Web Application Security Interview Questions and answers

A large number of people who are interested in gaining an understanding of the fundamental ideas of web application security are drawn to the website due to a number of notable aspects, one of which is the direction of seasoned training specialists who have a wealth of traditional job experience. Candidates who have successfully acquired knowledge of the best practices for web application security and who have the ability to assess their skills throughout an interview ought to choose this set of outstanding Web Application Security Interview Questions and Answers, which Bytecode Security, the leading cybersecurity training institute in Delhi, has compiled. In this regard, candidates should select this collection.

Using the significant expertise of its trainers in training a wide spectrum of pupils, including both beginners and seasoned professionals, Bytecode Security has compiled these Web Application Security Interview Questions and Answers in this thorough essay. For this article, Bytecode Security has drawn on the extensive experience of its teachers.

Web Application Security Interview Questions and Answers

The following is a list of the standard questions and answers that are asked during interviews for web application security:

1: What is web application security?

Web application security is a term that describes the procedures that are implemented to safeguard websites and online applications against harmful attacks. The implementation of safety precautions that avoid illicit use, data breaches, and other dangers is a vital part of this process. Input validation, authentication, authorization, secure coding techniques, and vulnerability management are some of the methods that are included in these measures.

2: Define web application security and its core principles.

The process of protecting websites and web applications from severe online attacks that take advantage of vulnerabilities is referred to as web application security management. Among the fundamental principles are:

  • Least Privilege,
  • Defense in Depth,
  • Secure Coding Practices,
  • Input Validation & Output Encoding,
  • Regular Security Testing, etc.

3: Explain the OWASP Top 10 web vulnerabilities.

The OWASP Top 10 is a list that identifies the most significant threats to the security of web applications. It offers insights into vulnerabilities that are commonly encountered and assists developers in prioritizing their security efforts. The following is a concise summary of the top five:

  • Broken Access Control,
  • Cryptographic Failures,
  • Injection,
  • Insecure Design,
  • Security Misconfiguration, etc.

4: Differentiate between SQL Injection and XSS attacks.

SQL Injection: It manipulates the database by injecting malicious SQL code into the user input on the database.

XSS (Cross-Site Scripting): The user input that is shown on a web page is injected with malicious code here.

  1. 5: Describe common authentication mechanisms. (Bonus: How do secure password hashing techniques contribute?)

Common authentication mechanisms include:

  • Username and Password: Credentials are provided by users for verification purposes.
  • Multi-Factor Authentication (MFA): In order to log in, additional criteria, such as a code from a mobile application, are required.
  • Social Login: Users login using usernames and passwords from their existing social media accounts.

Moreover, in order to secure password-hashing techniques, I will keep in mind that passwords are stored using secure password-hashing techniques as one-way hashes, which renders them unreadable even in the event that an attacker manages to break into the database. Strong hashing algorithms and random salts are utilized in these methods to provide an additional layer of protection.

6: Explain DoS and CSRF attacks. (Bonus: How can web applications be protected?)

DoS (Denial-of-Service) aims to overload a web application with traffic, making it unavailable for legitimate users.  On the other hand, CSRF (Cross-Site Request Forgery) exploits a user’s logged-in session to perform unauthorized actions on a trusted website.

In addition, the web applications can be protected using the following methods:

  • DoS: Rate limitation, CAPTCHAs, and screening malicious traffic are all things that need to be implemented.
  • CSRF: For the purpose of validating requests and educating individuals on safe browsing practices, CSRF tokens are being utilized.

7: Elaborate on input validation and output encoding for XSS prevention.

Input Validation: The input from the user should be cleaned up by removing any possibly dangerous code before it is processed.

Output Encoding: Before displaying user input on a web page, it is important to encode any special characters that may be present in order to safeguard them from being read as code.

8: Explain the significance of SSL/TLS for secure communication.

The communication that takes place between a web server and a user’s browser is encrypted by SSL/TLS. In this way, important data such as login credentials and monetary details are protected from being acquired by malicious threat actors.

9: Discuss the importance of secure coding practices and how SDLC promotes them.

A key component of secure coding methods is the creation of code that is less susceptible to flaws. Specifically, the Secure Development Lifecycle (SDLC) encourages them in the following manner:

  • It is necessary to incorporate security needs at every stage of the development process.
  • Reviews of the code discover and address any potential vulnerabilities in the system.
  • The testing of security is carried out at a number of different phases of development.

10: Define vulnerability scanners and their role.

Vulnerability scanners are automated tools that are utilized for the purpose of identifying potential security flaws and vulnerabilities in computer systems, networks, and program applications. In the context of preventative security measures, they play an essential role by:

  • Inventory and Discovery,
  • Vulnerability Detection,
  • Prioritization and Risk Assessment,
  • Reporting and Remediation, etc.

11: What is penetration testing and its benefits for web application security?

In penetration testing, also known as pen testing, an online application is subjected to a simulation of an actual attacker’s attempt to take advantage of vulnerabilities in the program. It assists in identifying security vulnerabilities before they are discovered by attackers. Some advantages include:

  • Identification of vulnerabilities in a proactive manner and their subsequent remedies.
  • Understanding of the security posture of an application that has been improved.
  • faith in the application’s capacity to survive attacks has been increased.

12: Describe secure session management practices.

The implementation of secure session management procedures guarantees that user sessions are shielded from unauthorized access. Some of them are:

  • Secure session IDs,
  • HTTPS,
  • Session timeouts,
  • Secure storage, etc.

13: Discuss security considerations for API deployments (data protection & access control).

Safeguarding application programming interfaces (APIs) from unwanted access and data breaches is what is meant by the term “API security.” Take into account the following:

  • Data protection,
  • Access control,
  • Input validation,
  • Rate limiting, etc.

14: Explain how security is integrated throughout the SDLC.

Throughout the software development life cycle (SDLC), security is integrated by:

  • Threat modeling: During the early stages of the development process, identifying prospective adversaries.
  • Secure coding practices: Implementing guidelines for secure coding while the project is being developed.
  • Security testing: Testing for security should be integrated across the entire development lifecycle.
  • Security reviews: Before deployment, do security evaluations of both the code and the architecture.

15: Define continuous security monitoring and its importance.

There is a process known as continuous security monitoring, which involves continuously monitoring web applications for potential security problems. Because of the following reasons:

  • In real-time, it assists in the detection of strikes and helps to reduce damage.
  • It enables the early identification of vulnerabilities that are just beginning to emerge.
  • Specifically, it offers insights that can be used to improve overall security posture.

16: Describe strategies for staying updated on web security threats.

Here are some strategies:

  • Blogs and publications on security that come from credible sources should be followed.
  • Participate in security-related workshops and conferences.
  • Be sure to sign up for the security advisories that software providers provide.
  • Participate in online communities and forums that are devoted to security.

17: What are Web Application Firewalls (WAFs)?

Security devices known as online application firewalls (WAFs) are responsible for filtering traffic that is directed toward online applications. Using predetermined criteria and signatures, they are able to prevent malicious requests from being processed.

18: Discuss security best practices for cloud-based web applications (data encryption & access control).

The following are examples of ideal security procedures for cloud-based applications:

Data Encryption

  • Encrypt data at rest and in transit,
  • Use industry-standard encryption algorithms,
  • Manage encryption keys securely, etc.

Access Control

  • Implement Identity and Access Management (IAM),
  • Principle of least privilege,
  • Multi-Factor Authentication (MFA),
  • Regular access reviews, etc.

Additional Best Practices:

  • Secure configurations,
  • Regular security assessments,
  • Data Loss Prevention (DLP), etc.

19: Identify emerging web security threats and how to address them.

Emerging web security threats include:

  • API security threats,
  • Supply chain attacks,
  • Zero-day attacks, etc.

Moreover, I can address them via the following best procedures:

API security threats:

  • Implement strong authentication and authorization,
  • Validate all API input,
  • Rate limiting,
  • Monitor API activity, etc.

Supply chain attacks:

  • Use secure software development practices,
  • Maintain software libraries,
  • Vet third-party vendors, etc.

Zero-Day Attacks:

  • Maintain a strong security posture,
  • Patch promptly,
  • Deploy Intrusion Detection/Prevention Systems (IDS/IPS), etc.

20: Outline a structured approach for handling a web security incident.

A structured approach for handling a web security incident includes the following steps:

  • Detection and Containment,
  • Investigation,
  • Eradication,
  • Recovery,
  • Reporting and Learning, etc.

21: (Scenario) You identify a potential XSS vulnerability. Describe your approach.

I will track down a potential XSS Vulnerability through the family protocol:

  • Validate the vulnerability,
  • Report the vulnerability,
  • Suggest remediation,
  • Track remediation, etc.

22: (Scenario) Explain your thought process when conducting a security assessment.

I will follow up with the following best practices while conducting a security assessment:

  • Gather information,
  • Identify vulnerabilities,
  • Prioritize risks,
  • Document findings, etc.

23: Discuss the benefits of utilizing OWASP ESAPI for developers.

OWASP ESAPI, which stands for OWASP Enterprise Security API, is a library that is open-source and free to use. It offers developers security-oriented programming capabilities. Some advantages include:

  • Reduced development time,
  • Improved code security,
  • Consistent security posture, etc.

24: Differentiate between positive and negative input validation techniques.

Positive validation: Ensures that the input is in accordance with a particular predetermined format (for example, only receiving emails in a format that is valid).

Negative validation: Checks for dangerous input patterns and excludes them from consideration (for example, screening out script tags from user input).

25: How do secure password hashing techniques protect user credentials?

Passwords are stored using secure password hashing techniques as one-way hashes, which renders them unreadable even in the event that an attacker manages to break into the database. In this manner:

  • Hashing: The use of a cryptographic hashing method results in the transformation of passwords into a string of characters of a predetermined length.
  • Salting: Prior to the hashing process, a random string, known as salt, is applied to the password. By doing so, attackers are prevented from first computing rainbow tables in order to crack passwords.

26: Explain session hijacking and how session management mitigates it.

An attacker will take the session ID of a user and then utilize it to pretend to be the user in order to obtain illicit access to their account as a result is known as Session Hijacking.

Session management mitigations:

  • Secure session IDs,
  • HTTPS,
  • Session timeouts,
  • Secure storage, and many more.

27: Why are consistent software updates critical?

It is common for software upgrades to include security patches that address vulnerabilities that have been exploited by malicious actors. Help is provided via regular software updates:

  • Reducing the attack surface by patching vulnerabilities that are already known.
  • Enhance the application’s overall security posture by following these steps.
  • Reduce the likelihood of zero-day assaults, although this should not be done completely.

28: Define the “principle of least privilege” in access control.

Under the principle of least privilege, users should only be granted the access permissions that are absolutely necessary for them to carry out the tasks that they are responsible for. If an attacker were to obtain access to a user’s account, this would decrease the possible damage that may occur.

29: How can business logic flaws be exploited?

Errors in the logic of an application are known as business logic defects, and they are vulnerabilities that attackers might exploit to gain unauthorized access or even change data. An example of this would be an attacker taking advantage of a vulnerability in the way the program validates purchase quantities in order to make transactions that are not authorized.

30: Why is validating user input on both the client-side and server-side important?

Through the detection of mistakes at an earlier stage and the prevention of needless server calls, client-side validation offers a more satisfying experience for users.

Server-side validation that occurs on the server is necessary because malevolent users can manipulate the validation that occurs on the client in order to circumvent security measures. Validation performed on the server guarantees the safety of the data, even in the event that client-side validation is circumvented.

31: Describe prototype pollution and its security implications.

The JavaScript vulnerability known as prototype pollution allows an attacker to make changes to the prototype of JavaScript objects that are already built into the language. Consequently, this may result in behavior that was not intended, and it may also make it possible for attackers to circumvent security checks or steal data. Utilizing secure coding techniques and maintaining JavaScript libraries with the most recent versions are both examples of mitigations.


All in all, we want to make sure that applicants who have a positive attitude toward this trajectory ought to carefully assess the Web Application Security Interview Questions and Answers that have been provided above. These questions and answers have been compiled by a large number of aggressive penetration testing professionals who hold a range of roles in prominent companies all over the world.

In addition, people who have an interest in upgrading their pen testing talents or who wish to start over can enroll in a wonderful Web Application Security Course provided by Bytecode Security, which is the most prestigious cybersecurity training college in India.  Please visit our official website or call our 24-hour hotline at +91-9513805401 to speak with one of our professional study counselors in order to organize a demonstration session at our superior facilities in the Saket and Laxmi Nagar regions of the Delhi NCR Region.

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