Difference Between Vulnerability Assessment & Penetration Testing

Published on : 01 Sep 2020


While many professionals claim to be aware of the Vulnerability Assessment and Penetration test, they often misinterpret both the terms and use them interchangeably. Vulnerability Assessment and Penetration testing are two different terms but form an integral part of the cyber security management programs. People fail to understand the differences and with this misconception miss out on vital components in their overall network security profile. To set the records clear, both are different vulnerability assessment processes that cannot be replaced by one another or cannot be used as a standalone process to secure the entire network.  Both are important at their respective levels and essential for cyber security and risk analysis. They are two different processes combined (VAPT analysis test) to achieve optimum network security. These are processes required by various information security standards like PCI PIN, PCI DSS, HIPAA, SOC2, ISO 27001 to name a few, for organizations to secure the environment and to be compliant to various information security standards.

In today’s post, we intend to clear the common misconception and highlight the differences between Vulnerability Assessment and Penetration Testing. The article details when and where each of the security assessment processes is used and applicable to organizations. However, before we move on to learn the differences, let us first understand both terms.

Also Read : Types Of Penetration Test

What is Vulnerability Assessment?

Vulnerability Assessment is a technique or process that helps identify security vulnerabilities in a given environment or network. The assessment helps determine the level of susceptibility to different vulnerabilities the system is exposed to. It is a comprehensive assessment process that involves using automated security scanning tools to find and measure the severity and level of exposure to vulnerabilities in an environment. Tools like NESSUS, Rapid Nexpose,  Web-scan, CISCO Secure Scanner, SQL Diet, etc. are used for analyzing the network/application and yielding a list of vulnerabilities that are prioritized (low, medium, high) based on its severity. The findings of the assessment are typically analyzed and escalated to the security and operational team with appropriate remediation to mitigate or reduce the potential risk. The Assessments is an in-depth evaluation of an organization’s network or system security posture that uncovers weak areas.

What is a Penetration test?

Completely in contrast to Vulnerability Assessment, the Penetration Test which is also known as the Pen Test is a practice of testing systems/networks to determine security vulnerabilities in a system by ethically hacking into it. The practice involves attempting an exploit by simulating a real-life attack in the form of ethical hacking into systems to test the defense and determine weak areas.  The test identifies potential paths an attacker could route through into the systems and orchestrate an attack and breach defense systems. Similar to Vulnerability Assessment, Penetration testing also involves using automated Vulnerability tools and scanners to determine vulnerabilities. However, in addition to the automated tools, other manual Pen test tools are utilized to scan and test web applications and network infrastructure.

Also Read : Automated to Manual Approach To VAPT

Key differences between Vulnerability Assessment & Penetration test

Titles Vulnerability Assessment Penetration Test
  MeaningVulnerability Assessment is the process of identifying known vulnerabilities in a system and determine potential exposure or weak areas in a system.  Penetration Test is a practice that involves exploiting the weak areas in a system to determine the degree to which an attacker can penetrate into a system and gain unauthorized access to business-critical data.  
Purpose The assessment is conducted to identify known vulnerabilities that could compromise a system and expose business-critical assets to a security breach.The test conducted aims to identify unknown threats and weak areas in a system and determine the level of risk the systems are exposed to.
Network & Application  The Assessment is conducted on networks and applications internally from within the organization.The tests are generally conducted remotely, on external networks and applications to identify weak areas and potential threats.
Coverage Vulnerability assessmentis more inward and focused on identifying all security weaknesses in a system and strengthen the defense mechanism from within the system and network. It could possibly be a regular practice in an organization to consistently maintain a secure network status.    Penetration Testing is more outward and focused on identifying weak areas in a system externally. It is a test conducted externally to identify the level of exposure to unknown threats.   
Applicability The Assessment is ideally suitable for organizations that are believed to be not secured and wish to identify known security issues. It is an assessment typically meant to identify all the possible security weaknesses within their systems. Typically organisations do a VA of the entire central resources and even a sample of the endpoints on a regular basis.  The test is suitable for organizations that assert strong security defense but wish to check if their systems are hackable or exposed potential attack or breach. It is a technique of testing an organization’s established defense systems, especially when they are believed to be strong. Typically organisations conduct penetration tests only of their critical infrastructure: servers, databases and firewalls  
Process The Vulnerability Assessment process involves- Discovering assets within the environment.Identify vulnerabilities across networks and applications. Prioritizing and ranking risk levels from low, medium to high levels.Delivering reports highlighting pain areas and suggesting remediation. Remediation of vulnerabilities by configuring system changes, patch management,  and hardening of security infrastructureThe Penetration Testing process involves- Determine the scope of test and level of exploitation on identifying vulnerabilities. Identifying vulnerabilities and ranking the severity of risk associated. Simulating a real-life attack and exploiting identified vulnerabilities. Inject agents to maintain access to the system, till the time identified. Conduct a risk analysis of to learn about the level/ depth of access achieved into the system. Delivering reports highlighting the identified risks, ranking the severity of risks, and suggesting remediation for the same.Implementing suggested remediation and fixing loopholes in the security systems.Conducting a re-test to ensure the implementation of suggested remediation and ensure strengthening of defense.  
Approach The assessment conducted is programmed and involves using various toolsThe test conducted is intuitive and involves the utilization of tools and manual processes.
Automated/manual The Vulnerability Assessment is an automated process wherein tools like web security scanners and network security scanners are used for identifying vulnerabilitiesThe Penetration Test involves using both automated tools and adopting a manual process for identifying and exploiting vulnerabilities.
Outcome of the assessment/test The assessment identifies or rather uncovers several known vulnerabilities that can compromise a system and expose it to a potential attack.The test helps identify weak areas that are unknown and provide a solution for preventing a potential attack. 
Reports The report includes a comprehensive list of identified vulnerabilities in the system that are maybe exploitable. It may also include false positives. The report also consists of suggested remediation for building strong defense systems.The report includes a list of comprehensive vulnerabilities that were exploitable and the severity of risks ranked from low, medium to high. The report also consists of remediation for fixing the lapse or loopholes in the defense systems.
Nature of the Assessment/ TestThe Vulnerability assessment conducted is passive by nature and does not involve the exploitation of identified threats.The Penetration Test conducted is aggressive by nature for it involves the exploitation of identified vulnerabilities by conducting an ethical hack into the system.
Detective/preventive measures It is are more of a detective control which simply involves identifying and fixing vulnerabilities.It is more objective and involves identifying, exploiting, and implementing preventive measures.  
Duration of the test The duration for Vulnerability Assessment ranges from minutes to a few hoursThe duration for Penetration tests ranges from days to a few weeks.
When to performVulnerability Assessment is most often scheduled and conducted at regular intervals, especially when their changes are introduced in the systems/network/controls.A penetration test can be conducted annually or when significant changes are introduced in the system/network/controls. 
Who can perform the assessment/testThe test can be conducted by in house technicians using authentic credentials and relevant tools for detecting known threats from internal network and application. Organizations can even hire a third-party vendor to manually assess, identify, review, and confirm the results.  The test needs to be conducted by an experienced and qualified penetration testing service providers. They are generally qualified white-hat hackers or ethical hackers having the skills to hack into systems and networks and identify weak areas or security setting lapse in a system from an external network or application.
Cost factor Vulnerability Assessments are comparatively less expensive than a Pen Test wherein the expenses range from low to moderate. The penetration test requires hiring highly skilled and knowledgeable personnel which may naturally be expensive. 

Is Vulnerability Assessment & Penetration Testing related?

Now that we have learnt about the key differences between Vulnerability Assessment & Penetration Testing, let us move on to understand whether or not Vulnerability Assessment and Penetration Testing are related to each other. Although the two practices are very different, however, both combined form an essential part Network Security Assessment Management Program. So, coming back to the question of whether the two practices are related? Well, yes they are related to each other.

In Summary: The Penetration Testing process to a great extent depends on the Vulnerability Assessment.  So, to initiate the Penetration Testing process, it requires a complete vulnerability assessment scan to be done, to determine any vulnerabilities present in the system.  Once the vulnerabilities are identified, the tester further moves on to exploit them. With vulnerability Assessment, a tester can only get to know the possible vulnerabilities and leave them unexploited up to this point. It is Penetration testing that then confirms the extent to which the vulnerabilities Identified can be exploited.

So, Penetration testing goes a step further, exploiting the vulnerabilities by entering deep into the network/systems and assess the level to which the tester can enter a system and access critical information. Ultimately it is both the test combined that ensures optimum network security of an entire IT Infrastructure. Penetration testing and Vulnerability Assessment together also popularly known as VAPT Assessment helps organizations in their Compliance efforts. It is currently the most essential practice for an organization’s wanting to achieve compliance with standards like the PCI DSS, GDPR, ISO 27001 to name a few.

The below-given diagram is a visual representation of how Vulnerability Assessment & Penetration Tests are relative


Penetration Test or Vulnerability Assessment? Which one is suitable for your organization?

Having understood the difference and relevance between the Vulnerability Assessment & Penetration Test, now the question arises as to which one is suitable for your organization? Well, the objective of Vulnerability Assessment is to identify weak areas of your system/network and fix them. On the other hand, the objective of Penetration testing is to exploit the identified vulnerabilities and assess the level of depth to which one can break into the system and access critical information. So, depending on whether the organization wants to find the known vulnerabilities within their system and build strong security frameworks or simply test the strength of their existing defense mechanism can opt for a Vulnerability Assessment or a Pen Test for their Organization’s IT Infrastructure.

Vulnerability Assessment and Penetration Test helps highlight the pain areas and fix to secure networks and systems. The overall aim of VAPT is to improve the overall security of systems and strengthen an organization’s security stance. An organization needs to choose between the two tests, depending on the organization’s compliance objective, functionality, and business criticality. However, it is important to note that if you go for a Pen test, then it definitely covers vulnerability Assessment as well.


Vulnerability Assessment and Penetration Test are both equally essential from an information security and cyber security risk analysis standpoint. The VAPT test can help determine relevant controls, security systems, and frameworks that are required and best suits your business practice. Both the tests together work as an excellent strategy to reduce cyber security risk. However, to implement relevant tests or assessments, it is very important to know the difference, significance, purposes, and outcome of each test. Lack of knowledge and training in context to both the test could pose a greater security risk. Organizations should consult with industry experts to analyze and understand which assessment or test works for them to strengthen the organization’s security posture.

Narendra Sahoo
Narendra Sahoo

Narendra Sahoo (PCI QPA, PCI QSA, PCI SSF ASSESSOR, CISSP, CISA, CRISC, 27001 LA) is the Founder and Director of VISTA InfoSec, a global Information Security Consulting firm, based in the US, Singapore & India. Mr. Sahoo holds more than 25 years of experience in the IT Industry, with expertise in Information Risk Consulting, Assessment, & Compliance services. VISTA InfoSec specializes in Information Security audit, consulting and certification services which include GDPR, HIPAA, CCPA, NESA, MAS-TRM, PCI DSS Compliance & Audit, PCI PIN, SOC2 Compliance & Audit, PDPA, PDPB to name a few. The company has for years (since 2004) worked with organizations across the globe to address the Regulatory and Information Security challenges in their industry. VISTA InfoSec has been instrumental in helping top multinational companies achieve compliance and secure their IT infrastructure.