Top Penetration testing Interview Questions You Need to Know

Prepare for your Penetration testing interview questions with our comprehensive guide featuring essential questions and detailed answers tailored for both freshers and experienced professionals. This resource covers critical topics including common attack vectors, methodologies, tools, and real-world scenarios, ensuring you’re equipped to demonstrate your skills and knowledge. Whether you’re just starting out or seeking to advance your career, our guide offers valuable insights to help you succeed in securing your next role in cybersecurity.

Penetration Testing, often called pen testing, is a cybersecurity practice that simulates a real-world attack on a system, network, or application to identify vulnerabilities before malicious hackers can exploit them. It involves ethical hackers, also known as penetration testers, attempting to breach security defenses by using various techniques, tools, and methods.

Penetration testing is essential for strengthening security because it helps organizations:

• Identify weaknesses in their infrastructure, software, or policies.
• Test the effectiveness of current security controls.
• Gain insights into potential real-world attack vectors.
• Ensure compliance with security standards and regulations.

There are different types of penetration testing, such as:

1. External Pen Testing – Focuses on external-facing assets like websites and servers.
2. Internal Pen Testing – Simulates an attack from within the organization’s network.
3. Web Application Pen Testing – Targets vulnerabilities in web applications.
4. Wireless Pen Testing – Evaluates the security of wireless networks.

The goal is to find and fix security gaps before they are exploited by malicious actors, ensuring that systems and data remain secure.

Top Penetration Testing Interview Questions

Q1. What is pentesting in your own words?
Ans: Penetration testing, or pentesting, is a simulated cyber attack conducted to identify and exploit vulnerabilities in a system, application, or network. The goal is to assess the security posture by mimicking real-world attacks, thus helping organizations understand their weaknesses and improve their defenses before malicious actors can exploit them.

Q2. What are the different penetration phases?
Ans: The different penetration phases typically include:

• Reconnaissance: Gathering information about the target.
• Scanning: Identifying live hosts, open ports, and services running.
• Enumeration: Extracting detailed information such as user accounts and network shares.
• Exploitation: Attempting to exploit identified vulnerabilities to gain unauthorized access.
• Post-Exploitation: Assessing the value of compromised systems and maintaining access.
• Reporting: Documenting findings and providing recommendations for remediation.

Q3. What is SSL Stripping in penetration testing?
Ans: SSL stripping is an attack that downgrades a secure HTTPS connection to an insecure HTTP connection. This allows attackers to intercept and modify data transmitted between the user and the server, thereby compromising sensitive information such as login credentials and personal data.

Q4. Explain Web Application Scanning with w3af in pen-testing?
Ans: w3af (Web Application Attack and Audit Framework) is an open-source tool used for web application scanning. It helps in identifying vulnerabilities such as SQL injection, cross-site scripting (XSS), and others by performing automated tests and providing a comprehensive report on security issues present in a web application.

Q5. What are Socks4a and Proxy Chains?
Ans:

• Socks4a: A protocol used to route network traffic through a proxy server, which helps in anonymizing and securing connections.
• Proxy Chains: A tool that allows routing traffic through multiple proxy servers in sequence, enhancing anonymity and bypassing network filters.

Q6. What is token Impersonation?
Ans: Token impersonation involves hijacking or forging authentication tokens to gain unauthorized access to a system or application. This is done by stealing a valid session token and using it to impersonate a legitimate user, potentially accessing sensitive information or performing actions on behalf of the user.

Q7. Could you describe XSS?
Ans: Cross-Site Scripting (XSS) is a vulnerability that allows attackers to inject malicious scripts into web pages viewed by other users. These scripts can steal sensitive data, manipulate web content, or perform actions on behalf of the user, leading to compromised security and privacy.

Q8. What is XPath Injection in penetration testing?
Ans: XPath injection is an attack that exploits vulnerabilities in web applications that use XPath queries to retrieve data from XML documents. By injecting malicious XPath code, attackers can manipulate the queries to access or modify unauthorized data, potentially exposing sensitive information.

Q9. How do you handle privilege escalation?
Ans: Handling privilege escalation involves identifying and exploiting weaknesses that allow users to gain higher levels of access than originally intended. This may include:

• Identifying Misconfigurations: Finding improperly set permissions or weak access controls.
• Exploiting Vulnerabilities: Using known exploits or methods to gain elevated privileges.
• Maintaining Access: Ensuring persistent access by creating backdoors or other means.
• Mitigation: Implementing proper security controls, regularly auditing permissions, and applying patches to prevent such escalations.

Pentester Interview Questions You Need to Know

Q10. What is Pass the Hash in penetration testing?
Ans: Pass the Hash is an attack technique where an attacker uses hashed credentials to authenticate themselves to network services without needing to know the actual plaintext password. This is done by capturing and reusing the hash of a password, which can grant unauthorized access to systems.

Q11. What are porting public exploits?
Ans: Porting public exploits involves adapting and modifying publicly available exploit code to work with specific systems or applications. This may include adjusting the exploit to account for different versions, configurations, or environments to successfully exploit a vulnerability.

Q12. What is an SSL/TSL connection?
Ans: SSL (Secure Sockets Layer) and TLS (Transport Layer Security) are cryptographic protocols used to secure communications over networks. They provide encryption, data integrity, and authentication to ensure that data transmitted between clients and servers remains confidential and unaltered.

Q13. What are the different encryption types?
Ans: The different encryption types include:

• Symmetric Encryption: Uses the same key for both encryption and decryption (e.g., AES, DES).
• Asymmetric Encryption: Uses a pair of keys, one for encryption and one for decryption (e.g., RSA, ECC).
• Hash Functions: Produces a fixed-size hash value from variable-size input data (e.g., SHA-256).

Q14. Explain the difference between symmetric and asymmetric encryption?
Ans:

• Symmetric Encryption: Uses a single key for both encryption and decryption. It is fast and efficient but requires secure key distribution and management.
• Asymmetric Encryption: Uses a pair of keys—public and private. One key encrypts the data, and the other decrypts it. It is more secure for key exchange and digital signatures but is slower compared to symmetric encryption.

Q15. What is file enumeration and why is it important?
Ans: File enumeration is the process of identifying and listing files and directories within a system or application. It is important because it helps in discovering sensitive or misconfigured files that could be exploited by attackers, such as configuration files, backups, or exposed data, thereby aiding in the assessment of security risks and vulnerabilities.

Q16. Describe a time when you involved a third party to help with pentesting?
Ans: I once worked on a project where we needed advanced web application testing that went beyond our team’s expertise. We engaged a specialized third-party security firm known for its extensive experience with complex web applications. They provided detailed vulnerability assessments and advanced exploitation techniques that complemented our internal efforts, leading to a comprehensive security evaluation and effective remediation strategies.

Q17. How do you pentest with encrypted emails?
Ans: Pentesting with encrypted emails involves several steps:

• Intercepting Emails: Use tools or techniques to capture encrypted email traffic.
• Decrypting: If possible, obtain the decryption keys or credentials required to decrypt the email.
• Analyzing Content: Once decrypted, analyze the content for sensitive information, misconfigurations, or other security issues.
• Testing for Vulnerabilities: Check for potential vulnerabilities in the email handling systems or encryption implementation.

Q18. What is the biggest challenge you’ve faced with penetration testing?
Ans: One of the biggest challenges I’ve faced was dealing with a complex multi-layered security infrastructure that included advanced threat detection systems and stringent access controls. The challenge was to bypass these security measures without triggering alarms or causing disruptions, which required a combination of sophisticated techniques and thorough planning to achieve a successful penetration test.

Q19. How can WHOIS records be useful during information gathering?
Ans: WHOIS records provide valuable information about domain names, including registration details, contact information, and the hosting provider. During information gathering, this data can help identify the organization responsible for the domain, discover potential points of contact, and gain insights into the infrastructure and technologies used, which can be useful for planning and executing a penetration test.

Q20. Have you used different pentesting methodologies?
Ans: Yes, I have used various pentesting methodologies, including:

• OWASP Testing Guide: Focuses on web application security.
• PTES (Penetration Testing Execution Standard): Provides a comprehensive framework for the entire pentesting process.
• NIST SP 800-115: Offers guidelines for technical aspects of pentesting.
• OSSTMM (Open Source Security Testing Methodology Manual): Emphasizes security testing for operational security.

Q21. What is a SQL injection?
Ans: SQL injection is a vulnerability that occurs when an attacker can insert or manipulate SQL queries executed by a web application. By injecting malicious SQL code into input fields or URL parameters, attackers can bypass authentication, retrieve unauthorized data, or modify the database, leading to potential data breaches and system compromises.

Q22. What is John the Ripper tool and how are penetration testers using it?
Ans: John the Ripper is a widely used password cracking tool that supports various hashing algorithms. Penetration testers use it to crack hashed passwords obtained during a pentest, helping to identify weak or compromised passwords. It uses techniques like brute-force attacks, dictionary attacks, and more to recover plaintext passwords from their hashed versions.

Q23. What makes a system vulnerable?
Ans: A system can be vulnerable due to several factors:

• Misconfigurations: Incorrectly set security settings or permissions.
• Unpatched Software: Outdated software with known vulnerabilities.
• Weak Passwords: Easy-to-guess or compromised passwords.
• Unsecured Data: Sensitive information not properly protected.
• Flawed Code: Programming errors or security flaws in applications.

Q24. What are some systems where you performed pentesting?
Ans: I have performed penetration testing on various systems, including:

• Web Applications: E-commerce platforms, content management systems, and custom web applications.
• Network Infrastructure: Corporate networks, firewalls, and VPNs.
• Mobile Applications: Android and iOS apps.
• Cloud Environments: AWS, Azure, and other cloud services.

Q25. What is Hijacking Execution in pen-testing?
Ans: Hijacking execution involves taking control of or manipulating the execution flow of a program or system. This can include:

• Session Hijacking: Taking over an active user session.
• Code Injection: Injecting and executing malicious code within a process.
• Command Execution: Exploiting vulnerabilities to execute arbitrary commands on a system.

Q26. What is XAMPP?
Ans: XAMPP is a free and open-source cross-platform web server solution stack package. It includes Apache (web server), MySQL (database server), PHP, and Perl. XAMPP is used for developing and testing web applications in a local environment before deploying them to a production server.

Q27. What auditing software have you used?
Ans: I have used various auditing software, including:

• Nessus: For vulnerability scanning and assessment.
• OpenVAS: For open-source vulnerability scanning.
• Burp Suite: For web application security testing.
• Qualys: For comprehensive vulnerability management and policy compliance.

Q28. What types of malware have you found when testing?
Ans: During testing, I have encountered various types of malware, including:

• Viruses: Malicious code that attaches itself to legitimate programs.
• Worms: Self-replicating malware that spreads across networks.
• Trojans: Malware disguised as legitimate software.
• Ransomware: Malware that encrypts files and demands payment for decryption.
• Spyware: Software that secretly collects user data and information.

Q29. What are the common attackers you might experience?
Ans: Common attackers include:

• Hacktivists: Motivated by political or social causes, aiming to disrupt or expose information.
• Cybercriminals: Focused on financial gain, often through activities like fraud, ransomware, or data theft.
• Insiders: Employees or contractors who misuse their access to harm the organization.
• Script Kiddies: Inexperienced individuals using pre-written attack scripts or tools.
• Nation-State Actors: State-sponsored entities conducting sophisticated attacks for geopolitical purposes.

Penetration Testing Interview Questions for Experience

Q30. How does social engineering relate to Pentesting?
Ans: Social engineering in pentesting involves manipulating individuals to gain unauthorized access or information. Pentesters simulate social engineering attacks, such as phishing or pretexting, to assess an organization’s susceptibility to such tactics. This helps identify weaknesses in human factors and improve overall security awareness and training.

Q31. What is threat modeling?
Ans: Threat modeling is a systematic process used to identify, analyze, and prioritize potential threats and vulnerabilities within a system or application. It involves creating a model of the system, identifying threats, assessing their impact, and developing mitigation strategies. This process helps in designing secure systems by understanding and addressing potential security risks early in the development lifecycle.

Q32. What are some of the common abbreviations?
Ans: Common abbreviations in pentesting and cybersecurity include:

• XSS: Cross-Site Scripting
• SQLi: SQL Injection
• CSRF: Cross-Site Request Forgery
• DDoS: Distributed Denial of Service
• OSINT: Open-Source Intelligence
• CVE: Common Vulnerabilities and Exposures
• IDS: Intrusion Detection System
• IPS: Intrusion Prevention System

Q33. What is reflected XSS Vulnerability?
Ans: Reflected Cross-Site Scripting (XSS) is a vulnerability where an attacker injects malicious script into a URL or input field, which is then reflected and executed by the web server in the user’s browser. Unlike stored XSS, the payload is not stored on the server but is reflected immediately, allowing attackers to steal cookies, session tokens, or perform other malicious actions.

Q34. What are the key steps in planning a Penetration Testing engagement?
Ans: Key steps include:

• Scope Definition: Clearly define the scope of the test, including systems, applications, and constraints.
• Objectives Setting: Determine the goals of the engagement, such as identifying vulnerabilities or testing response mechanisms.
• Resource Allocation: Assign roles and responsibilities to the pentesting team and gather necessary tools.
• Risk Assessment: Evaluate potential risks associated with the test and establish protocols for handling any impact.
• Schedule Planning: Set timelines for different phases of the engagement and coordinate with stakeholders.
• Report Preparation: Develop a plan for documenting findings and recommendations post-testing.

Q35. What is DNS Reconnaissance in penetration testing?
Ans: DNS Reconnaissance involves gathering information about a target’s domain name system (DNS) to identify potential attack vectors. This can include:

• DNS Enumeration: Discovering subdomains and associated IP addresses.
• Zone Transfers: Obtaining the entire DNS database for the domain, if misconfigured.
• Reverse DNS Lookups: Mapping IP addresses back to domain names.

Q36. How do you explain highly technical terms and threats to leadership?
Ans: To explain technical terms and threats to leadership:

• Use Analogies: Relate technical concepts to everyday situations or business risks.
• Simplify Language: Avoid jargon and use plain language to describe threats and impacts.
• Focus on Impact: Highlight how the threat affects business operations, security posture, and financials.
• Visual Aids: Use charts, graphs, and diagrams to illustrate concepts and findings.

Q37. What is SSHExec?
Ans: SSHExec is a tool or technique used to execute commands on remote systems over SSH (Secure Shell). It allows for remote command execution, file transfers, and system management. In pentesting, SSHExec might be used to gain remote access to a system or to perform administrative tasks as part of an assessment.

Q38. What is Open-Source Intelligence (OSINT) gathering?
Ans: Open-Source Intelligence (OSINT) gathering involves collecting information from publicly available sources, such as websites, social media, and public records, to aid in security assessments. OSINT helps identify potential vulnerabilities, understand the target environment, and gather information for crafting more effective attack simulations.

Q39. Could you explain CSRF?
Ans: Cross-Site Request Forgery (CSRF) is an attack that tricks a user into performing actions on a web application where they are authenticated. By exploiting the user’s authentication context, an attacker can make unauthorized requests, potentially leading to actions such as data modification or account takeover without the user’s consent.

Q40. Have you worked on the different pentest teams?
Ans: Yes, I have worked on various pentest teams, including:

• Web Application Security Teams: Focused on identifying vulnerabilities in web applications.
• Network Security Teams: Specialized in assessing network infrastructure and configurations.
• Mobile Application Security Teams: Tested mobile apps for security flaws and vulnerabilities.
• Cloud Security Teams: Evaluated cloud environments and services for security risks.

Q41. What different approaches do you use for wireless and wired connections?
Ans:

• Wireless Connections: Use tools to scan for available networks, identify weak encryption (e.g., WEP, WPA), and perform attacks such as sniffing and deauthentication. Techniques include using Wi-Fi analyzers and cracking WPA/WPA2 passwords.
• Wired Connections: Focus on network mapping, port scanning, and vulnerability assessments. Techniques involve analyzing network traffic, exploiting misconfigurations, and assessing physical security controls.

Q42. What is SEH Overwrite Exploits?
Ans: SEH (Structured Exception Handling) Overwrite Exploits involve manipulating the SEH mechanism in Windows applications to gain control over the program’s execution flow. By overwriting the SEH handler’s record with a pointer to malicious code, attackers can redirect the execution path to their payload, potentially leading to arbitrary code execution.

Q43. What is POP POP RET in penetration testing?
Ans: POP POP RET is a stack-based exploitation technique used to bypass security mechanisms like DEP (Data Execution Prevention) and ASLR (Address Space Layout Randomization). It involves popping values off the stack and then using a RET (return) instruction to execute arbitrary code. This technique leverages the stack to set up controlled execution flow to the attacker’s code.

Q44. What is the difference between vulnerability assessment and Penetration Testing?
Ans: Vulnerability assessment involves identifying and classifying security weaknesses within a system or network, usually through automated scanning tools. It provides a list of vulnerabilities but does not involve actively exploiting them. Penetration Testing, on the other hand, goes a step further by actively exploiting identified vulnerabilities to assess their potential impact and effectiveness of existing defenses, often simulating real-world attacks to evaluate security posture.

Q45. Are you familiar with port scanning software tools?
Ans: Yes, I am familiar with various port scanning tools, including:

• Nmap: Widely used for network discovery and security auditing, capable of performing detailed scans and service detection.
• Masscan: Known for its high-speed scanning capabilities, used to scan large networks quickly.
• Netcat: Often used for network diagnostics and simple port scanning.

Q46. How do you pentest with encrypted emails?
Ans: Pentesting with encrypted emails involves:

• Intercepting: Capturing encrypted email traffic if possible.
• Decrypting: Attempting to decrypt the emails using known methods or obtaining decryption keys through other means.
• Analyzing: Once decrypted, analyzing the content for sensitive information or vulnerabilities.
• Testing: Assessing the email handling and encryption implementations for potential weaknesses.

Q47. Have you used automated tools in testing?
Ans: Yes, I have used automated tools for various aspects of testing, such as:

• Burp Suite: For automated web application vulnerability scanning.
• Nessus: For vulnerability assessment and management.
• OWASP ZAP: For automated web security testing. These tools help in quickly identifying vulnerabilities and streamlining the testing process, though manual testing is also crucial for comprehensive assessments.

Q48. What’s most important in data protection?
Ans: The most important aspects of data protection include:

• Encryption: Protecting data at rest and in transit to ensure it is not accessible to unauthorized individuals.
• Access Control: Implementing strict access controls to limit who can view or modify sensitive data.
• Regular Backups: Ensuring data is regularly backed up and can be restored in case of loss or corruption.
• Data Integrity: Ensuring data is accurate and has not been tampered with.
• Compliance: Adhering to relevant regulations and standards to ensure proper data handling and protection practices.

Q49. What’s your experience with a Diffie-Hellman exchange?
Ans: My experience with Diffie-Hellman exchange includes:

• Understanding: Familiarity with its role in securely exchanging cryptographic keys over an insecure channel.
• Implementation: Experience in implementing or reviewing Diffie-Hellman key exchange processes in secure communication protocols.
• Analysis: Assessing the security of Diffie-Hellman implementations and understanding its strengths and vulnerabilities, such as susceptibility to man-in-the-middle attacks if not properly authenticated.

Q50. What is token Impersonation?
Ans: Token Impersonation involves assuming the identity of a legitimate user or system by acquiring and using their authentication tokens or session identifiers. This can allow attackers to gain unauthorized access to resources or perform actions as if they were the legitimate user, leading to potential data breaches or privilege escalation.

Q51. What are some systems where you performed pentesting?
Ans: I have performed penetration testing on a variety of systems, including:

• Web Applications: E-commerce sites, content management systems, and custom applications.
• Network Infrastructure: Corporate networks, firewalls, and VPNs.
• Mobile Applications: Android and iOS apps.
• Cloud Environments: AWS, Azure, and other cloud service platforms.

Click here for more related topics.

Click here to know more about Penetration testing.