Toggle menu


What is CNI penetration testing?

Critical National Infrastructure (CNI) is vital to national wellbeing, ensuring that essential services continue to operate at all times. Under the NIS Regulations, CNI operators have a legal duty to make sure that IT systems are fully protected in the event of a cyberattack, and that they have plans in place to respond effectively to an incident.

CNI penetration testing puts people, processes and technology under scrutiny. Using the same tools and techniques as hackers, CHECK-certified consultants will attempt to breach network defences to expose vulnerabilities that require urgent attention.

Why does CNI penetration testing matter?


Penetration testing is essential

Identifying and resolving network vulnerabilities is crucial to protecting CNI resources. It is only when these systems are put to the test that security issues are uncovered.


To achieve compliance

CNI operators are bound by the NIS Regulations – but they must also comply with GDPR and various PSN CoCo agreements. Failure to comply could result in significant fines or loss of access to critical infrastructure services.


Audit preparations

CNI operators are subject to routine security audits. Conducting penetration testing allows you to identify and resolve issues before the audit, reducing the risk of failing compliance testing.


Validation of incidence response planning

As cyberattacks increase in frequency, your incidence response plans will be called into action – and soon. Penetration testing allows you to safely assess plan effectiveness, and fine-tune processes before they are needed.

Our Approach

Penetration testing

CHECK qualified engineers ‘attack’ your firewall and network assets to identify vulnerabilities that may be exploited by hackers. Using the same tools and techniques they do, we will help you understand the strengths and weakness of your security technologies.

Physical security testing

Cybercriminals may gain access to your network by first visiting one of your sites. Fidus engineers will test the systems and processes that control physical access to your sites and ensure that access control safeguards are being properly applied.

Phishing and social engineering tests

People will always be the weak point in your security systems. Fidus engineers conduct social engineering attacks to assess how well your staff respond and where additional training is required.

Red Team scenarios

Conducting a full-scale Red Team cyberattack on CNI network systems allows you to assess how people, processes and technology really work together in an emergency.

Talk to us about your CNI requirements today

Get in Touch

Why Fidus?

Penetration testing reveals your most sensitive network vulnerabilities – so you need a partner you can trust. Fidus Information Security are an NCSC CHECK Green Light and TIGER scheme approved consultancy. Our cyber security experts hold some of the most recognised certifications in the industry, including CREST Certified Tester and Senior Security Tester. Fidus is also a Cyber Essentials verified company. Every assessment we perform is carried out according to UK industry approved methodologies (OWASP, PETS, NIST) along with our own internal testing frameworks.

Remedial Support

More than just identifying security vulnerabilities, our cyber security experts are on hand to help you fix them too.

Certified Security Consultants

Our CREST and TIGER approved team holds a range of industry-leading security certifications including OSCP, CCT, SST and CISSP

Easy to Understand Reports

We’ll ensure that your executives and technical teams properly understand our assessment findings using plain-English reporting.

Fixed Price Proposals

The price you’re quoted is the price you’ll pay. Our quotes are broken down into a detailed costing table so you know exactly what to expect.

The Industry Average

Other approaches we've witnessed have included convoluted steps and commonly ends with incorrect information being handed to the consultant assigned to the engagement.

The Fidus Way

Our approach to security involves a qualified security consultant through the entire process to ensure quality, accuracy and consistency.

Trusted by

Get in Touch with Fidus Information Security

From the Blog

All Articles
Research 22 March 2021
Silently Unmasking Virgin Media VPN Users in Seconds (CVE-2019-16651)

Introduction Fidus’ R&D team identified a vulnerability within Virgin Media Super Hub 3 routers that permitted for exfiltration of sensitive information remotely, which, among other things, can be used to determine the actual, ISP issued IP address of VPN users. A vulnerability we were asked to hold back from releasing for a whole year. A […]

Research 20 March 2020
XSSLash – A Tale of Playing Quiplash at Work

Introduction Quiplash – a game full of wit, banter and borderline acceptable humour… and security consultants on a lunch break. To set the scene, the date was 19th February 2020 and the mood was cheerful in the Fidus office. Lunch had just been delivered and today was the day that Mario Kart was not going […]

Request a Call Back

Would you like to speak to us over the phone? Just submit your details and we’ll be in touch shortly. You can also email us if you would prefer – [email protected]

I would like to discuss:

    All fields are required

    “Oysta is very happy with the support, service and dedication of the Fidus team. Working with the Oysta team every step of the way, not only did they check all security on the device, they also provided feedback on the quality of the hardware. I will be working with Fidus again.”

    Mario Zuccaro, Founder and CEO, Oysta Technology

    June 2019

    “We have been really pleased with the service provided by Fidus. We have found them to be extremely easy to work with. We also felt their fee structure was reasonable. We would recommend Fidus to anyone looking for a PCI pen testing partner.”

    Andy Phillips, Inspired Outsourcing

    May 2019

    “Great service. Gave us exactly what we needed, as promised.”

    Philip Cunnington, TalkPlus NHS

    January 2019

    “We were extremely pleased with the service, knowledge and professionalism shown by Fidus. After the remediation phase, we then ran a phishing exercise with them to remind staff of the need to be vigilant with external email communications. I would have no hesitation in using or recommending Fidus in the future due to the quality of work carried out at a great price.”

    Graeme Thistlethwaite, ICT, Business Change and Business Support Manager

    “Fidus provided a high quality penetration service at a reasonable price … communications were great … the Pen test team flexed around us and our other commitments to get the job done. Thanks!”

    Darren Crombie, CEO, Upstream Outcomes

    October 2018