The main difference between an internal and external penetration test lies in the starting point and the perspective each type of test takes when assessing an organization's network and systems.
| External Penetration Test | Internal Penetration Test | |
| Objective | Mimics an external attacker trying to gain unauthorized access to the organization's systems from outside the network. | Simulates an insider threat or a scenario where an attacker has already breached the network perimeter. |
| Scope | Focuses on publicly accessible resources, such as websites, firewalls, and other internet-facing systems. | Conducted within the organization’s network, focusing on internal infrastructure like local network systems, internal servers, and employee devices. |
| Goal | Identifies vulnerabilities that could allow an attacker to breach the perimeter defenses and gain initial access. | Identifies vulnerabilities that could lead to privilege escalation, lateral movement, and data breaches. |
| Use Case | Helps to protect against threats like remote attacks, denial-of-service attacks, and breaches from malicious internet users. | Useful for testing threats from insiders, compromised internal devices, or attackers who have already bypassed external defenses. |
Both types are essential for a comprehensive security strategy. External tests focus on preventing initial breaches, while internal tests assess the damage potential if a breach occurs.