Types of Penetration Testing: Which One Does Your Business Need?

Cybersecurity isn’t just about compliance checklists or antivirus software anymore. Businesses are dealing with increasingly advanced threats, and attackers are not bound by boundaries or playbooks. They’ll go after weak credentials, misconfigured servers, exposed APIs, and even unsuspecting employees.

Penetration testing, when done right, offers critical insight into where your real-world exposures lie. But not all testing methods serve the same purpose. There are various types of penetration testing, each focusing on a specific layer, asset, or threat vector.

This blog will unpack these types of pentesting, help you understand how they differ, and guide you toward selecting the right one for your risk profile and business model.

What is Pentesting

Pen test is an ethical cybersecurity scan with the goal of identifying, exploring, and remediate weaknesses within a company’s network or applications. Pen testing utilizes the same tactics, techniques and procedures (TTPs) that cyber criminal hackers use to mimic a real attack on an organisation, allowing them to determine if their security controls are strong enough to repel various types of threats.

Pen testing can mimic any number of different attack vectors, depending on whether externally or internally run. The objective and outcome of each pen test is dictated by the requirements of the organisation in question. How much information is provided to the penetration tester on the environment or systems they are set to test is dictated by the type of test.

In summary, whereas in white box penetration testing the tester will know everything about the network and systems, with grey box penetration testing, the tester is only provided with a restricted level of information. The tester has no information at all in a black box penetration test, to mimic the actions of an actual attacker.

Also Read: Decoding the Penetration Testing Process​: A Step-by-Step Guide

Penetration Testing Approaches

Certainly! Let’s dive deeper into the testing approaches, Black Box, White Box, and Grey Box to understand how they each work, when to use them, and their strengths and weaknesses in penetration testing.

1. Black Box Testing

What It Is:

In Black Box testing, the tester has no prior knowledge or access to the internal systems of the target organization. This simulates how an external attacker would approach the system, without any inside information. The tester doesn’t know about the network architecture, the software, or the internal controls. They are essentially trying to exploit vulnerabilities from a completely external perspective.

When to Use:

• Real-World Attack Simulation: This is the closest type of testing to how an external threat actor (like a hacker or cybercriminal) would approach your systems.
  
• External Exposure Testing: It’s particularly useful for testing websites, networks, or applications that are publicly accessible over the internet, such as your company’s website or web applications.
  
• Compliance: This type of testing may be required for compliance with regulations that focus on external-facing vulnerabilities, such as PCI DSS for payment card systems.
  

Strengths:

• Mimics how a hacker without insider access would attack.
  
• Tests external defenses, such as firewalls, intrusion detection systems, and exposed services.
  
• Highly useful for identifying easily exploitable vulnerabilities visible to the public.
  

Limitations:

• Lack of access to internal infrastructure means the tester might miss vulnerabilities that only arise when an attacker has deeper access.
  
• It can be time-consuming and might require multiple iterations to discover deeper or harder-to-reach flaws.
  

2. White Box Testing

What It Is:

In White Box testing (also known as Clear Box or Transparent Box testing), the tester is given full access to the organization’s internal systems, source code, network architecture, and security controls. This method allows the tester to perform a thorough examination with complete visibility into the system’s workings. The goal is to conduct an in-depth audit of the infrastructure, applications, and security policies.

When to Use:

• In-Depth Security Audits: Ideal for performing comprehensive security audits on systems, networks, or codebases where deep insights into security posture are needed.
  
• Code Review: Perfect for testing the security of custom-developed software by reviewing source code for flaws or vulnerabilities.
  
• Compliance and Standards: White Box testing is often used to verify that security controls meet internal or regulatory standards, such as ISO 27001, SOC 2, or HIPAA.
  

Strengths:

• Provides an exhaustive review of the system’s architecture, making it easier to find hidden vulnerabilities (e.g., in the source code, configurations, or internal communications).
  
• Reduces the likelihood of missing critical flaws, as it allows testers to explore all aspects of the system in detail.
  
• Ideal for organizations seeking to identify vulnerabilities early in the development lifecycle or after major code changes.
  

Limitations:

• It requires a lot of time and expertise because the tester has to analyze vast amounts of internal data.
  
• While it’s more comprehensive, it’s not as representative of a real-world external attack, since attackers typically don’t have full access to your systems.
  
• High risk of bias if testers assume the organization’s internal security is strong and overlook weak spots that may not be obvious.
  

3. Grey Box Testing

What It Is:

In Grey Box testing, the tester is given limited access or credentials, typically from a non-administrative user or a specific role within the organization. This testing approach strikes a balance between Black Box and White Box testing, offering some internal insight while maintaining a realistic external perspective. Often, the tester may be given access to certain aspects like user credentials or an internal network segment, but not full access to everything.

When to Use:

• Realistic Attack Simulation: Useful when an attacker has gained limited access to the network, such as through phishing or by exploiting a weak internal password. It simulates the experience of an attacker who has compromised a low-privilege account and is attempting to escalate privileges or pivot through the network.
  
• Vulnerability Discovery and Exploitation: This type of test is perfect when you want to see if an attacker with limited access can exploit vulnerabilities in your infrastructure or applications to escalate their privileges.
  
• Cost-Effective and Comprehensive: Grey Box testing provides a good balance between comprehensiveness and resource allocation, as it’s often more cost-effective than a full White Box audit while being more realistic than Black Box testing.
  

Strengths:

• Offers a more balanced and realistic view of vulnerabilities that might be exploited by a low-level insider or an external attacker who has already breached the perimeter.
  
• More cost-effective than White Box testing while still being thorough enough to identify high-impact vulnerabilities.
  
• Great for identifying both external vulnerabilities and internal weaknesses that could lead to privilege escalation.
  

Limitations:

• Doesn’t provide the same deep dive into systems as White Box testing, so it may miss vulnerabilities only visible with full access.
  
• The limited scope can leave some gaps if not carefully scoped, especially if the access given is too restricted.
  

Types of Penetration Testing

Here’s an in-depth look at the core types of pentesting that organizations commonly use:

1. Network Penetration Testing

Network penetration testing mimics actual attacks upon the network infrastructure of a business to locate potential weaknesses that would be used by attackers. This testing addresses both internal and external networks, discovering hidden threats to routers, switches, firewalls, and other network resources.

What It Tests:

• Public-Confidential Network Exposures: It involves probing IP addresses, ports, and services exposed on the internet. For instance, attackers can scan for externally facing unpatched vulnerabilities.
• Internal Network Risks: Once inside the network, it is possible for testers to verify weaknesses in internal systems, e.g., insecure communications or poor access controls.
• Segmentation Issues: Network penetration testing verifies whether various segments of the network (for example, HR, Finance, and Engineering) are correctly segregated to secure lateral movement.
• Unsecured Protocols: It verifies outdated or inadequately configured network protocols like FTP, Telnet, or SNMP, which could be susceptible to attack.

When to Use:

• External Security Audit: When there is new infrastructure deployment or in periodic audits.
• Internal Assessments: When a company suspects its internal network may be at risk because employees or third-party vendors have access.
• Mergers or Acquisitions: To evaluate new network infrastructure and identify vulnerabilities.

Industries That Use It:

• Banking & Financial Institutions
• Healthcare Providers
• Retail and E-commerce

2. Testing for Web Application Security

Web application penetration testing is aimed at diagnosing possible traps in web applications or websites that can be abused. This is very critical because modern enterprises have greatly integrated online platforms into their daily operations. 

What It Tests:

• The OWASP top ten issues: This contains issues such as SQL Injection (SQLi), Cross-Site Scripting (XSS), Cross-Site Request Forgery (CSRF), and Security Misconfiguration.
• Authentication and Authorization Issues: Tests look at flaws in login mechanisms, session management, and privilege escalation vulnerabilities. 
• API Security Issues: For applications that engage with other applications or databases, the safety of the involved Application Programming Interface must be tested for issues such as improper input validation, rate limit, and access control inadequacies. 
• Flaws in business logic: They can be of great significance like improper e-commerce web checkout processes or wrong user role assignments in enterprise applications.

When to Use:

• Before Launching a Web Application: Make sure the app is secure and not exploitable from the outset.
• After Major Updates: A major update to your app’s code or functionality requires reassessment of its security stance.
• Regular Security Audits: To remain ahead of the curve in terms of new threats and patch vulnerabilities prior to exploitation.

Industries That Use It:

• SaaS Providers
• E-commerce Businesses
• Government Agencies

3. Mobile Application Penetration Testing

Mobile application penetration testing evaluates the security of mobile apps (Android and iOS) and their backend services. It includes both the mobile device security and the app’s interactions with its supporting infrastructure.

What It Tests:

• Insecure Data Storage: Ensures that sensitive data like passwords, tokens, or encryption keys are not stored insecurely within the app (e.g., in plain text).
  
• Improper Use of Platform-Specific Features: Includes testing for issues like improper use of the Android Intent or Apple’s Keychain.
  
• API Interactions: Testing the APIs that the app interacts with, focusing on authentication, data integrity, and encryption issues.
  
• Reverse Engineering: Analyzing how easily an attacker could reverse engineer the app’s code to identify vulnerabilities.
  
• Weak Session Management: Examining how user sessions are handled, ensuring that session tokens are not guessable and are stored securely.

When to Use:

• Before Launching Mobile Apps: Ensures that apps are secure before users download them.
  
• During OS Updates: When updates to mobile operating systems (iOS, Android) are released, re-testing ensures compatibility and security.
  
• For Highly Sensitive Apps: Apps in banking, healthcare, or e-commerce require frequent security checks.

Industries That Use It:

• Fintech Companies
  
• Healthtech and Medical Applications
  
• Mobile Games and Social Apps

4. Cloud Penetration Testing

Cloud penetration testing focuses on the security of cloud environments and infrastructure. This type of testing looks for vulnerabilities within the cloud configuration itself, including misconfigurations, improper access management, and flaws in the cloud applications or services being used.

What It Tests:

• Cloud Misconfigurations: Many cloud environments (AWS, Azure, GCP) are complex, and simple mistakes can lead to serious vulnerabilities. Examples include overly permissive security group settings or unsecured storage buckets.
  
• IAM (Identity and Access Management) Issues: Tests the management of user privileges and access to critical cloud resources.
  
• Shared Responsibility Model Failures: Cloud providers and customers share security responsibilities. This test ensures the customer secures the right areas of their cloud infrastructure.
  
• API Security: Just like with web apps, APIs are crucial in cloud setups and need to be secured from threats such as API abuse and unencrypted communications.

When to Use:

• Before Cloud Migration: Cloud infrastructure must be secure before a company moves sensitive data or operations into it.
  
• During Regular Cloud Security Reviews: To ensure cloud resources are continuously secured as new services are introduced.
  
• When Expanding Cloud Infrastructure: Additional resources or services in the cloud should undergo security testing before going live.

Industries That Use It:

• Tech Startups
  
• E-commerce
  
• Enterprises with Multi-Cloud Environments

5. Wireless Penetration Testing

Wireless penetration testing focuses on evaluating the security of wireless networks within an organization. It involves testing Wi-Fi networks, routers, and devices for vulnerabilities that could allow unauthorized access.

What It Tests:

• WPA/WPA2 Security: Ensuring the Wi-Fi network uses strong encryption protocols.
  
• Rogue Access Points: Identifying unauthorized access points that attackers might use to access the network.
  
• WPS (Wi-Fi Protected Setup) Weaknesses: Weaknesses in WPS that can be exploited to gain unauthorized access to the network.
  
• SSID and Signal Leakage: Ensuring sensitive network information isn’t exposed outside the office or facility.
  
• Man-in-the-Middle Attacks: Ensuring that attackers cannot intercept communication between devices and routers.

When to Use:

• Corporate Offices with Wi-Fi Networks: Regular checks for unauthorized access points or weak security.
  
• Retail Locations with Public Wi-Fi: Ensuring customer Wi-Fi access is isolated from internal networks.
  
• Campus Environments: Educational institutions should routinely test for wireless network vulnerabilities.

Industries That Use It:

• Education
  
• Retail
  
• Corporate Campuses

6. Physical Penetration Testing

Physical penetration testing simulates an attacker’s physical attempt to gain unauthorized access to a building or office space. This test assesses physical security measures like entry points, locks, badge systems, and security personnel response.

What It Tests:

• Tailgating: Testing if attackers can gain entry by following authorized employees.
  
• Physical Access Control: Evaluating the strength of locks, door controls, and security features like keycards or biometric systems.
  
• Unsecured Areas: Identifying vulnerable physical assets such as data centers, printers, or servers in unmonitored locations.
  
• Improperly Secured Devices: Checking whether sensitive equipment like laptops or phones are left unsecured.

When to Use:

• When Protecting High-Value Assets: For businesses with sensitive intellectual property or high-value physical infrastructure.
  
• During Security Audits: Regular checks to assess physical security measures.
  
• In Critical Infrastructure Sites: When the physical safety of employees, devices, and equipment is a priority.

Industries That Use It:

• Government Agencies
  
• Pharmaceutical Companies
  
• Defense Contractors

Types of Penetration Testing Offered by Strobes

Strobes Security offers a variety of penetration testing services to address different layers of an organization’s security posture. These tests are designed to identify vulnerabilities and help organizations strengthen their defenses. Below are the key types of pentesting offered by Strobes:

Conclusion:

Understanding the right types of penetration testing is crucial for a strong cybersecurity strategy. Whether you need to test your network, web applications, or physical security, each test uncovers key vulnerabilities that can prevent attacks.

At Strobes Security, we offer tailored penetration testing to help you identify and fix vulnerabilities before they’re exploited. Our expert team uses advanced tools to ensure your systems and data are secure.

Ready to boost your security? Book a demo with us today for a custom penetration testing solution that fits your business needs.

Related Reads:

1. Decoding the Penetration Testing Process​: A Step-by-Step Guide
2. Why Penetration Testing Is Important: Enhancing Security & Reducing Cyber Risks
3. Strobes Penetration Testing Compliance For Audits and Assessments
4. Strobes 2023 Pentesting Recap: Trends, Stats, and How PTaaS is Transforming Cybersecurity
5. How much does a penetration test cost?
6. Solution: Web Application Pentesting
7. Solution: Pentesting as a Service