10 Application Security Engineer Interview Questions and Answers for Security Engineers

1. What inspired you to specialize in Application Security Engineer?

Since early in my career, I have been interested in protecting software against all sorts of threats. However, my true inspiration for specializing in Application Security Engineering came when I was a part of a team that worked on a government project aimed at preventing cyberattacks on a major corporation’s newly launched mobile application.

1. During the project, I observed firsthand how cybersecurity attacks could affect businesses, and I realized the importance of designing secure systems.
2. My work in the project led to a significant reduction in vulnerabilities, which could have had severe consequences. I was elated to see the positive impact of my work on the security of the client's applications.
3. Furthermore, I have found that application security engineers have the unique opportunity to understand software development, prototyping, and also how to protect the application from cybersecurity threats.

Overall, my passion for creating reliable software and protecting businesses drives my interest in Application Security Engineering. I am committed to staying up-to-date with the latest trends and technologies in this field to ensure the applications I work on have the highest levels of security.

2. What are some common vulnerabilities that you have experienced securing in applications?

As an experienced Application Security Engineer, I have encountered numerous vulnerabilities while securing applications. Here are a few common vulnerabilities and how I addressed them:

1. Cross-site scripting (XSS) vulnerabilities: I identified and mitigated XSS vulnerabilities in a web application by thoroughly examining the response and request headers in the code. I also implemented input validation and sanitization checks to prevent the malicious injection of code into the web app. As a result, the number of XSS vulnerabilities was reduced by 70%.

2. SQL Injection (SQLi) vulnerabilities: I identified and mitigated SQLi vulnerabilities in a financial application by implementing parameterized queries as a best practice to ensure that user inputs followed the correct data types. I also used a web application firewall to identify and block suspicious HTTP traffic to the application. As a result, the number of SQLi vulnerabilities was reduced by 90%.

3. Broken authentication and session management: I implemented secure session management in a healthcare application by setting session timeouts and securing them with strong encryption. I also implemented multi-factor authentication for the admin user accounts. As a result, the number of access-related exploits was reduced by 80%.

These are just a few of the common vulnerabilities that I have tackled in the past. I am confident that my experience and expertise would help your organization enhance the security of its applications.

3. What are some best practices you follow to integrate security into SDLC?

As an Application Security Engineer, integrating security into Software Development Life Cycle (SDLC) is critical. I follow several best practices to ensure the products and platform I work on are secure:

1. Secure design review: I review the application design to ensure security is integrated into the product's architecture.
2. Code review: I regularly review the developer's code as it's being developed. I use automated tools for code scanning and conduct manual code reviews to identify vulnerabilities before the code is released.
3. Threat modeling: I work with the team to identify potential threats and evaluate the risks. This helps us to mitigate risks and identify potential vulnerabilities in our product’s design.
4. Vulnerability assessment: I conduct regular vulnerability assessments and penetration testing during the development and production phase. In my previous role, I assisted in conducting a penetration test on a product that helped to identify a critical vulnerability, which was then fixed in the next patch release.
5. DevSecOps: I work hand in hand with the developers, DevOps and product owners to ensure that security is integrated into the development process. For example, in my previous role, I introduced a tool that enabled developers to run security scans on the environment with minimal interaction, increasing the security of the product and reducing the turnaround time for security checks.

By following these best practices, I have successfully helped secure applications and platforms while significantly reducing vulnerabilities found in the production environment.

4. What is your experience with penetration testing tools such as Burp Suite, OWASP ZAP, etc.?

Experience with Penetration Testing Tools

During my career as an Application Security Engineer, I have gained extensive experience in using penetration testing tools such as Burp Suite, OWASP ZAP, and Nmap. These tools have proven to be effective in identifying vulnerabilities in web applications and APIs, and providing insights on how to remediate them.

One particular project where I utilized Burp Suite was for a financial institution's web app. I conducted a comprehensive penetration testing and was able to identify several critical vulnerabilities, including SQL injection attacks and cross-site scripting (XSS) vulnerabilities. Specifically, with Burp Suite's scanning and crawling capabilities, I was able to identify unvalidated user inputs in several forms presented in the application. By crafting malicious payloads and intercepting traffic, I was able to easily execute SQL injection attacks that would dump the databases. The application team was able to resolve these vulnerabilities and were grateful for the identification of these issues before they could be exploited.

Additionally, I have experience with OWASP ZAP, which has been an instrumental tool for identifying vulnerabilities in APIs. In a previous project for a healthcare company, I utilized ZAP to identify several vulnerabilities in an API that had been newly deployed to production. By analyzing request and response times, ZAP helped me identify slow processing times of requests that could lead to denial-of-service (DoS) attacks. Moreover, through the active scanner feature of ZAP, we were able to identify several SQL Injection issues.

Overall, my experience with these tools, as well as other penetration testing tools, has enabled me to discover critical vulnerabilities that could have otherwise been exploited by attackers. Being able to effectively use the tools and provide valuable insights on remediation steps has been instrumental in my role as an Application Security Engineer.

5. What are some steps you take to ensure security compliance with industry security standards such as PCI DSS, HIPAA, NIST, etc.?

As an Application Security Engineer, ensuring compliance with industry security standards such as PCI DSS, HIPAA, NIST, etc. is a critical part of my job. Here are some of the steps I take:

1. Perform regular risk assessments to identify potential vulnerabilities and ensure that all systems adhere to compliance standards
2. Conduct regular security awareness training sessions for all employees to educate them on the importance of maintaining compliance with industry security standards
3. Document all security policies and procedures to ensure they are up-to-date and meet industry security standards requirements
4. Implement security controls and monitoring tools to detect and prevent potential security breaches
5. Conduct regular audits to ensure compliance with industry security standards and regulatory requirements
6. Maintain strong relationships with third-party vendors to ensure they adhere to industry standards for security and data privacy
7. Stay up-to-date with the latest security threats and vulnerabilities through ongoing training and education
8. Regularly review and test disaster recovery plans to ensure they are effective and meet industry standards requirements
9. Collaborate with other teams to ensure all systems and applications are designed and developed with security in mind
10. Perform regular vulnerability scans and penetration testing to identify potential risks and address them before they can be exploited

By implementing these steps, I have been successful in maintaining compliance with industry security standards such as PCI DSS, HIPAA, NIST, etc. In my previous role, I was instrumental in ensuring that our organization met all of the necessary regulatory requirements and achieved a 100% compliance score during our annual compliance audit.

6. How do you stay up-to-date with application security trends and emerging threats?

As a security engineer, I understand the importance of staying up-to-date with application security trends as the cyber threat landscape continues to evolve rapidly.

1. One of the ways I stay current is by regularly attending industry conferences and seminars. These events provide insight into emerging threats and new security solutions. For example, I attended Black Hat USA in 2019, where I learned about the latest cyber threats and advanced defense techniques.
2. Another way I stay informed is by reading industry publications such as Dark Reading, Threatpost, and The Hacker News. These resources provide up-to-date information on the latest security trends and threat actors around the world.
3. Furthermore, I actively participate in security communities such as OWASP (Open Web Application Security Project) and ISACA (Information Systems Audit and Control Association). I engage with professionals from different parts of the world to share knowledge and stay updated with emerging threats.
4. Lastly, I maintain regular communication with vendor partners to understand and test their latest product offerings. I run simulations on their toolkits and observe the results to determine how effective they could be to prevent application vulnerabilities. I was able to alter a few settings on a popular WAF for a customer and reduce false positives by 90% while still protecting the application from known malicious actors.

Combining these methods allows me to stay up-to-date on the latest trends and emerging threats in application security, which enables me to apply the most effective solutions for protecting our applications.

7. How would you approach assessing the security risks associated with a new application?

As an Application Security Engineer, my approach to assessing the security risks associated with a new application would involve the following steps:

1. Understanding the application: My first step would be to gain a thorough understanding of the application, including its purpose, functionality, and the technologies it utilizes.
2. Identifying potential vulnerabilities: Next, I would conduct a threat modeling exercise to identify potential vulnerabilities associated with the application. This could include analyzing user input, data storage, APIs, and third-party integrations.
3. Assessing the threat level: Once I have identified potential vulnerabilities, I would assess the level of threat associated with each one. This would involve analyzing the potential impact of a successful exploit, as well as the likelihood of an attacker exploiting the vulnerability.
4. Developing a mitigation strategy: Based on my threat assessment, I would develop a mitigation strategy to address potential vulnerabilities. This could include implementing secure coding practices, utilizing security frameworks or libraries, or utilizing encryption techniques.
5. Testing the application: Once the application is developed, I would conduct extensive testing to ensure that the identified vulnerabilities have been effectively mitigated. This could involve utilizing penetration testing, code reviews, or running automated scanners.
6. Maintaining ongoing security: To ensure ongoing security, I would implement a security maintenance program that includes regular security assessments, updating security controls, and monitoring for potential threats.

Through this approach, I ensure that any new application is thoroughly assessed and maintained for security risks. For example, in my previous role as an Application Security Engineer at XYZ Company, I analyzed a new application for a client and identified several vulnerabilities related to data storage. By implementing encryption and secure coding practices, we were able to effectively mitigate these vulnerabilities, which resulted in an overall improved application security posture with zero security incidents reported over two years.

8. What are some effective measures that you have taken to prevent SQL injection attacks?

As an Application Security Engineer, preventing SQL injection attacks is a top priority. One of the most effective measures I have taken to prevent these attacks is by implementing parameterized queries. Parameterized queries enable inputs to be handled as a parameter rather than directly as part of the SQL statement.

This prevents attackers from injecting malicious SQL statements into the application by forcing the query parameters to be treated as data rather than code. The result of this approach is that the database only receives data and not executable code, hence providing protection from SQL injection attacks. To give an example, implementing parameterized queries in an e-commerce website with a high volume of transactions resulted in a significant decrease in SQL injection attacks detected (over 90%) and prevented any data breaches resulting in significant financial risk.

Another effective measure I have taken to prevent SQL injection attacks is by strictly limiting the database user privileges. For instance, while creating the database user for the application, I ensure that the user has limited access privileges to only the required databases, tables and columns. This prevents an attacker from having full access to the database and reducing the potential harm that could be caused to the database.

Furthermore, regular training of developers and IT personnel on security best practices is crucial to prevent SQL injection attacks. I have implemented training programs that ensure all team members are equipped with the latest knowledge on potential threats, prevention measures and techniques to detect and respond to security incidents. Over time, this has led to an environment where security is at the core of every team's action, with a high emphasis on secure coding practices.

1. Implemented parameterized queries
2. Strictly limited database user privileges
3. Implemented training programs on security best practices

9. How would you identify and mitigate cross-site scripting attacks?

As an Application Security Engineer, identifying and mitigating cross-site scripting (XSS) attacks is crucial in ensuring the security of the application. Here are the steps I would take:

1. Identifying potential vulnerabilities: Firstly, I would thoroughly analyze the application's codebase and identify the potential points where an attacker could inject malicious code. I would carefully examine any input fields, such as login forms, search bars, or contact forms.
2. Validation and sanitization: I would then implement a strict validation of user input data, making sure that only allowed characters are accepted, and any suspicious input is flagged or blocked. Additionally, I would sanitize any user input, removing any potentially malicious scripts or HTML code that could be injected.
3. Using a Content Security Policy: I would implement a Content Security Policy (CSP) header to restrict the types of content that the application can load or execute, such as scripts, stylesheets, or iframes. This would prevent any untrusted sources from executing malicious code on the user's browser.
4. Training: Lastly, I would educate the development team and users on the risks of XSS attacks and how to avoid them. This would include best practices for input validation and data sanitization, as well as regular testing and monitoring of the application.

As a result of implementing these strategies, the application would have a much higher level of security against XSS attacks. Additionally, regular testing and monitoring would ensure that any new vulnerabilities are quickly identified and addressed, reducing the risk of successful attacks.

10. What are some techniques that you use to integrate security operations into continuous deployment pipelines?

As an Application Security Engineer, I believe that integrating security operations into continuous deployment pipelines is vital for ensuring that an organization's applications remain secure even after being deployed. One technique that I use is to conduct vulnerability scans during the testing phase of the pipeline. This process helps to identify vulnerabilities early and allows for quick remediation before the application is deployed.

1. Another technique that I have found useful in my experience is to incorporate automated security testing into the deployment pipeline. This approach involves running a security suite of tests on the application for every new code change or release. For example, We recently implemented automated security testing for one of our web applications, which resulted in a 40% reduction in the number of security-related issues being reported post-release.
2. To further enhance the security of the pipeline, I have implemented code analysis tools that run during the build process. This process helps to identify and remediate any coding mistakes that could lead to security vulnerabilities.
3. Finally, I ensure that all stakeholders in the development and deployment pipeline are aware of the importance of security operations. I share our security metrics with the other teams to emphasize the significance of their involvement in ensuring that our applications are secure. For example, since our team started sharing security metrics, we have noticed a 20% increase in the number of stakeholders incorporating security practices in their workflows.

Overall, by using a combination of vulnerability scanning, automated security testing, code analysis, and stakeholder awareness, I have found success in integrating security operations into continuous deployment pipelines. These techniques help to ensure that our applications are secure at every stage of development, and we can confidently deploy our applications to production knowing that security has been a top priority.

Conclusion

Application Security Engineer interviews can be daunting, but with the right preparation, you can ace them. Make sure to familiarize yourself with the common interview questions and answers discussed in this blog. Then, take the next steps to write a great cover letter and prepare an impressive security engineering CV to increase your chances of landing your dream remote job. And if you're currently looking for a new job, be sure to check out our remote Security Engineering job board.