, cross-site scripting, and command injection. I would use tools such as Burp Suite or OWASP ZAP to automate this process and identify any vulnerabilities.
2. Once vulnerabilities have been identified, I would prioritize and categorize them based on their severity and likelihood of exploitation. I would then work with the development team to patch these vulnerabilities and re-test to ensure they have been properly resolved.
3. In addition to manual testing, I would also implement automated testing for injection vulnerabilities using tools such as SQLMap or XSSer. These tools can help identify vulnerabilities that may have been missed during manual testing.
4. Finally, I would conduct regular penetration testing to ensure that the application remains secure over time. This can involve hiring an external firm to simulate a real-world attack on the application and identify any new vulnerabilities that may have been introduced.

Through this approach, I have been able to identify and remediate several injection vulnerabilities in applications I have tested. For example, while testing a financial web application, I identified an SQL injection vulnerability in the login form. This vulnerability allowed an attacker to bypass authentication and access sensitive user data. After working with the development team to patch the vulnerability, I re-tested and confirmed that the application was now secure.

Conclusion

In conclusion, we have covered 10 essential security testing interview questions for QA Engineers, along with their answers. These questions will help you prepare for your next interview and give you an edge over other candidates. As you move forward with your job search, it's important to write a great cover letter. Check out our guide on how to write a great cover letter to showcase your skills and experience. Another important step in your job search is to prepare an impressive quality assurance testing CV. Learn how to do that with our guide on how to prepare an impressive quality assurance testing resume. Finally, if you're looking for a new job opportunity, don't forget to check out our remote Quality Assurance Testing job board. With the increasing demand for remote work, we have a variety of job openings that could fit your skill set and experience.