External Infrastructure Testing
External infrastructure testing focuses on identifying vulnerabilities in the systems and services that are exposed to the public internet. These may include web servers, email systems, firewalls, VPN gateways or any device or application that can be reached externally. The goal is to assess what an attacker could discover and exploit without needing any internal access to your organisation.
This type of testing replicates the perspective of a real world threat actor scanning the internet for exposed systems and weak points. It provides valuable insight into how well your external defences are configured and whether any overlooked vulnerabilities could put your business at risk.
Why It Matters
Your external infrastructure is often the first point of contact between your organisation and potential attackers. If these systems are misconfigured, unpatched or poorly protected they can be exploited to gain unauthorised access, steal data or act as an entry point for further attacks.
Many organisations are not fully aware of what is exposed to the internet or how it behaves under scrutiny. External infrastructure testing brings clarity to this by identifying weaknesses before they are found and used by someone with malicious intent.
It also supports risk management, compliance and security best practices by providing evidence of how your perimeter defences perform under real conditions.
Key Benefits
Prevent Unauthorised Access
Identifies open ports, outdated software and exposed services that could be targeted by attackers attempting to breach your network.
Improve Perimeter Security
Helps ensure that firewalls, routers and security appliances are correctly configured and not exposing unnecessary services.
Meet Compliance Requirements
Many standards including ISO 27001, Cyber Essentials and PCI DSS require regular testing of external systems to demonstrate good security hygiene.
Understand Your Attack Surface
Provides a clear view of what systems and services are publicly accessible and how they appear to a potential attacker.
How It Is Carried Out
External infrastructure testing is performed remotely without the need for internal access. The tester begins by discovering your organisation’s public facing IP addresses and domains. They then scan for open ports, running services and visible applications to build a picture of your external footprint.
Each identified service is then assessed for known vulnerabilities, weak configurations and authentication issues. The test may include attempts to bypass controls, exploit missing patches or enumerate resources that should not be exposed.
The testing is designed to avoid disruption and is carried out within an agreed scope. Once complete, you receive a detailed report outlining the findings the level of risk they present and clear recommendations on how to address them.
Final Thoughts
External infrastructure testing is a vital part of a robust cyber security strategy. It ensures that your internet facing systems are not leaving the door open to threats and provides confidence that your organisation is properly defending its digital perimeter.
Whether you are a growing business hosting your own services or a larger organisation managing a complex network of online systems, regular testing is essential to stay ahead of evolving threats and maintain trust with clients and partners.