External Network Penetration Testing
Your perimeter looks secure. Let's prove it.
External Network Security Testing
What is external penetration testing?
Securing your external network involves protecting the systems and services that are exposed and accessible from the internet. This includes firewalls, network gateways, remote access services, and any infrastructure that forms your organisation’s external attack surface.
Because these systems are publicly reachable, they are continuously probed by attackers looking for misconfigurations, exposed services, and known vulnerabilities. A single weakness on the perimeter can provide an entry point into internal systems or sensitive data.
External network penetration testing, sometimes called an external pentest or external network pentest, simulates real-world attacks against your internet-facing infrastructure to identify what an attacker could discover and actually exploit. The goal is not just to find vulnerabilities, but to understand exposure, validate risk, and prioritise remediation based on real impact.
Who Needs This
Who needs external penetration testing?
If your organisation has any systems or services accessible from the internet, those assets are continuously probed by automated scanners and opportunistic attackers. External network testing is essential for any organisation with an external attack surface .
Organisations with remote access services
VPNs, RDP, and SSH are common targets for brute force, credential stuffing, and exploitation of known vulnerabilities. Exposed management interfaces are among the most frequently exploited entry points.
Businesses hosting public-facing infrastructure
Web servers, mail servers, DNS, and cloud-hosted assets all form part of your external attack surface. Each needs to be assessed from the same position an attacker would take.
PCI DSS, ISO 27001, and Cyber Essentials Plus
Multiple frameworks require regular external penetration testing as evidence of independent security assurance. We provide documentation and methodology notes that satisfy QSA and auditor requirements.
Organisations preparing for internal testing or red teams
Understanding your external attack surface and remediating known weaknesses before an internal engagement or red team exercise leads to more realistic and valuable results.
Testing Methodology
How we conduct external penetration testing
Our external penetration testing service targets the full range of your internet-facing assets, applying both automated discovery and manual exploitation techniques.
Asset Discovery & Enumeration
We identify your public-facing assets including servers, cloud instances, exposed services, and infrastructure associated with your organisation through passive and active reconnaissance.
Vulnerability Detection & Analysis
Manual vulnerability enumeration supplemented with authenticated and unauthenticated scanning to identify outdated software, misconfigurations, and exploitable weaknesses.
Exploitation & Lateral Movement
Where vulnerabilities exist, we safely attempt exploitation in a controlled manner to validate real-world impact and assess what an attacker could achieve from initial access.
Exposed Management Interfaces
RDP, SSH, and admin panels with weak authentication are among the most commonly exploited entry points. We identify and validate these as part of every engagement.
Brute Force & Credential Testing
Where authentication services are exposed, we assess brute force protections, test for default credentials, and validate account lockout and rate limiting controls.
Configuration & Misconfiguration Review
Firewall rules, DNS configurations, TLS/SSL settings, and service banners can inadvertently expose sensitive information or provide a foothold for further exploitation.
Pricing
From £1,800
for external network penetration testing
Not sure where your network fits? A 30-minute scoping call is free and gets you a fixed written quote.
No obligation · Strictly confidential · Quote within one business day
Pricing Examples
| Small network (1-25 IPs) | £1,800 - £2,500 |
| Medium network (26-50 IPs) | £2,400 - £3,200 |
| Large network (51-100 IPs) | £3,200 - £4,000 |
| Enterprise network (100+ IPs) | £4,000+ |
What's Included
- Fixed-price proposal within one business day
- Manual, consultant-led testing. Not automated scans
- Report within 2 business days of testing completion
- Free focused retesting included to verify remediation
- No obligation quote, all enquiries are fully confidential
Indicative ranges only. Your exact price is confirmed after a short scoping conversation - see full service pricing .
Key Deliverables
What's included in the assessment?
Every external network penetration test is delivered as a defined set of outputs supporting both technical remediation and executive decision-making.
Executive Report
A non-technical summary of findings with risk ratings and recommendations suitable for board and senior management stakeholders.
Technical Report
Detailed findings with reproduction steps, severity scoring, remediation guidance, and mappings to CVE, CVSS, and MITRE ATT&CK where applicable.
Debrief Session
An offer of a debrief call to walk through findings, discuss remediation priorities, and answer questions from both technical and executive stakeholders.
Free Retesting
Complimentary focused retesting of any remediated vulnerabilities to verify that identified issues have been properly resolved.
Attack Surface Center Access
Complimentary access to our Attack Surface Center ASM platform for live finding visibility, collaborative tracking, and remediation management throughout and beyond the engagement.
Consultant-led Testing
All testing is consultant-led by in-house staff. Your consultant works with you from scoping through to debrief - nothing is outsourced or subcontracted.
Common Questions
External network penetration testing - frequently asked questions
Typical external penetration tests take 3-5 days depending on scope. Reports are delivered within 2 business days of testing completion.
If you’re preparing for your first assessment, our guide to scoping a network penetration test covers what information to have ready.
External testing is designed to safely simulate real attacks without causing service outages. We coordinate timing and agree acceptable testing windows in advance.
However, there is an element of risk for any form of penetration testing, network, or vulnerability scanning, so we will enquire as to any legacy, sensitive or business critical services during scoping to ensure that extra care is taken to minimise any potential impact.
External network testing should be performed annually at minimum. We would recommend additional testing after significant infrastructure changes, new service deployments, or following any security incidents.
Book a free 30-minute scoping call or submit a quote request online . We’ll review your external footprint, ask a few questions about scope and timeline, and provide a fixed-price proposal within one business day. There’s no obligation and all enquiries are fully confidential.
Yes, external network pentesting is a requirement for PCI DSS under section 11.4. Like internal network pentesting, coverage of the internet-facing infrastructure should be included as part of the wider assessment.
The goal of an external pentest for PCI DSS is to determine whether an unauthenticated attacker could gain access to in-scope systems or cardholder data from outside your network.
External testing focuses on internet-facing systems accessible to any attacker. Internal penetration testing assumes an attacker has already gained access to your internal network. Both are recommended as complementary assessments.
Yes, cloud-hosted infrastructure on AWS, Azure, GCP, and other platforms that form part of your external attack surface is included in our external testing scope.
Yes, we can schedule testing during agreed off-peak hours to further reduce any potential impact on your services. We will coordinate timing during the scoping phase to find a window that works best for your organisation.
No, our external penetration testing is performed remotely. We do not require any physical access to your premises or infrastructure for this service.
We do not recommend performing penetration testing during an active security incident or live attack, as this can interfere with incident response efforts and potentially exacerbate the situation. We recommend waiting until the incident is fully resolved before scheduling any testing.
Ready to test your external security?
Get a fixed-price quote within 24 hours. Our team will review your external footprint and provide a tailored scope that fits your budget and security needs.