Penetration testing vs. Vulnerability Scanning

Keeping your business secure is a constant battle against cyber threats. That’s where penetration testing and vulnerability scanning come in – two powerful tactics to identify weaknesses before attackers exploit them. But there are key differences between them. Penetration testing is a thorough manual assessment to find security weaknesses, while vulnerability scanning is an automated test that sweeps your systems for potential holes. Let’s compare these techniques, exploring their unique strengths, and limitations, and how using them together can improve your organisation’s security strategy.

What is penetration testing?

Penetration testing, or pen testing, employs ethical hacking techniques to purposely attempt to break into your systems and networks, simulating real-world cyber attacks. This proactive approach rigorously tests your security controls across various areas, providing critical insights into the true security of your network and systems. There are various types of penetration testing from network and web app pen testing, to mobile, social and physical penetration tests. It identifies vulnerabilities before malicious hackers can exploit them, enabling you to prioritise remediation efforts and ensure the effectiveness of your security measures. 

Penetration testing activity looks at vulnerability to assess real-world risks, whereas vulnerability scanning identifies potential weaknesses through broad visibility. Combined, they’re complementary practices to enable comprehensive cyber security assessments and strategies.

What are the advantages of penetration testing?

The main advantage of penetration testing is its ability to simulate real-world attacks to identify vulnerabilities before exploitation. By validating the effectiveness of security controls, organisations can mitigate risks, prioritise remediation efforts, and realise cost savings from preventing breaches. This robust assessment provides invaluable insights into an organisation’s true security posture. Here, we explore each of the benefits in more detail. 

Identifying vulnerabilities

Penetration testing meticulously explores existing security measures and uncovers vulnerabilities that attackers could exploit. This process allows businesses to identify weak points within their systems and infrastructure, helping to make informed decisions about exactly where to bolster defences. This tailored approach pinpoints the areas that need controls, like patching and strengthening making sure those specific vulnerabilities are addressed with appropriate security solutions.

Risk mitigation

Penetration testing provides vital insights that contribute to stronger defensive strategies. By simulating attacks, organisations can evaluate their incident response capabilities and fine-tune their security protocols, significantly lowering the chances of a successful breach. This strategic risk management is crucial in maintaining integrity and trust in business systems. Ultimately, penetration testing enables organisations to reduce their overall risk exposure and enhance their resilience against cyber threats.

Cost savings

Penetration testing reduces security budget requirements in several ways. It minimises the need for costly automated scanners prone to false positives, and the detailed reports also train developers on vulnerabilities, reducing future costs. Thorough testing decreases the likelihood of costly bug bounty discoveries, and identifying vulnerabilities early in development can drastically lower remediation expenses compared to fixing issues post-deployment. Finally, it lowers the risk of breaches and associated reactive costs like incident response and potential regulatory fines. By proactively securing systems, penetration testing provides a cost-effective approach to cyber risk management.

What are the limitations of penetration testing?

Penetration testing does have a few limitations to consider, including providing only a snapshot in time, opening up the potential for missed vulnerabilities or false positives, the inability to fully simulate real-world attacks, and the reliance on the skill and experience of the tester. It may also pose risks of system disruption or data exposure. Here, we explore some of the disadvantages of penetration testing you should be aware of.

Time and resource intensive

Penetration testing is a labour-intensive process that requires significant investment in time and resources. It involves detailed planning, execution, and follow-up to be effective. Each test must be precisely aligned with the environment and requires skilled personnel to conduct, making it a potentially resource-intensive security exercise. Exploring options for IT support inclusive of penetration testing from a trusted provider like Cheeky Munkey could be a consideration to ensure limited disruption to the day-to-day operations of your team.

Skill dependency

The success of penetration testing hinges significantly on the expertise of the ethical hackers performing the test. These professionals must be highly skilled in a variety of attack methods and up to date on the latest security trends. The effectiveness of penetration testing heavily relies on the tester’s ability to identify vulnerabilities, devise creative attack tactics, and accurately assess the potential impact of exploits. Less experienced or skilled testers may overlook critical vulnerabilities or fail to uncover complex attack paths, leading to an incomplete assessment. Finding and retaining such talent can be challenging and costly, especially for smaller companies or those in less tech-focused markets, making external professional partnerships the best option for many.

Legal and ethical concerns

Penetration testing raises significant legal and ethical concerns requiring careful management. Penetration testing essentially involves intentionally attempting to breach systems – actions that could potentially cause harm if not properly authorised and controlled. Explicit permission must be obtained from all relevant stakeholders before testing. Even with approval, clear rules of engagement defining the specific scope are crucial to avoid compromising critical operations or data.

There’s also ethical implications around certain tactics like social engineering that should be weighed against the organisation’s standards. Penetration testing providers must have rigorous compliance processes ensuring all activities are conducted within legal and ethical boundaries. Failing to properly navigate this could expose the business to lawsuits, penalties, and reputational damage.

Maximising security benefits requires deliberately managing the complex legal and ethical concerns around penetration testing. Proper due diligence means vulnerabilities can be identified while avoiding costly mistakes.

What is vulnerability scanning?

Vulnerability scanning is an automated scan designed to assess the security of computer systems, networks, or applications by identifying known vulnerabilities. Also known as vulnerability assessments, this process is typically automated, using software to scan and analyse a system for potential security threats without human intervention. It provides an initial overview of potential exploitable areas. They can be initiated manually or scheduled to run periodically and can last from several minutes to several hours.

Vulnerability scans are a passive approach to vulnerability management because they only report detected vulnerabilities. It’s the responsibility of the business owner or IT support to prioritise and address identified weaknesses, either by patching them or confirming and addressing false positives, and then re-running the scan. Ideally, vulnerability scans should be conducted by a PCI Approved Scanning Vendor (ASV).

What are the advantages of vulnerability scanning?

There are many positive reasons to use vulnerability scanning as a proactive security measure. Regular scans provide continuous monitoring, allowing timely patching and remediation. Vulnerability scans can be an affordable option to cover networks, systems, and applications, ensuring comprehensive protection as they are often automated. This can improve efficiency, reduce human error and facilitate compliance with security standards. Below, we delve into some of those benefits in more detail. 

Early threat detection

Vulnerability scanners quickly and efficiently identify security weaknesses, alerting businesses to potential threats at an early stage. This early detection allows for rapid response, significantly reducing the window of opportunity for attackers to exploit these vulnerabilities. By integrating scanning into the software development lifecycle, vulnerabilities can be caught early before applications are deployed to production environments. Timely patching and virtual patching can then reinforce these applications against emerging threats. Regular scanning also ensures that newly discovered vulnerabilities are quickly identified and mitigated.

Continuous monitoring

Automated vulnerability scanning provides ongoing surveillance of systems, continually monitoring for new vulnerabilities as they emerge. This persistent vigilance helps ensure that security measures are always up-to-date and effective, providing a crucial layer of ongoing protection in the dynamic landscape of cyber threats. By automating this monitoring process, businesses can achieve consistent coverage without the resource constraints of manual efforts. Vulnerability scanning provides a proactive security posture, detecting exposures before attackers can identify and exploit them. This real-time awareness means rapid risk mitigation and it strengthens overall cyber resilience.


Because vulnerability scanning is automated, it requires fewer human resources, making it a more affordable option for continuous security monitoring. This cost efficiency makes it accessible to a wider range of businesses, including small and medium-sized enterprises that might not have the budget for intensive manual testing processes like penetration testing.

What are the limitations of vulnerability scanning?

Automated vulnerability scans aren’t risk-free; poorly planned ones can disrupt operations like real-world attacks. Scoping such projects often uncovers mission-critical processes running off-hours that can’t be interrupted. However, frequently scanning across all your systems and assets is important for verifying that your actual risk exposure aligns with how much risk your organisation is willing to accept. It allows you to get ahead of vulnerabilities before they can be exploited, rather than just reacting after issues arise. Below, we look at some of the other key limitations of vulnerability scanning to keep in mind.

False positives

A common issue with vulnerability scanning is false positives. This is where the system incorrectly identifies a legitimate activity or software as a threat. This can lead to wasted resources and time as teams investigate and address these non-issues. Over time, this constant noise of false alerts can lead to desensitisation, potentially causing real, genuine threats to be overlooked or deprioritised. False positives erode confidence in the scanning system and undermine its effectiveness as a security control. Careful tuning and testing of scan configurations is needed to reduce excessive false positive rates while maintaining comprehensive coverage.

Limited scope

While vulnerability scanners excel at finding known, common vulnerabilities, they struggle when it comes to detecting new or complex security weaknesses that require more context and analysis. These automated tools lack the nuanced perspective and creative thinking that experienced human analysts can provide. As a result, some novel vulnerabilities or intricate attack methods may fly under the radar of scanners until they are actively exploited by hackers. Relying solely on automated scanning tools means potentially missing vulnerabilities that require more lateral thinking and contextual understanding to uncover. Having skilled people examine systems from an attacker’s perspective complements and reinforces the automated scanning process.

Network Visibility

Vulnerability scanning faces challenges in environments like remote or cloud-based systems, where network visibility can be limited. These platforms can mask vulnerabilities from scanners, making it difficult to detect and address weaknesses effectively. This limitation is particularly concerning in modern IT environments, where remote and cloud services are increasingly common.

For strong cyber security, combining penetration testing and vulnerability scanning is powerful. Penetration testing uses experts to actively hack your systems while scanning tools automatically check for known vulnerabilities. Together, these techniques let you thoroughly assess exposure from multiple angles. This comprehensive view means you can prioritise the biggest risks and allocate resources efficiently. However, both methods have limitations, so infrastructure, resources, and specific needs should help you decide the best way forward.

Ultimately, the decision to utilise penetration testing, vulnerability scanning, or a combination of both should be driven by a holistic risk management strategy. Gain more insights on penetration testing for small businesses here, and discover the range of professional IT support Cheeky Munkey offers, including penetration testing to safeguard your business. 

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