Cyber Security Technical Interview Questions 2024

Cyber security is a critical field that requires a deep understanding of various technical concepts and the ability to apply them in real-world scenarios. Whether you're an experienced professional or just starting out, preparing for a cyber security interview can be challenging due to the breadth of topics involved. This guide presents  essential technical questions that you might encounter during a cyber security interview. Covering everything from foundational principles to advanced security practices, these questions will help you hone your knowledge and demonstrate your expertise to potential employers.

Technical interviews for cyber security roles often focus on assessing your knowledge of security concepts, tools, and practices. Here are some common technical interview questions you might encounter, along with brief explanations to help you prepare:

1. What is a firewall and how does it work?

Answer: A firewall is a network security device that monitors and controls incoming and outgoing network traffic based on predetermined security rules. It can be hardware-based, software-based, or a combination of both. Firewalls create a barrier between trusted internal networks and untrusted external networks, blocking unauthorized access while allowing legitimate traffic.

2. Explain the difference between symmetric and asymmetric encryption.

Answer:

Symmetric Encryption: Uses the same key for both encryption and decryption. It is faster and more efficient but requires secure key distribution. Examples include AES and DES.

Asymmetric Encryption: Uses a pair of keys – a public key for encryption and a private key for decryption. It is more secure for key distribution but slower compared to symmetric encryption. Examples include RSA and ECC.

3. What is a VPN and how does it enhance security?

Answer: A Virtual Private Network (VPN) creates a secure, encrypted connection over a less secure network, such as the internet. It enhances security by encrypting the data transmitted between the user and the VPN server, thereby protecting it from eavesdropping and interception.

4. Describe a Distributed Denial of Service (DDoS) attack and how to mitigate it.

Answer: A DDoS attack involves overwhelming a target system, server, or network with a flood of traffic from multiple sources, rendering it unavailable to legitimate users. Mitigation strategies include using DDoS protection services, implementing rate limiting, and employing traffic filtering solutions.

5. What is SQL Injection and how can it be prevented?

Answer: SQL Injection is a vulnerability that allows attackers to execute arbitrary SQL code on a database by injecting malicious input into a query. Prevention methods include using parameterized queries or prepared statements, validating and sanitizing user input, and employing least privilege principles for database access.

6. Explain the concept of “least privilege” and its importance.

Answer: The principle of least privilege dictates that users and systems should have the minimum level of access necessary to perform their functions. This minimizes the potential impact of security breaches by reducing the number of entities that have access to sensitive data or critical systems.

7. What is a buffer overflow attack and how can it be prevented?

Answer: A buffer overflow attack occurs when a program writes more data to a buffer than it can hold, potentially overwriting adjacent memory and executing malicious code. Prevention measures include using safe programming practices, implementing bounds checking, and employing security mechanisms like Data Execution Prevention (DEP) and Address Space Layout Randomization (ASLR).

8. Describe how a Man-in-the-Middle (MitM) attack works and how to protect against it.

Answer: A MitM attack occurs when an attacker intercepts and potentially alters communications between two parties without their knowledge. Protection strategies include using end-to-end encryption, implementing strong authentication mechanisms, and employing secure communication protocols like HTTPS.

9. What is an IDS and how does it differ from an IPS?

Answer:

Intrusion Detection System (IDS): Monitors network traffic for suspicious activity and alerts administrators of potential threats. It does not take action to block the threats but provides information for further investigation.

Intrusion Prevention System (IPS): Similar to an IDS but also actively takes action to block or prevent detected threats in real-time.

10. What are the key components of a Security Information and Event Management (SIEM) system?

Answer: Key components of a SIEM system include:

Data Collection: Aggregates log and event data from various sources.

Normalization: Converts data into a common format for analysis.

Correlation: Analyzes and correlates data to identify patterns and potential threats.

Alerting: Generates alerts based on predefined rules or detected anomalies.

Reporting: Provides detailed reports and dashboards for monitoring and analysis.

11. Explain the concept of “Defense in Depth.”

Answer: Defense in Depth is a security strategy that employs multiple layers of defense mechanisms to protect against threats. By implementing overlapping layers of security controls (such as firewalls, intrusion detection systems, encryption, and access controls), organizations can enhance their overall security posture and reduce the likelihood of a successful attack.

12. What is Cross-Site Scripting (XSS) and how can it be mitigated?

Answer: Cross-Site Scripting (XSS) is a vulnerability that allows attackers to inject malicious scripts into web pages viewed by other users. Mitigation strategies include validating and sanitizing user input, using Content Security Policy (CSP) headers, and escaping output to prevent script injection.

13. Describe the purpose of an SSL/TLS certificate and how it works.

Answer: An SSL/TLS certificate is used to secure communications between a web server and a client by encrypting the data transmitted over the network. It works by establishing an encrypted connection using a public key infrastructure (PKI) and ensuring that the server’s identity is verified through the certificate authority (CA).

14. What is a zero-day exploit and how can organizations protect against it?

Answer: A zero-day exploit targets vulnerabilities that are unknown to the software vendor and have no patches available. Protection strategies include maintaining up-to-date security software, using intrusion detection and prevention systems, and implementing security best practices such as regular system updates and user training.

15. How do you handle an incident response process?

Answer: The incident response process typically involves the following steps:

• Preparation: Develop and implement an incident response plan and assemble a response team.
• Identification: Detect and confirm the occurrence of a security incident.
• Containment: Isolate affected systems to prevent further damage.
• Eradication: Remove the root cause of the incident and eliminate threats.
• Recovery: Restore affected systems and services to normal operation.
• Lessons Learned: Analyze the incident, review the response process, and update policies and procedures as needed.

16. What is a honeypot, and how is it used in security?

Answer: A honeypot is a security resource used to attract and analyze malicious activities. It is set up as a decoy system to lure attackers and gather information about their methods and tools. This information helps in understanding threats and improving security measures.

17. Explain how Public Key Infrastructure (PKI) works.

Answer: PKI is a framework for managing digital certificates and public-key encryption. It involves a combination of hardware, software, policies, and procedures to manage public and private keys. PKI uses Certificate Authorities (CAs) to issue and verify certificates, enabling secure communication and authentication.

18. What are the main differences between a vulnerability scan and a penetration test?

Answer:

Vulnerability Scan: Automated process that identifies known vulnerabilities in systems and networks, providing a list of potential security issues.

Penetration Test: Manual or semi-automated process where ethical hackers simulate real-world attacks to exploit vulnerabilities and assess the effectiveness of security defenses.

19. Describe how role-based access control (RBAC) works.

Answer: RBAC is an access control mechanism where permissions are assigned based on user roles rather than individual users. Each role has specific access rights, and users are assigned roles based on their job functions. This simplifies management and enforces the principle of least privilege.

20. What is the difference between hashing and encryption?

Answer:

Hashing: Converts data into a fixed-size string of characters, which is typically a hash value. Hashing is a one-way process and is used for data integrity verification.

Encryption: Converts data into a secure format using algorithms and keys, making it unreadable to unauthorized users. Encryption is a reversible process, allowing data to be decrypted back to its original form.

21. Explain what a Security Operations Center (SOC) does.

Answer: A SOC is a centralized unit that monitors, detects, and responds to security incidents within an organization. It employs various tools and processes to analyze security data, manage incidents, and coordinate response efforts to protect the organization's information assets.

22. What are the differences between an IDS and a firewall?

Answer:

Intrusion Detection System (IDS): Monitors and analyzes network traffic for suspicious activity and generates alerts without taking direct action to block threats.

Firewall: Controls network traffic based on predefined rules, blocking or allowing traffic based on security policies to prevent unauthorized access.

23. How does DNS spoofing work, and how can it be mitigated?

Answer: DNS spoofing (or DNS cache poisoning) involves corrupting the DNS cache with false information, redirecting users to malicious sites. Mitigation strategies include using DNSSEC (DNS Security Extensions), validating DNS responses, and configuring DNS servers to reject suspicious updates.

24. What is the purpose of a security patch, and why is it important to apply them promptly?

Answer: A security patch is an update released by software vendors to fix vulnerabilities and bugs. Applying patches promptly is crucial to protect systems from known security threats and reduce the risk of exploitation by attackers.

25. What is the difference between a vulnerability assessment and a risk assessment?

Answer:

Vulnerability Assessment: Identifies and evaluates security vulnerabilities within a system or network, focusing on technical weaknesses.

Risk Assessment: Evaluates potential threats and their impact on an organization, considering both technical and business aspects to prioritize risks and implement appropriate controls.

26. Explain what a man-in-the-browser (MitB) attack is.

Answer: A MitB attack is a type of malware that intercepts and manipulates communications between a user's browser and a web application. It can alter transactions or steal sensitive information without the user's knowledge. Protection includes using updated anti-malware tools and secure browsing practices.

27. What is a digital certificate, and how is it used in web security?

Answer: A digital certificate is an electronic document used to verify the identity of an individual or organization and to facilitate secure communications. It contains a public key and is issued by a Certificate Authority (CA). Digital certificates are used in SSL/TLS to establish encrypted connections between web servers and clients.

28. Describe the concept of “security by design.”

Answer: Security by design involves integrating security principles and practices into the development process from the outset. This approach ensures that security considerations are part of the system architecture and design, rather than being added as an afterthought.

29. What is the purpose of an access control list (ACL)?

Answer: An ACL is a set of rules that defines permissions and access rights for users or systems to resources such as files, directories, or network devices. It controls who can access what resources and what actions they can perform, helping to enforce security policies.

30. How do you perform a forensic analysis of a compromised system?

Answer: Forensic analysis involves:

• Preserving Evidence: Ensure that the compromised system is preserved and not altered.
• Collecting Data: Gather evidence from system logs, memory dumps, and storage devices.
• Analyzing Evidence: Use forensic tools to examine the collected data for signs of compromise.
• Reporting Findings: Document the analysis, including the timeline of events, evidence, and conclusions.

31. What are some common methods used to bypass security controls?

Answer: Common methods include:

• Social Engineering: Manipulating individuals to disclose confidential information or perform actions that compromise security.
• Phishing: Sending fraudulent messages to trick users into revealing sensitive information.
• Exploiting Vulnerabilities: Taking advantage of known or unknown weaknesses in software or systems.

32. Describe the concept of “zero trust” architecture.

Answer: Zero Trust is a security model that assumes no user or device is trusted by default, regardless of their location. It requires continuous verification and authentication for every access request, enforcing strict access controls and monitoring to minimize the risk of unauthorized access.

33. What is the role of a Certificate Authority (CA) in digital security?

Answer: A CA is a trusted entity that issues digital certificates used to verify the identity of users, devices, or organizations. It plays a crucial role in establishing secure communications and authentication by validating and signing certificates.

34. How does an attacker use cross-site request forgery (CSRF) to exploit a web application?

Answer: In a CSRF attack, an attacker tricks a user into performing unwanted actions on a web application where they are authenticated. This can result in unauthorized changes or data exposure. Protection measures include using anti-CSRF tokens and validating requests.

35. What are the primary functions of a security gateway?

Answer: A security gateway performs functions such as:

• Filtering Traffic: Controls and filters network traffic based on security policies.
• Threat Detection: Monitors for suspicious or malicious activity.
• Content Inspection: Analyzes and inspects data for security threats.

36. Explain the concept of “sandboxing” in cyber security.

Answer: Sandboxing involves isolating an application or process in a controlled environment to prevent it from accessing or affecting the rest of the system. It is used to safely execute and test untrusted code or applications without risking the security of the host system.

37. What are the differences between IPv4 and IPv6 in terms of security features?

Answer:

• IPv4: Limited built-in security features, relying on external protocols for encryption and authentication.
• IPv6: Includes IPsec as a mandatory feature, providing built-in support for encryption and secure communications, along with improved address space and routing capabilities.

38. What is a security baseline, and why is it important?

Answer: A security baseline is a set of minimum security standards and configurations required for systems and devices. It ensures consistent security practices and helps in assessing compliance and detecting deviations from established security policies.

39. How do you ensure secure software development practices?

Answer: Secure software development practices include:

• Code Reviews: Regularly reviewing code for security vulnerabilities.
• Static and Dynamic Analysis: Using tools to identify vulnerabilities in code and during runtime.
• Secure Coding Standards: Following best practices and guidelines to avoid common security issues.

40. What is the purpose of an incident response plan, and what should it include?

Answer: An incident response plan outlines the procedures and responsibilities for responding to security incidents. It should include:

• Identification: How to detect and confirm incidents.
• Containment: Steps to limit the impact of incidents.
• Eradication: Procedures for removing the cause of the incident.
• Recovery: Actions to restore normal operations.
• Lessons Learned: Post-incident analysis and improvements to policies and procedures.

Conclusion:

Successfully navigating a cyber security interview requires more than just technical knowledge; it also demands the ability to think critically, solve problems, and communicate effectively. By reviewing and understanding the  questions outlined in this guide, you'll be better equipped to showcase your skills and stand out in the competitive field of cyber security. Remember, preparation is key—take the time to thoroughly understand each concept and practice articulating your answers. With the right preparation, you'll be well on your way to landing your next cyber security role.