Penetration Testing vs Vulnerability Assessment

There seems to be a certain amount of confusion within the security industry about the difference between Penetration Testing and Vulnerability Assessment, they are often classified as the same thing when in fact they are not.

Penetration Testing may sound a lot more exciting, but most people actually want a VA not a pentest, many projects are labelled as pen tests when in fact they are 100% VA.

A Penetration Test mainly consists of a VA, but it goes one step further..

A penetration test is a method of evaluating the security of a computer system or network by simulating an attack by a malicious hacker. The process involves an active analysis of the system for any weaknesses, technical flaws or vulnerabilities. This analysis is carried out from the position of a potential attacker, and can involve active exploitation of security vulnerabilities. Any security issues that are found will be presented to the system owner together with an assessment of their impact and often with a proposal for mitigation or a technical solution.

A vulnerability assesment is what most companies generally do, as the systems they are testing are live production systems and can't afford to be disrupted by active exploits which might crash the system.

Vulnerability assessment is the process of identifying and quantifying vulnerabilities in a system. The system being studied could be a physical facility like a nuclear power plant, a computer system, or a larger system (for example the communications infrastructure or water infrastructure of a region).


Vulnerability assessment has many things in common with risk assessment. Assessments are typically performed according to the following steps:

1. Cataloging assets and capabilities (resources) in a system

2. Assigning quantifiable value and importance to the resources

3. Identifying the vulnerabilities or potential threats to each resource

4. Mitigating or eliminating the most serious vulnerabilities for the most valuable resources


This is generally what a security company is contracted to do, from a technical perspective, not to actually penetrate the systems, but to assess and document the possible vulnerabilities and recommend mitigation measures and improvements.

On the other hand, a pen test simulates the actions of an external and/or internal attacker that aims to breach the security of the organization. Using many tools and techniques, the penetration tester attempts to exploit critical systems and gain access to sensitive data. Depending on the scope, a pen test can expand beyond the network to include social engineering attacks or physical security tests. Also, there are two primary types of pen tests: "white box", which uses vulnerability assessment and other pre-disclosed information, and "black box", which is performed with very little knowledge of the target systems and it is left to the tester to perform their own reconnaissance. Typically, pen tests follow these steps:

1. Determination of scope
2. Targeted information gathering or reconnaissance
3. Exploit attempts for access and escalation
4. Sensitive data collection testing
5. Clean up and final reporting

by Andriy Skop