Before diving deep into the world of penetration testing, it’s essential to understand the concept and how it differs from vulnerability assessment. Many people often confuse the two, thinking they are the same because both involve identifying vulnerabilities and reporting them. While this is partially correct, it doesn’t capture the full picture.

Vulnerability Assessment vs. Penetration Testing

Vulnerability Assessment: A vulnerability assessment focuses on identifying, quantifying, and prioritizing vulnerabilities within a system. This process typically involves:

• Scanning and Identification: Using automated tools to scan systems for known vulnerabilities.
• Reporting: Providing a detailed list of identified vulnerabilities, often categorized by their severity, without necessarily testing how these vulnerabilities could be exploited.

Penetration Testing: Penetration testing, or pentesting, takes the process a step further by simulating real-world attack scenarios. This not only identifies vulnerabilities but also attempts to exploit them to understand their potential impact. Penetration testing involves:

• Simulating Attacks: Emulating the tactics, techniques, and procedures (TTPs) used by malicious actors to exploit vulnerabilities.
• Exploitation: Actively exploiting identified vulnerabilities to gain unauthorized access to systems and data.

In today’s world, where digital transformation is prevalent, organizations are increasingly susceptible to attacks, these threat actors often do not rely on the latest zero-day exploits. Instead, they exploit existing, unpatched vulnerabilities, perform social engineering, and gather information from current or former employees. These attacks can lead to significant data breaches, resulting in the loss of sensitive information and eroding client’s trust. By understanding the nuances of penetration testing, you can better appreciate its role in a comprehensive cybersecurity strategy and the importance of regularly testing and securing your systems against potential threats.

How to conduct a penetration testing and what are the phases involved?

Each organization has a unique approach to penetration testing, with the scope varying according to the client’s requirements. Some organizations only request external penetration testing, which involves researching the company and performing social engineering using Open-Source Intelligence (OSINT) methodologies to gain information and access to critical assets. Conversely, some organizations permit teams to simulate insider threats or rogue employees who have hacking knowledge and access to the organization’s critical infrastructure. In certain instances, testers must also audit the organization’s physical security controls.

Before commencing penetration testing, it is crucial to define the scope and stages involved. Typically, every penetration testing exercise begins with the scoping phase (also known as pre-engagement), where the penetration testing team representative (usually a consultant) meets with the client to identify requirements and define the testing scope. Let’s explore the phases in detail:

Pre-engagement or Scoping: In this phase, penetration testing consultants gather all necessary information from the client regarding the purpose and scope of testing. Based on the defined scope, consultants prepare a quotation, including costs and the estimated man-days required for testing, report preparation, and discussions with the client’s internal security team. Key questions to ask include the organization’s priorities, crown jewel assets, permissions for brute-force or DDoS attacks, and the testing window. The client must sign off on the agreement, ensuring all details are in the contract and that no legal action will be taken against the tester for gaining access to infrastructure and exploiting vulnerabilities. Once contractual formalities are completed, actual testing begins, involving five major phases.

1. Information Gathering or Reconnaissance: This initial and primary phase of penetration testing involves gathering as much information as possible about the organization. This phase is divided into two sub-phases:

a. External Reconnaissance: Testers obtain information about the organization through public repositories, sources, websites, and so on. Typically, testers use OSINT methodologies to identify potential information that can be used to gain access to the organization’s infrastructure or identify sensitive data.

b. Internal Reconnaissance: Testers act as legitimate internal employees of the company, attempting to obtain information such as passwords and sensitive data by traversing the internal network or performing lateral movements within the organization’s infrastructure.

2. Vulnerability Analysis/Scanning: Based on the information gathered in the previous phase, we (testers) develop strategies to penetrate the client’s system. Some consider threat modeling as a separate phase, but I include it as part of vulnerability analysis. During this phase, we use various tools to scan the client’s infrastructure, network, and web applications (depending on the scope) to identify as many vulnerabilities as possible. This involves both manual and automated approaches. We then analyze these vulnerabilities to determine if they are false positives or true positives and prepare a report based on their severity and impact.

3. Exploitation: This is where the actual testing takes place, involving the exploitation of vulnerabilities identified in the previous phase. This phase assesses both the security of the client’s environment and the tester’s skills in performing the exploitation. While some exploits may be publicly available, others may require custom code written by the tester.

4. Post-Exploitation: This crucial phase evaluates the impact of the exploitation. For instance, gaining access to an unused server outside the client’s domain has minimal impact, while accessing a server containing sensitive data like database records and financial transactions is critical and can result in significant financial losses. During this phase, we identify the information held by the compromised server or network device, assess the criticality of the exploitation, and document it in our reports.

5. Reporting: The final and most important part of penetration testing is reporting. If findings cannot be reported clearly, they are of little value. Many testers struggle with effectively communicating their findings. Reports should be tailored to the audience and divided into specific categories:

a. Executive Reports: These are for leadership teams or CEOs and include a high-level summary of the testing, the overall security posture of the organization, the risk profile based on the severity of findings, and strategic recommendations for addressing the issues.

b. Technical Reports: These are for technical teams responsible for remediation and include detailed explanations of the methodologies used during testing. These reports should contain:

i. Screenshots of findings, including requests, responses, and post-exploitation details.

ii. Detailed descriptions of the vulnerabilities identified.

iii. Risk exposure assessments indicating the likelihood and potential impact of the risks.

iv. Recommendations for fixing the vulnerabilities.

v. Steps for post-validation to ensure the issues have been resolved.