Penetration testing is the process of checking a system’s vulnerabilities or weak spots that can help potential hackers access sensitive data. Its main aim is to simulate the cyber-attack to prevent the occurrence of such malicious incidents by implementing robust security measures.It ensures web applications are safe and do not pose the threat of leaking users’ information.
Among various roles, the Penetration Tester is crucial. They are the ones who find vulnerabilities in a system and prevent cyberattacks of all sorts. That’s the reason many reputable organizations hire penetration testers to conduct fake attacks and identify security issues.
If you are wondering, ‘How can I prepare for the penetration tester interview round in 2025?’ this article will prove very useful. It will help you gain confidence and knowledge. So, read this article and enhance your chances of landing the job. So, without any further ado, let’s get started…
30+ Penetration Tester Interview Questions With Answers [2025]
Here is our list of the top 30+ penetration tester interview questions, especially suited for freshers. The list covers questions about different cyberattack techniques to help you prepare for the interview round. Read on!
1. Define penetration testing in your own words. Why is it important?
Penetration testing, also known as pen-testing, is a type of testing that cyber-security experts often simulate to find and exploit software vulnerabilities. It identifies weak spots in a computer system that cyber attackers exploit to gain unauthorized access to data.
These vulnerabilities often result from coding errors or misconfigurations. Pen-testing often aims to strengthen the system against malicious attacks and prevent organizations from them. It helps organizations prevent malicious attacks, enhance the brand’s value and promote business growth.
2. Which factors make a system vulnerable in your opinion?
➢ In my opinion, the factors that usually make a system vulnerable are:
Complexity in system, software or hardware
Password sharing
Bugs or errors in the system
Insufficient employees’ training
Coding errors
Inappropriate disposal of essential documents
3. What is the difference between a white box, a black box and gray box testing?
White-box testing, also known as glass box texting or transparent testing is a robust tool. It is conducted to analyze the entire internal structure of software, including the data structure, code, internal design and functionality.
Black box testing only examines the functionality of the software. The tester does not evaluate the internal structure of the application in this process.
Gray box testing combines the benefits of both white box and black box testing. It improves the product’s overall quality by debugging software or recognizing vulnerabilities. The tester tests it from the user’s point of view.
4. What are the different penetration testing phases? Describe them in brief.
Penetration testing involves five crucial phases, which include reconnaissance, scanning, gaining access, maintaining access and covering tracks.
In the first phase, the cyber security expert tests the computer system as a hacker and gains unauthorized access to the IP address. The second phase of scanning is crucial to identify potential vulnerabilities and errors or bugs in the system. Gaining access allows them to use malpractices to breach the system.
Maintaining access means stealing sensitive information or data. Finally, the last phase, i.e., covering the tracks, includes the removal of the logging signs. All of the phases are crucial and penetration testers need to be very careful while performing each phase.
5. Explain the meaning of XPath Injection in penetration testing.
XPath injection is a kind of vulnerability that often targets the application’s input process. Often, XPath is used to query XML files or XML databases. More often than not, cyber-attackers manage to control any one part of the XPath query. This infects the data transmitted to the server.
However, by recognizing its signs and implementing data safety measures, penetration testers can create a robust defense against XPath injection attacks.
6. Explain XSS in your own words.
XSS stands for Cross-Site Scripting. It is one of the most common security vulnerabilities that allows cybercriminals to inject malicious code into a reliable website. More often than not, hackers and cyber criminals use this method to gain unauthorized access to the user’s sensitive information. Users are at a higher risk of becoming victims when they visit infected websites.
7. What is the use of w3af in penetration testing?
W3af (Web Application Attack and Audit Framework) is a versatile tool. Penetration testers often use this tool in penetration testing. It allows testers to identify security vulnerabilities within the computer system or web application. By assessing the potential threat, they can implement the right strategies to combat the issue and prevent data theft.
8. Describe the OSI model in penetration testing.
The OSI (Open Systems Interconnection) is a seven-layered conceptual framework. It helps cyber security experts understand how data travels across a structured network. It is one of the most important parts of penetration testing as it helps testers identify potential security vulnerabilities at each layer.
9. What is the meaning of the reflected XSS vulnerability?
A reflected XSS vulnerability, also known as the non-persistent attack, is a type of cyber vulnerability. A malicious script frequently emerges when it reflects off a web application to the browser of the web. Hackers often send a link to activate the script that is commonly reflected on the web page. Consequently, it allows the attacker to enable the execution of malicious code. They run on the web page without being detected.
10. Explain SQL injection. How can you prevent the issue?
SQL injection is a kind of cyber security attack. It simply means to inject a malicious SQL code into the application’s databases. This way, it exploits security vulnerabilities to steal sensitive information. With the help of parameterized database queries, typed parameters and the safe implementation of parameterized databases, software developers can prevent SQL injection.
11. What is the meaning of data packet sniffing?
Data packet sniffing is the process of collecting and analyzing data packets that pass through a network. It helps in the investigation of network traffic to identify strange activities or unauthorized accesses. It can be used for several purposes, including troubleshooting, network monitoring and detecting security risks and vulnerabilities. Penetration testers often utilize this process to identify if any sensitive data is being sent in an unexpected way.
12. What do you know about SEH Overwrite Exploits?
SEH Overwrite Exploit is a kind of security exploit that allows hackers to execute malicious scripts on a computer system or web application. It occurs even though the target system functions normally to read, write and execute permissions. Often, it helps malicious users to implant malware attack to steal data in no time.
13. Explain the term butter overflow. How can developers prevent this risk?
A butter overflow is a common security vulnerability in software development. It usually occurs when attackers inject nefarious codes into an application or program’s buffer or when a program writes more data to a buffer (a temporary storage area in memory) than it can hold. This excess data can overwrite adjacent memory locations, leading to unpredictable behavior, crashes or security vulnerabilities, such as allowing attackers to execute arbitrary code.
There are several methods that can be used to prevent the risk of butter overflow, including using secure coding techniques and programming languages, leveraging tools designed to catch such issues, following end-to-end data encryption practices and space layout randomization.
Whatever the case, preventing buffer overflow vulnerabilities involves adopting best practices. Developers must use safe programming languages, such as Python, Java and C#. These languages provide built-in protections against buffer overflows by managing memory automatically.
In case they use C or C++, they need to be extra careful. Additionally, they should use functions and methods that perform bounds checking to prevent writing outside the allocated buffer. Also, they should use safe functions, like fgets(), strncpy() and strncat(). These functions perform bounds checking.
Furthermore, they should conduct regular code reviews to spot potential vulnerabilities and use advanced tools to detect unsafe code patterns.
Implementing these strategies can help developers significantly reduce the risk of buffer overflow vulnerabilities and improve the security and reliability of their software.
14. Define the meaning of WEP. Why is this method insecure?
WEP (Wired Equivalent Policy) is a wi-fi security protocol that contains security flaws. It is a retired wi-fi security algorithm. It has been deemed unsafe and easy for cyber attackers to crack. It is deemed unsafe because it includes several drawbacks, such as:
Static key: WEP uses a single static key that grants authorization to every connected device. This makes it easy for malicious actors to guess the key and gain access to confidential information.
Small key space: Small key space is yet another reason that makes it unsafe for use.
RC4 encryption: WEP relies on the RC4 encryption algorithm that has been scrutinized for cryptographic weakness.
Limited key sizes: WEP only supports 64-bit or 128-bit encryption key sizes. These key sizes are easier to decrypt compared to larger key sizes.
Limited key characters: WEP keys consist solely of hexadecimal characters, permitting only the digits 0–9 and the letters A–F.
Because of these drawbacks, WEP is deemed unsafe and never recommended for secure wi-fi networks.
15. What is XAMPP?
XAMPP stands for Cross-Platform, Apache, MySQL, PHP and Perl. It is a free and open-source development platform used for hosting websites. The best thing about XAMPP is that it is an intuitive platform that features advantageous options for web developers. Developers can avail of its varied modules and templates to customize their websites.
Moreover, it is useful in creating e-commerce applications, etc. In addition, the use of XAMPP for penetration testing is gaining huge traction globally.
16. What, according to you, is cloud computing? How can it become vulnerable to security threats?
Cloud computing is the process of delivering computing resources over the internet or “the cloud.” It allows storing and accessing databases, programming and applications over the internet. It eliminates the need for a computer’s hard drive for these purposes. It is flexible in nature and allows users to access data from anywhere and at any time. Cloud computing can become vulnerable to security threats in many ways, including:
Improper Configuration: When computing assets are not set correctly, they can become vulnerable to attacks. Unsecured data containers, disabled security controls and excess permissions are some of its examples.
Poor Access Management: If there is no proper management of access points, cyber crooks can do a lot of damage.
Weak security measures: If proper security measures are not taken, it can lead to vulnerabilities and data breaches.
Malware Attack: Hackers often use Malware to steal sensitive data, disrupt business operations or infect other systems connected to the cloud environment.
Account Hijacking: Cyber attackers can use phishing attacks, exploit software vulnerabilities or leverage weak passwords to hijack accounts.
Lack of Data Protection Policies: If organization fail to have robust business data protection policies, they often become target of cyber attackers.
17. Explain Cloud Security Alliance.
Cloud Security Alliance is a non-profit organization that ensures the security and safety of cloud computing practices. For this purpose, it provides resources and guidelines to improve cloud security.
18. Explain SSL Stripping in penetration testing.
SSL Stripping is a type of cyber-attack that allows an attacker to intercept all traffic between the client and server. They often strip the SSL/TSL encryption from an HTTP request before sending it to the web server. This way, they can manipulate data, execute unauthorized transactions or use the account for further attacks.
19. Explain an SSL/TSL connection.
An SSL/TSL connection is a secure communication channel that allows two varied devices to talk over the internet safely. With SSL/TSL certificates, web developers can strengthen end-to-end data encryption using cryptographic algorithms. They ensure privacy and integrity during data transmission over the internet.
20. Explain a Diffie-Hellman exchange.
A Diffie-Hellman exchange, also known as exponential key exchange, is a cryptographic protocol that allows two parties to exchange cryptographic keys securely over a public channel, ensuring zero threat to data privacy and integrity. It relies on discrete logarithm problems and mathematical features of modular exponentiation.
The Diffie-Hellman key exchange is used in many cybersecurity applications, including Public-key infrastructure (PKI), SSL/TLS handshake and Secure Shell Access (SSH).
21. Define token impersonation in penetration testing.
Token impersonation is a cyberattack technique in penetration testing. This technique is used to gain access to sensitive information that is protected by strong passwords or authenticated tokens. It significantly changes the authenticated tokens to breach the data privacy or integrity. Generally, hackers use token impersonation for phishing attacks or social engineering attacks.
22. Explain the meaning of SSHExec.
SSHExec is a remote shell interface that is often implemented in the SSH protocol. It is recognized for a monitored application that has at least one SSH Script attribute group. It indicates that the command that follows the SSHEXEC keyword is remotely started on the SSH target system.
With its support, attackers establish a robust connection between the target system and their systems. This way, they run malicious commands or scripts on that system over SSH.
23. What is enumeration and why is it crucial?
Enumeration is a significant data-gathering process that cyber attackers often conduct to exploit a system’s vulnerabilities. It involves extracting crucial information like user names, system names, network sharing, data transmission and other services. By stealing privileged information about IP addresses and DNS systems, they gain unauthorized access and steal the data.
24. Explain Local File Inclusion.
Local file inclusion, popularly known as LFI, is a technique used to exploit security issues, revealing sensitive information or source code. Often, attackers use it to manipulate input processing to execute malicious files located on the server. This way, they trick web applications which often leads to remote code execution or cross-site scripting (XSS).
25. What is Remote File Inclusion?
Remote File Inclusion or RFI Remote File Inclusion (RFI) is a web application vulnerability. It allows attackers to inject and execute malicious files from a remote server into a target web application. Notably, these files are not part of the tried and tested system or web applications.
This vulnerability typically arises due to improper input validation in the application’s code, particularly when user-supplied input is used to include files. Cyber attackers inject arbitrary script code into web pages in order to steal data and execute actions as authentic users. In some cases, they hack the entire compromised system.
26. How do you do penetration testing?
First off, I analyze the software system to determine which technique I should use to conduct testing. Then, I follow the steps of reconnaissance and scanning to identify the key areas of data vulnerability. Once the scanning is completed, I spend some time identifying the vulnerable data or weak spots to try to hack as much as possible. With this in-depth information, I will determine the best security measures to ensure robust security defense against cyberattacks.
27. Explain Data Execution Prevention in penetration testing.
Data Execution Prevention or DEP, is a crucial data protection technique. This security mechanism prevents code execution from specific regions of memory that are intended to store data, such as the stack or heap. It acts as a safeguard against memory-based exploits, such as buffer overflows, by marking these areas as non-executable.
DEP is an essential security feature in modern operating systems. It helps prevent the execution of malicious code or scripts in the system. Its assessment is a critical part of penetration testing to evaluate how well a system can resist exploitation attempts.
28. Types of DEP.
➢ DEP are of two types:
Hardware-Enforced DEP: Uses processor-level features to mark memory regions as non-executable. It ensures robust protection against unauthorized execution.
Software-Enforced DEP: Focuses on preventing unsafe use of memory at the application level, such as improper function calls.
29. How does DEP work?
➢ Here is how DEP works:
Memory Segmentation: In this phase, DEP separates executable memory (for code) from non-executable memory (for data). Memory regions like the stack and heap are marked as non-executable in this phase.
➢ Enforcement Mechanisms:
Hardware-Enforced DEP: Uses processor features like the NX (No-Execute) bit or XD (Execute Disable) bit to enforce execution restrictions.
Software-Enforced DEP: Prevents dangerous application-level behaviors, such as executing dynamically generated code.
Attack Prevention: If an attacker injects malicious code into a non-executable memory segment, DEP blocks its execution and raises an exception.
30. What is spear phishing? How does it differ from phishing?
Spear phishing is a targeted cyberattack in which a cybercriminal targets a specific individual or group. Malicious actors create personalized emails or messages aimed at specific individuals or organizations. Unlike generic phishing, which involves sending mass emails to a broad audience with the hope of deceiving some recipients into revealing sensitive information, spear phishing is highly customized.
Malicious actors frequently exploit personal information obtained from social media, public records or past breaches to craft messages that seem credible and reliable. This targeted approach increases the likelihood of success, as victims are more likely to believe the communication is genuine.
While phishing casts a wide net to exploit general vulnerabilities, spear phishing narrows its focus, exploiting trust and specific relationships to steal sensitive data, compromise accounts or deploy malware.
Additional Penetration Tester Interview Questions and Answers
31. What is Baiting?
Baiting is a kind of cyber security attack that a scammer uses to lure a victim so that he can fall into a trap. Often, they make false promises to tempt individuals or groups. This way, they inflict the system and steal the financial or personal information.
32. What is GDPR?
GDPR or General Data Protection Regulation is a European Law that governs how organizations should ensure data privacy and integrity while processing and transmitting it. It defines the rights of individuals in the digital age, the obligations of those processing data and how to ensure compliance. Also, it establishes standards for how personal data must be collected, processed and erased.
Let’s now take a look at the FAQs pertaining to Penetration Tester. Read on!
FAQs
Q1. What is the salary of a penetration tester?
The salary of a penetration tester ranges between $102,000 and $117,000, depending on the education, qualifications, experience and location.
Q2. Is penetration testing a hard job?
The answer is yes. Becoming a penetration tester means a deep understanding of IT systems, constant research of new developments in hacking techniques, strong problem-solving skills, effective communication, etc.
Q3. Can a non-IT person become a penetration tester?
Yes, a non-IT person can gain expertise in penetration testing by learning essential technical skills, acquiring relevant certifications and understanding hacking practices and security measures. Though it takes a lot of money, time and effort, a non-IT person can achieve the requisite qualifications with dedication and commitment to learning.
Q4. Will AI take over the roles of penetration testers?
The answer is no. AI will help penetration testers become more advanced in recognizing the system’s vulnerabilities and modern hacking practices. It will save their time and effort by automating repetitive tasks.
Q5. Which organizations hire penetration testers the most?
Organizations across various industries prioritize cybersecurity, which makes penetration testers an essential part of an organization. They not only identify vulnerabilities but also remediate them in a timely manner.
The organizations that hire penetration testers the most include Technology Companies, Financial Institutions, Healthcare Organizations, Government Agencies, E-Commerce Platforms, Telecommunications Providers, Educational Institutions, Cybersecurity Firms, Energy and Utilities Companies and Retail Chains.
The Bottom Line
So, these are the top penetration testing interview questions that you need to prepare in 2025 to excel in your interview. All in all, penetration testing is a crucial profile. It helps identify security flaws, ensuring the system functions as it is supposed to work. Penetration testers play crucial roles in organizations. They are the ones who find vulnerabilities in the web application in the initial stage. A penetration tester plays a crucial role in an organization. They can assist organizations in mitigating the adverse effects of detrimental attacks.
