Types of Penetration Testing – Black, White, and Grey box testing

Types of Penetration Testing – Black, White, and Grey box testing

Table of Contents

With types of penetration testing, there is often a bit of confusion. Some say penetration testing types are black, white, and grey-box penetration testing. While others say application, network, cloud, API, and IoT penetration testing. Nevertheless, all of these are correct to some extent.

The black, white, and grey box testing are mainly the approaches to penetration testing. The application, network, and cloud are the assets on which penetration testing is done.

Regardless of the actual types, it is important to know that all types of penetration testing are conducted for one purpose only – to identify vulnerabilities and their impact. Organizations can choose to perform one or multiple types of pen testing (depending on their business and priority asset) to prevent cyberattacks.

In this blog, we are going to discuss different types of penetration testing, why they are conducted, and how they differ from each other.

What Exactly is Penetration Testing?

Penetration testing, a.k.a pentesting or ethical hacking is the process of purposefully breaching a system’s security to find vulnerabilities.

In most cases, both human and automated tools research, plan, and attack the given environment using various methods and channels. Once inside the environment, penetration testers will check exactly how deep they can get into it with the ultimate goal of achieving full access.

While this process may sound weird, it’s a growing and important trend. Some of the biggest organizations around the world use this method to stay one step ahead of cybercriminals. By purposefully attacking your own application or network, you can discover security weaknesses before a hacker does and attempts a potential breach.

Penetration Testing is Performed To:

  • Find vulnerabilities in digital systems (applications, networks, etc.)
  • Determine the impact level of each vulnerability
  • Check the effectiveness of the current security measures
  • Comply with data privacy and security regulations (PCI DSS, SOC 2, ISO 27001, GDPR, etc.)
  • Get practical ways that improve the overall security posture
Cybercrime graph in USA

Who are Penetration Testers?

Penetration testers or pen testers (a.k.a ethical hackers) are trained and certified in many technical and non-technical skills that allow them to ethically and professionally test clients’ digital assets. Unlike bug bounty testers, pen testers usually work full-time rather than as freelancers.

Additionally, you can often see a specialized penetration testing team in cybersecurity companies, made up of different testers with different skill sets.

Pen testers have a deep understanding of multiple programming languages, along with coding and network protocols. They are also armed with certain soft skills to complete assignments, for example critical thinking and creative problem-solving.

Common Certifications of Pen Testers Include:

  • Certified Ethical Hacker (CEH)
  • Offensive Security Certified Professional certification (OSCP)
  • Certified Information Systems Security Professional (CISSAP)
  • CompTIA PenTest+

Different Types of Penetration Testing – Areas

Before selecting a suitable provider, you need to be familiar with the various types of penetration testing available, so that you can decide which one to choose.

Each type of penetration test requires specific knowledge, methodologies, and tools to perform. Moreover, the goals could range from identifying flaws in the code to meeting regulatory compliance.

Different Types of Penetration Testing

1. Application Penetration Testing

It has two types – web application penetration testing and mobile application penetration testing.

Web application penetration testing is assessing websites and custom applications to uncover flaws in the coding, design, and development that hackers could exploit. The penetration testers look for vulnerabilities like SQL injection, cross-site scripting (XSS), and encryption errors.

Mobile app penetration testing is testing Android, iOS, and other OS mobile apps for authentication, authorization, data leakage, and session handling issues. It is done to check how secure mobile apps are against data theft and unauthorized access.

2. Network Penetration Testing

Network penetration testing uses various ethical hacking techniques to identify any vulnerabilities present in the organization’s network and its security measures. If hackers successfully penetrate an organization’s network, they can get access to particularly any digital assets.

The pen testers try to simulate real attacks to get behind the firewall of the network. They check for vulnerabilities like denial of service (DDoS) attacks, domain name systems (DNS), and SQL injection. Organizations use pentest reports to check whether their network infrastructure is strong enough to avoid cyberattacks.

Want to see a real penetration testing report? Just tap the link below and download it immediately!


Latest Penetration Testing Report


3. Cloud Penetration Testing

Cloud penetration testing examines the security of cloud-native services, configurations, cloud system passwords, cloud encryption, applications, APIs, databases, and storage access for potential vulnerabilities.

After examining, the testers provide a report. It contains the vulnerabilities detected with actionable remediation steps. Companies then use this report to improve the security measures of their cloud infrastructure.

Around 94% of companies use cloud services globally. As a result, it makes the cloud a prime target for cybercriminals. Cloud pentesting helps organizations:

  • Improve overall cloud security
  • Avoid data breaches
  • Achieve compliance
  • Better understanding of the shared responsibility model and cloud assets

4. API Penetration Testing

API penetration testing means evaluating the security of an API of all types (REST, SOAP, and GraphQL) by simulating real attacks. It aims to identify all the vulnerabilities on the server side and in all the API’s components and functionalities. The API pentest report consists of all the vulnerabilities discovered, their impact level, and corrective measures.

By conducting regular pen tests, organizations can then reduce security breaches and ensure the security of sensitive data present in the APIs. Additionally, it can ensure that the API is functioning the way it is intended to.

Common API security threats include:

  • Broken authentication
  • Lack of rate limiting
  • Broken function level authorization
  • Injection attacks (SQL, SSTI, commands, etc.)
  • Mass Assignment
  • DDoS attacks
  • Insufficient authentication policies

5. IoT Penetration Testing

IoT penetration testing replicated real-world cyberattacks on Internet of Things (IoT) devices and networks to find security flaws. The techniques used in IoT pentesting include analyzing network traffic, exploiting vulnerabilities in IoT web interfaces, and reverse-engineering the device’s firmware.

Since more organizations and individuals use IoT devices, penetration testing checks and help in strengthening the security of these devices from cyber criminals.

IoT Penetration Testing can detect the following security threats:

  • Weak passwords
  • Insecure network services
  • Broken ecosystem interfaces
  • Inadequate secure update mechanism
  • Outdated components
  • Lack of privacy
  • Insecure data transfer and storage
  • Lack of physical hardening

6. AI/ML Penetration Testing

AI/ML penetration testing involves evaluating the security of artificial intelligence and machine learning applications (such as ChatGPT). These systems, which often make critical decisions based on data, can be vulnerable to unique security threats.

Penetration testing for AI/ML systems aims to identify and exploit weaknesses in the algorithms, data, and models used by these systems.

Common tests include:

  • Data Poisoning: Introducing false data to trick the system.
  • Model Evasion: Altering inputs to bypass the AI’s detection.
  • Adversarial Attacks: Adding subtle changes to input data to mislead the system.

By performing AI/ML penetration testing, organizations can understand the security flaws in their AI/ML systems and take steps to protect against potential threats. As a result, it helps ensure that AI/ML systems operate safely and reliably.

3 Approaches to Penetration Testing

Based on the information provided to the pen testers about the environment being tested, penetration testing can be then divided into 3 approaches/types:

  • Black box penetration testing
  • White box penetration testing
  • Grey box penetration testing
Aspect Black-Box Pentesting White-Box Pentetsing Gray-Box Pentesting
Knowledge of System No knowledge Full knowledge Limited knowledge
Tester’s Perspective External attacker Insider or developer Authorized user with limited access
Access Level No internal access Complete access, including source code Limited access, typically some internal insights
Scope Focuses on external vulnerabilities and exploits Comprehensive, including internal vulnerabilities Equal focus on both external and internal threats
Time Required Generally longer, due to no prior information Shorter, as testers have complete information Moderate time, depending on the level of access provided
Cost Mostly lower, due to less detailed testing Often higher due to detailed and thorough analysis Moderate cost
Detection of Issues External threats, misconfigurations, and open ports Code-level vulnerabilities, logic flaws, and hidden backdoors Configuration issues, access controls, and data leaks

1. Black-Box Pen Testing

In black-box pen testing, the tester has no information about the system that is going to be tested, not even the application type of operating system. The testers use the same technique and approach that a hacker would take to attack the system.

It is the most challenging type of penetration testing and requires a high level of skill set. It often uses the same resources that would be available to a real attacker. Black box pentesting is the best way to test the overall security of a system.

2. White-Box Pen Testing

White box testing is a process of penetration testing where the tester has complete knowledge of the system, including the source code and access controls. It is usually done by the in-house testing team or the developers themselves.

White box testing focuses on checking whether the applications work the way they are supposed to. It doesn’t exploit any vulnerabilities but rather checks how the program works.

3. Grey Box Pen Testing

It is the combination of both black-box and white-box penetration testing. In grey-box pen testing, the testers have partial knowledge of the target environment in terms of source code, network infrastructure, and partial access to the internal network.

Grey-box testing is the best way to test the system for both insider and outsider threats. It is typically done in the early stages of a program to check what vulnerabilities could be present and how much information a hacker could potentially get.

How Often Should You Perform Penetration Testing?

Penetration testing should be performed regularly – at least once a year – to ensure more consistent IT and network security management. Additionally, it is essential to understand how newly discovered threats or emerging vulnerabilities could be exploited by hackers.

Additionally, data privacy laws and regulations require organizations to conduct security testing on a regular basis. Along with this, penetration tests should be conducted when:

  • New applications, software, or network infrastructures are added
  • Significant changes or upgrades are done to the applications
  • You move the network or servers to a new office location
  • New security patches are applied
  • End-user policies are changed


If a hacker gains access to your networks or applications, then they could indirectly own your operation. Imagine the impact it will have on your customers, partnerships, and business. The primary goal of penetration testing is to expose weaknesses and vulnerabilities in your digital assets so that they can be quickly addressed. With the types of penetration testing mentioned in this blog, you can now choose what type of pen test to go for.

But, before choosing a penetration test service provider, it’s important to ensure that the company has the required expertise to detect a wide range of vulnerabilities. Additionally, they should be able to assist you to remediate them as quickly as possible.

If you want to conduct penetration testing for your business, choose Qualysec. We are one of those rare companies that follow hybrid process-based penetration testing methods. Whether it’s your applications, network, cloud, or AI application, we will uncover all the vulnerabilities that could be a potential cyber threat. Click the link below and talk to our expert now!


Talk to our Cybersecurity Expert to discuss your specific needs and how we can help your business.



Q: What are the stages of penetration testing?

A: The 8 stages of penetration testing are:

  • Information gathering
  • Planning/scoping
  • Automate vulnerability scanning
  • Manual penetration testing
  • Reporting
  • Remediation
  • Retesting
  • LOA and Security certificate

Q: What are the top penetration testing methodologies?

A: The top penetration testing methodologies are:

  • Open-Source Security Testing Methodology Manual (OSSTMM)
  • Open Web Application Security Project (OWASP)
  • National Institute of Standards and Technology (NIST)
  • Penetration Testing Execution Standard (PTES)
  • Information System Security Assessment Framework (ISSAF)

Q: What is basic penetration testing?

A: A penetration testing (or pen test) is an authorized simulated attack on systems to evaluate their security. Penetration testers use the same channels and tactics as an attacker to find the weaknesses in their security measures.

Q: Which tool is used for penetration testing?

A: The best tools for penetration testing are:

  • Metasploit
  • Wireshark
  • Burp Suite
  • Nmap
  • PACU
  • W3af
  • Nikto


Pabitra Kumar Sahoo

Pabitra Kumar Sahoo

Pabitra Sahoo is a cybersecurity expert and researcher, specializing in penetration testing. He is also an excellent content creator and has published many informative content based on cybersecurity. His content has been appreciated and shared on various platforms including social media and news forums. He is also an influencer and motivator for following the latest cybersecurity practices.

Leave a Reply

Your email address will not be published. Required fields are marked *