Penetration Testing

Penetration Testing, or a Pen Test, is a security test that launches a mock cyber attack to find vulnerabilities in a computer system.

A pen test is a way to identify vulnerabilities before attackers do, evaluate how effectively you can respond to security threats, assess your compliance with security policies, and improve the level of security awareness amongst your staff.

Penetration testers are security specialists trained in ethical hacking, using hacking methods and tools to identify and fix vulnerabilities rather than exploit them maliciously. Organisations purchase pen testing services to carry out simulated attacks on their applications, networks, and other systems. These controlled attacks enable security teams to discover serious weaknesses and strengthen their overall security defences.

While “ethical hacking” and “penetration testing” are sometimes used interchangeably, there is a subtle distinction. Ethical hacking is a broader discipline within cyber security that encompasses any application of hacking expertise to bolster security. Penetration testing, or pen testing, is one specific approach within ethical hacking, focusing on attack simulations. Ethical hackers may also offer malware analysis, risk evaluations, and other security-enhancing services.

Penetration Testing

A Penetration Test aims to exploit the vulnerabilities of an organisation’s cybersecurity arrangements before a malicious party does. It uses a combination of automatic and manual techniques to identify issues within the infrastructure, systems and operations.

Vulnerability Assessment

Vulnerability Assessments are most often used by organisations when they want to identify the vulnerabilities present in their infrastructure and to get a high-level overview of their security posture. It involves an external approach and is fully automated.

Vulnerability Assessments are useful for companies who do not have visibility or understanding of their security posture. A vulnerability assessment can often be used as the first stage of a larger penetration testing project.

For organisations with legacy infrastructure, it is a quick, cost-effective way to identify and focus on software versions and systems that can be fixed easily.

External Penetration Test

An external penetration test replicates a real-life attack, searching for vulnerabilities that can be exploited by a hacker. This type of analysis aims to target everything Internet-facing. The penetration tester will focus on identifying network vulnerabilities. This can include issues with network services and hosts, devices, web, mail and FTP servers.

Objective Examples: Obtaining internal access to the network

Internal Penetration Test

An internal penetration test aims to identify and exploit internal vulnerabilities. Vulnerabilities can range from misconfigurations through to unpatched software and social engineering. The approach would be similar to an external penetration test, and the process followed would be the same.

Often the aim of this test can be unique to each client. A customer’s objective could be to gain access to a sensitive file or the domain controller with full admin rights, to elevate privileges or to perform an overall security assessment.

This type of test is only possible with access to the internal network either provided by the customer or gained by dropping a device like a dropbox or Raspberry PI onto any open network port, or by exploiting a compromised system i.e. emails.

Objective Examples: Leveraging internal access to obtain access to important assets on the network

Web Application Penetration Test

The web application penetration test aims to find weaknesses in applications programmed in-house or out of the box solutions, as well as ill-coded websites.

Web Apps are often vulnerable to many types of attacks that are often possible through the exploitation of misconfigurations in server builds or through bad coding practices. Vulnerabilities are often identified within functions where user input is received, like website search, address fields, file uploads, where SQL queries can be passed to gain access to back end databases. If either of those functionalists are not appropriately secured an attacker could exploit them to upload a malicious document that can create a back door giving a user unauthorised access to the underlying server it is running on.

Due to the world wide web being publicly exposed many websites and online stores come under constant attack. Identifying these vulnerabilities before anyone else can allows remediation actions to take place to secure the web app.

Examples: Brute-force attack, Error handling, SQL Injection and XSS.

Social Engineering

Social engineering is manipulating people into leaking sensitive information and providing an external malicious agent with unwarranted access to a network or building. It exploits the gaps in cyber security education in organisations and employs psychological persuasion.

The pen tester will research different aspects of the company and its people, refer to social media and current events, to gain the trust of the host and blend in with the organisation. However, social engineering is not limited to physical infiltration, but can also involve the use of email, social media and calls.

Performing such a test can reveal the gaps in cybersecurity awareness of the organisation’s people and stress the importance of employee training.

Examples: Phishing campaigns, traditional scamming techniques such as authority figure impersonation.

Red Team Engagement

A red team engagement is the more advanced version of a penetration test appropriate for companies with mature, well-established security arrangements. Compared to a pen test, they tend to take longer and often require multiple testers. The main objective is not to find and exploit all vulnerabilities, but instead, it is a targeted attack with a single objective aiming to be completely unnoticeable. Such tests are performed in scenarios where there is an immediate Blue team (Response Team) to stop a Red team (Attackers) in their tracks.

Black-Box Testing

In black-box testing, a tester doesn’t have any information about the internal working of the software system. It is a high-level assessment that focuses on the behaviour of the software. It involves testing from an external or end-user perspective. Black-box testing can be applied to virtually every level of software testing: unit, integration, system, and acceptance.

White-Box Testing

White-box testing is a testing technique which checks the internal functioning of the system. In this method, testing is based on coverage of code statements, branches, paths or conditions. White-box testing is considered as low-level testing. The white-box testing method assumes that the path of the logic in a unit or program is known.

CyberLab explains how Vulnerability Assessments (VAs) and Penetration Tests (Pen Tests) work, how they complement each other, and how to build a sensible testing cadence that fits risk and change.

• Vulnerability Assessment: Automated discovery of known weaknesses across systems and networks, producing a prioritised list to remediate. Fast coverage, broad visibility, highly repeatable.
• Penetration Test: Expert‑led simulation that chains weaknesses to achieve realistic attack objectives, validating impact and controls. Deeper insight, business‑level risk narrative, targeted improvements.

Both are essential. A VA finds what is exposed. A Pen Test proves what is exploitable and why it matters.

A Vulnerability Assessment actively scans internal and/or external infrastructure to identify known weaknesses that attackers could exploit. It is run against defined IP ranges or assets and produces a report with findings and remediation guidance.

Typical issues uncovered include:

• Unpatched or end‑of‑life software
• Misconfigured or exposed services and ports
• Default or weak credentials (for example, admin/admin)
• Insecure protocols and ciphers (for example, legacy TLS versions)

Where it helps most:

• As the first step in a security testing journey, establishing a baseline quickly
• As a regular control to catch drift from secure baselines, configuration errors and newly disclosed vulnerabilities

Cadence: Monthly or quarterly is common, depending on change rate and risk appetite. Remember that VAs, like Pen Tests, provide a point‑in‑time view, so frequency matters.

Beyond automation: While scanning is largely automated, experienced teams add value with context, open‑source intelligence (OSINT) where appropriate, and aftercare that helps teams interpret, prioritise and fix efficiently.

A Penetration Test goes further and deeper. It uses expert techniques to validate how vulnerabilities can be combined, exploited and escalated to achieve meaningful objectives.

Activities typically include:

• Research and reconnaissance
• Threat modelling and attack path analysis
• Vulnerability exploitation and privilege escalation
• Lateral movement and data access validation (within agreed scope)
• Documentation of impact with an executive summary, attack narrative, and ranked remediation plan

Cadence: Often annual as a baseline, with additional testing after significant changes such as new remote access solutions, major application releases or compliance drivers. Pen Tests are more resource‑intensive and take longer than VAs, which is why a staged approach is effective.

Think of a network as a house.

• A Vulnerability Assessment identifies weaknesses: a rusty lock, a half‑open window, a bin that could be used as a step.
• A Penetration Test tries to chain these findings: test the lock, leverage the bin to reach the window, and prove whether a break‑in is possible.

Both insights are valuable. The VA shows where to improve. The Pen Test shows what really happens if issues are left unfixed.

• Depth vs breadth: VA prioritises coverage and speed, Pen Test prioritises depth and realism.
• Automation vs expertise: VA is largely automated with expert interpretation, Pen Test is expert‑led throughout.
• Outcome: VA provides a list of weaknesses to remediate, Pen Test provides validated attack paths, business impact and targeted fixes.
• Frequency: VA more frequent to reduce exposure between changes, Pen Test periodic or change‑driven to validate resilience.

1. Start with a VA to remove the obvious and reduce the attack surface quickly.
2. Follow with a Pen Test to validate critical paths, controls and detection/response.
3. Repeat VAs regularly to catch configuration drift and new vulnerabilities.
4. Trigger Pen Tests after major change or on a set cycle to keep assurance current.

Vulnerability Assessment report:

• Clear asset scope and scan coverage
• Findings grouped and prioritised by severity, with fix guidance
• Trends over time when assessments are run regularly

Penetration Test report:

• Executive summary in business terms
• Attack narrative that explains how access was achieved and what it enabled
• Ranked vulnerabilities with technical detail and remediation steps
• Evidence that supports replication and verification

Both are only worthwhile if the organisation acts on remediation and tracks closure.

• High change or internet‑facing assets: VA monthly, or more frequently for critical services
• Broad internal estate: VA quarterly
• Pen Test: annually as a baseline, plus after significant architectural or application change, or when required by regulation

Plan windows carefully. Automated scans can be “noisy” on the network, and some Pen Test activities may require coordination to avoid operational disruption.

Look for independent, accredited testing delivered under strict NDAs and with clear separation from sales and implementation teams. Frameworks such as CREST help ensure quality, ethical practice and consistent methodology. Vendor‑agnostic reporting and unbiased recommendations support better decision‑making.

CyberLab helps organisations plan a sensible testing programme, starting with rapid visibility through a Vulnerability Assessment and moving to targeted Pen Testing that validates real‑world risk. The team can also support prioritised remediation and help embed repeatable processes so improvements stick.

To discuss scope, cadence and outcomes that fit your environment and risk profile, the CyberLab team is available for an initial consultation.