Vulnerability Assessment vs Penetration Testing

business consulting at laptop
Image credit: Jack Sparrow

Cybersecurity isn’t a one-time, set-it-and-forget-it process. Instead, organizations that want to proactively eliminate cyber threats need diligent assessment and testing procedures to ensure their defenses are up to date.  

When it comes to assessing and/or testing the security posture of a network to determine the existence of weaknesses in defenses, prudent organizations will work towards maturing the processes that help in this manner. For many, this means developing and deploying more sophisticated time-tested approaches: vulnerability assessments and penetration tests.  

While vulnerability assessments, a type of cyber risk assessment, and penetration testing are similar, they each can help organizations make different discoveries about where threats lie and how to bolster security.  


First, let’s begin with definitions – 


Vulnerability Assessment: “A vulnerability assessment is the process of defining, identifying, classifying and prioritizing vulnerabilities in computer systems, applications, and network infrastructures.” (Rosencrance, 2021) 


Penetration Test: “A penetration test, also called a pen test or ethical hacking, is a cybersecurity technique organizations use to identify, test and highlight vulnerabilities in their security posture.” (Contributor & Mehta, 2021) 


For the purposes of this article, the purview of penetration testing is considered a traditional manual (hands-on) approach. 

Purpose of Vulnerability Assessments vs Penetration Testing

In the simplest terms, vulnerability assessments are designed to show where weaknesses are whereas penetration tests are designed to show how well defenses hold up.  

Purpose of a Vulnerability Assessment

New vulnerabilities are found every day. Vendors like software providers do their best to quickly generate, update and push scanning signatures out to their client base to help organizations in their remediation efforts. This really is a continual process, an ongoing process of security maintenance. Prudent organizations will run scans on a reoccurring basis to determine the current state of their security posture according to the latest signatures. 

If vulnerability assessments are characterized as security maintenance, then the intent is to scan all in-scope assets in attempts to uncover and discover as many weaknesses as possible and provide solutions with the goal of remediation. 

Purpose of a Penetration Test

Penetration Test: Organizations will either use their in-house staff or hire third-party consultants to emulate methods and approaches of attackers for the sake of testing strengths and weaknesses in existing systems. Here the consultant will look to leverage findings, by gaining footholds into the network and exploiting these weaknesses to establish persistence and compromise evaluated assets. Loosely translated, they will verify if you have a rabbit hole, and illustrate to you how far and wide it goes. 

Penetration testing will attempt to leverage one or more identified weaknesses with the end objective of determining the degree of success an attacker might have in gaining unauthorized access to organizational assets. This is much more of a focused test and may not include the testing of every asset. 

Timing: Penetration Testing vs Vulnerability Assessment

Penetration testing takes more time than vulnerability assessments. Assessment results from a vulnerability assessment can be available within hours or days as compared to penetration testing, which may take days, weeks or longer to complete. 

Which Takes Longer: Vulnerability Assessment or Penetration Testing?

Many organizations and leaders wonder when the right time is to schedule a vulnerability assessment or a penetration test.   

Deciding factors might be based on regulatory requirements which may outline the rate and scope of testing. Another factor could be changes in infrastructure. Modification of networks (technology, applications, software, and size) all translate into differences in an organization’s attack surface. Organizational change introduces the potential for new or missed vulnerabilities which need to be addressed for true cybersecurity. 

Another reason leaders may choose to run a penetration test or vulnerability assessment might be related to a security incident. For example, if an organization is breached, it will need to determine how attackers were able to get in and work to remediate the findings. Additionally, forensic work, a form of breach response may be part of this evaluation.

How often should a business conduct a vulnerability assessment or penetration test?

Many organizations will adopt a timeline where vulnerability assessments are performed on a monthly or quarterly basis and then have a penetration test performed on a semi-annual or annual basis.  

The usage cadence between the two will vary based upon business requirements and purpose. Organizations at greater risk, or those with more stringent compliance requirements may choose a more aggressive testing and assessment schedule.

Differences in Evaluating Cyber Risk

Vulnerability assessments and penetration testing use different methods to assess the threat posed to an organization.  

Vulnerability Assessment

Vulnerability assessments are often conducted with automated scanning technology. This then means that there is the potential for false positives. These automated results are then reviewed by a live expert who can help to interpret the data and remove the noise. While not a full-fledged manual test, the assessment aspect of this approach will include some level of validation to help reduce the number of false positives. This arguably gives clients better actionable results. 

Another issue with machine-led testing, (surface level findings), is that the identified weaknesses will also have risk ratings assigned by the scanning platform. These ratings, while designed to prioritize risk for clients so they can address the more critical findings first, may not be an accurate representation of the existing security landscape.

Penetration Testing

Manual penetration testing incorporates the human aspect (discernment) in not only evaluating the risk rating of the identified vulnerability, but the likelihood of exploitation. Here, the risk rating may be increased or decreased based upon the success or failure of the consultant to exploit the findings from the automated (scanning portion) of the testing workflow. 

Why you need both penetration test and vulnerability assessments

Some industry numbers state only a small percentage of security vulnerabilities are identified from scanning alone. By using a combination of the two approaches, vulnerability assessments and penetration testing, organizations will have a more accurate and encompassing view of their security posture. Gaining more insight into the security risk in your organization will manifest in more educated decisions, further enhancing the overall organizational security culture. 


Looking for expert guidance in securing your organization against cyber threats and security breaches? Foresite Cybersecurity offers an array of cybersecurity and compliance maturity solutions for organizations of all sizes. Get a demo of ProVision Open XDR to find out more about the 24/7 cybersecurity coverage offered by ProVision or request a demo of Foresite Integrated Risk Management (FIRM) to see a real-time risk score based on your technology, policy, and practices. 

Dana Morrow
Director of Security Services at Foresite Cybersecurity | + posts

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