External infrastructure testing
See what an attacker can reach.
Test the internet-facing systems that connect customers, staff and suppliers to your business.
Scope a perimeter testIs a management interface reachable from the internet?
An internal administration interface accepts an external connection.
Illustrative test report
- Boundary
- Confirm the owner of the public domain and IP range, supplier approval and the authorised window.
- Decision
- The identified system owner restricts management access to the agreed network.
- Verification
- Check reachability from an external network after the change and record which service was retested.
Example perimeter review
- Discover
- Confirm the approved domains, public addresses and endpoints.
- Test
- Examine exposed services, perimeter controls and remote access.
- Verify
- Retest identified weaknesses after your team applies fixes.
Prepare for this engagement
When it is useful
A VPN gateway is replaced, a new public service goes live or you need to check how an acquired business is exposed.
What to bring
For the public management-interface example, identify who owns the domain and each IP range. Confirm who operates the VPN or hosting gateway, which addresses the supplier has authorised, the testing window and the contact who can stop the work. Exclude shared infrastructure unless its owner grants permission.
What you receive
Findings identify the exposed asset, evidence of reachability and the remediation owner. A retest checks the affected service after the change.
Starting from an existing staff or contractor connection? Choose internal network testing. To examine a guest device’s access from a named site, choose wireless network testing.
Get a faster, clearer, and simpler view of your external infrastructure vulnerabilities
Your perimeter (firewalls, routers, VPN gateways and web servers) is what separates your internal network from the public internet. These assets come under regular scrutiny by attackers probing defences and looking for misconfigurations, weak encryption, or default credentials.
While mistakes can happen, continuous external infrastructure penetration testing is the best way to quickly surface them to ensure your external attack surface remains resilient and well protected.
What is involved in an external infrastructure pen test?
Our CREST certified penetration testers conducts manual and automated security assessments to simulate real-world attacks, while ensuring not to impact day-to-day operations.
Our Comprehensive Approach: Exposure Analysis & Active Exploitation
- Confirm ownership of the domains, public IP ranges and hosted systems first. Discovery identifies reachable services. Testers then assess selected attack paths, such as whether a remote administration service can be reached outside the intended network.
- Active exploitation is where we attempt controlled, human-led exploits against identified targets, testing for vulnerabilities such as misconfigured firewalls, unpatched services, weak TLS settings and default credentials to confirm real-world risk.
Combining exposure analysis with active exploitation testing provides a thorough understanding of your external attack surface, covering both visibility and exploitability.
What the perimeter test covers
Network Reconnaissance & Enumeration
Gather information on IP ranges, open ports, DNS entries and service banners to build an accurate map of your external footprint.
Perimeter Firewall & VPN Testing
Verify rule sets, ACLs and VPN configurations to ensure only intended traffic is allowed into your network.
Web & Application Server Hardening
Test internet-facing servers for missing patches, directory listing, default credentials and insecure service configurations.
Network Services & Protocol Analysis
Examine services such as SSH, RDP, SMB, SNMP and DNS for weak authentication, exposure of sensitive information and susceptibility to known exploits.
Cloud Endpoint & API Exposure
Assess public cloud services like load balancers, storage buckets and management APIs for misconfigurations that could leak data or grant unauthorized access.
Wireless & Remote Access Security
Evaluate secure configuration of wireless gateways, VPN concentrators and remote desktop gateways to prevent credential theft and unauthorized entry.
Benefits of external infrastructure penetration testing
Strengthen your organisations’ security posture
Early detection of errors and vulnerabilities prevents data breaches, financial loss, and service disruption.
Having a trusted third party assess your external infrastructure is also an invaluable training and continuous improvement tool for internal teams as it:
- Provides actionable recommendations to fix vulnerabilities and improve security practices.
- Helps teams adopt better security controls, patch management, and monitoring practices.
- Validates if networks are segmented securely into subnetworks to protect critical business assets.
External Infrastructure Penetration Testing FAQs
What is continuous external infrastructure penetration testing?
A penetration test examines an agreed scope during a defined window. Recurring scans identify changes between tests; a new service, firewall change or remote-access deployment may justify another hands-on test. Agree the timetable rather than assuming all perimeter addresses are tested continuously.
Why is continuous testing important?
The external threat landscape evolves rapidly, with new vulnerabilities and attack methods emerging daily legacy periodic assessments are no longer enough. Continuous external infrastructure penetration testing ensures that your perimeter security is consistently validated, helping to prevent breaches and reduce risk.
Which systems are tested?
We can include any system that is exposed to the internet in the scope for an external infrastructure penetration test, including web applications, email servers, VPN gateways, DNS servers, firewalls, and cloud infrastructure. The testing focuses on the systems that could serve as an entry point for attackers.
Will I get a report?
Yes you will receive a report, however results (particularly high / critical findings) are communicated to you well in advance of that – often within hours of discovery. When you receive your report it will formally detail identified vulnerabilities, risk ratings, remediation guidance, and trends over time, helping you strengthen your security posture and demonstrate compliance.
How do I get started?
Simply contact our security team to discuss your infrastructure, goals, and preferred testing schedule. We tailor our service to your environment and provide a clear roadmap for improving your external security.