Vulnerability Scanning vs. Penetration Testing: Which Do You Need?

Penetration testing and vulnerability scanning are two very different services, a common misconception is that they are the same, this cannot be further from the truth. This article will help your business understand how to best utilise both services to improve your network and application security. 

What is a Penetration Test? 

A penetration test is an effective method of simulating a cyber attack on your organization in the hopes of identifying vulnerabilities that can be exploited by malicious actors. These penetration testers are commonly referred to as ethical hackers, they perform reconnaissance where they carry out a lot of hands-on research on your organization in the hopes of formulating an attack strategy. They then through the manipulation of current vulnerabilities gain and maintain access to your organization's systems as an actual hacker would do. The result of a penetration test is an extremely detailed report on how your system can fix its vulnerabilities and strengthen its defences against cyber attacks. 

Benefits vs. Limitations of a Penetration Test

What is a Vulnerability Assessment?

A vulnerability assessment, also commonly referred to as a vulnerability scan, also assesses your network and computer systems for vulnerabilities. These scans are automated and give you an initial idea of which vulnerabilities in your system can be exploited by hackers.

Vulnerability scans that are of a high quality can search for more than 50,000 vulnerabilities and are common procedures under cyber security frameworks like PCI DSS. These vulnerability scans can be started manually or run as per a schedule and can take several minutes to several hours to complete. Vulnerability scans are considered to be a passive method to managing vulnerabilities as it simply reports the ones that are detected, with a chance of vulnerabilities being false positives. A false positive is a threat that is identified by the scan that is not real. It is the organization’s responsibility to figure out how to patch and prioritise the vulnerabilities after eliminating the false positives in the report. 

Benefits vs. Limitations of a Vulnerability Scan

So what is the difference between the benefits of a Penetration Test versus a Vulnerability Scan? 

The easiest way to explain the difference between these assessments is through the following analogy from the medical world. Imagine you are suffering from pain in your lower body and you visit a doctor to diagnose your problem. He or she may start by recommending a CT scan, which involves taking a combination of X-ray scans taken at different angles to produce a series of images. If that information isn’t sufficient the doctor may recommend an MRI, MRIs provide more detailed information about the inner organs (soft tissues) such as the brain, skeletal system, reproductive system, and other organ systems than is provided by a CT scan. Even though conducting an MRI may take longer, more effort, and cost more than a regular CT scan, it is required if you want to identify why you are suffering. These differences are similar to the differences between Penetration Tests (Detailed MRIs) and Vulnerability Scans (Initial CT Scans). 

Another difference between Penetration Tests and Vulnerability Scans is the human element. Penetration tests are conducted by humans whereas vulnerability scans are conducted by machines. 

There is no such thing as an automated penetration test. The best penetration testers are highly experienced and technically well versed in but not limited to the following: 

1. Adversary Simulation (e.g., remote access attacks, SQL injection)
2. Internal and external testing (i.e., perspective of someone within the network, perspective of hacker over Internet)
3. Web front-end technologies (e.g.,Javascript, HTML)
4. Web application programming languages (e.g., Python, PHP)
5. Web APIs (e.g., restful, SOAP)
6. Network technologies (e.g, firewalls, switches, IDS)
7. Networking protocols (e.g., TCP/UDP, SSL)
8. Operating systems (e.g., Linux, Windows)
9. Scripting languages (e.g., Python, Perl)
10. Testing tools (e.g., Nessus, Metasploit)

So which assessment should your organization pick? 

Similar to the situation where your doctor recommends both an MRI and CT scan when diagnosing an illness, the simple answer is both. To ensure the highest standard of information security it is important for your organization to conduct timely vulnerability assessments as well as enlist the help of a penetration tester to strengthen your defences against rapidly evolving cyber threats.

Although both processes are beneficial on their own, it’s best to use them both in tandem. This is known as vulnerability assessment and penetration testing (VAPT).

VAPT is ideal because it will provide your organisation with a more detailed, comprehensive evaluation than would be possible with a single test on its own. Not only are you scanning for weaknesses for potential threats, you’re also performing an authorised attack to identify real issues.

As a result, your testing is more robust, which helps better protect your company from the full scope of cyber attacks. Any advantage you can have in this day and age, the better.