Pentesting, or penetration testing, is a process of simulating cyberattacks on a system or network to identify and exploit security vulnerabilities. Pentesting can help organizations improve their security posture, comply with regulations, and prevent data breaches.
But not all pentests are the same. Depending on the scope and objectives of the test, pentesters can perform different types of pentests, such as web application pentests, network pentests, wireless pentests, social engineering pentests, and more.
One of the most common ways to categorize pentests is by the perspective of the attacker: internal or external. In this blog, we will explain what internal and external pentesting are, how they differ, and why you need both to secure your systems and data.
What is Internal Pentesting?
Internal pentesting is a type of pentest that simulates an attack from an insider threat, such as a disgruntled employee, a compromised user account, or a malicious visitor. Internal pentesters have some level of access to the target system or network, such as a valid username and password, a VPN connection, or a physical access to the premises.
The goal of internal pentesting is to assess the security of the internal network and systems, and to determine how far an attacker can escalate their privileges and access sensitive data or resources. Internal pentesting can also help identify misconfigurations, weak passwords, outdated software, and other common vulnerabilities that can be exploited by insiders.
Some of the techniques that internal pentesters use are:
- Enumeration: Gathering information about the target system or network, such as users, groups, services, shares, etc.
- Lateral movement: Moving from one system or network segment to another by exploiting vulnerabilities or credentials.
- Privilege escalation: Gaining higher privileges or access rights by exploiting vulnerabilities or misconfigurations.
- Data exfiltration: Stealing or leaking sensitive data from the target system or network.
What is External Pentesting?
External pentesting is a type of pentest that simulates an attack from an outsider threat, such as a hacker, a competitor, or a nation-state actor. External pentesters have no prior access to the target system or network, and they rely on publicly available information and tools to launch their attacks.
The goal of external pentesting is to assess the security of the external-facing assets and systems, such as websites, web applications, email servers, firewalls, routers, etc. External pentesting can also help identify vulnerabilities that can be exploited by outsiders to gain initial access to the internal network or systems.
Some of the techniques that external pentesters use are:
- Reconnaissance: Gathering information about the target system or network, such as domain names, IP addresses, open ports, services, etc.
- Scanning: Scanning the target system or network for vulnerabilities using automated tools or manual methods.
- Exploitation: Exploiting the identified vulnerabilities to gain access to the target system or network or to execute malicious code.
- Pivoting: Using the compromised system or network as a base to launch further attacks on other systems or networks.
Why Do You Need Both Internal and External Pentesting?
Both internal and external pentesting are important for ensuring the security of your organization’s systems and data. By performing both types of pentests regularly, you can:
- Identify and fix security vulnerabilities before they are exploited by real attackers.
- Test your security controls and policies from different perspectives and scenarios.
- Comply with industry standards and regulations that require periodic pentesting.
- Enhance your security awareness and culture among your employees and stakeholders.
- Protect your reputation and brand from potential damage caused by data breaches.
However, not all pentests are created equal. To get the most value out of your pentests, you need to:
- Define clear scope and objectives for each pentest based on your risk assessment and business needs.
- Choose qualified and experienced pentesters who can perform comprehensive and realistic tests using ethical hacking methods.
- Review and validate the findings and recommendations from each pentest report and prioritize remediation actions accordingly.
- Follow up with retesting and verification to ensure that the identified vulnerabilities are fixed and no new ones are introduced.