Vulnerability Assessments: A Comprehensive Guide

What is a Vulnerability Assessment?

A vulnerability assessment aims to identify weaknesses in a digital system so they can be reported and remediated. These vulnerability assessments can be carried out manually by highly-trained pentesters (cyber security experts/ethical hackers) or automated scanners.

Once these weaknesses are identified, they will be scored using the CVSS or Common Vulnerability Scoring System to grade each vulnerability based on severity. This enables organisations to take calculated action by managing risk and prioritising the high-severity vulnerabilities first.

Why are Vulnerability Assessments Important?

Since vulnerability assessments identify weaknesses in a digital system, they are fundamental in helping organisations manage risk by patching vulnerabilities.

If organisations were unaware of these vulnerabilities, they would be at a higher risk of being exploited by hackers. This can be highly damaging to an organisation’s reputation, lead to loss of personal data, and, in severe scenarios, lead to its permanent closure.

What are the Different Types of Vulnerability Assessments?

While the purpose of vulnerability assessments does not change, i.e., discovering and reporting vulnerabilities, the type of vulnerability assessment can change based on the target. Here are the most common types of vulnerability assessment.

Network-based Scans

As the name suggests, network-based vulnerability scans are designed to identify vulnerabilities in network devices such as firewalls, routers, and other network infrastructure components that a hacker could exploit.

Tools and techniques commonly used for network-based scans include port scanning, which scans a network for open ports; network mapping, which identifies and maps devices on a network; and vulnerability scanning, which scans network devices for known vulnerabilities, missing patches, and misconfigurations.

Host-based Scans

Host-based scans are designed to identify vulnerabilities in host systems. They examine the software, configurations, and system settings of laptops, servers, mobile devices, etc.

Commonly used techniques include patch management and vulnerability scanning, which involves scanning the host for missing patches and known vulnerabilities in an operating system (OS); file integrity monitoring or FIM, which consists of monitoring critical system files for unauthorised changes that could indicate a security breach or malware infection; and, log analysis to detect any unusual or suspicious log activity.

Click to learn more about why outdated operating systems are dangerous, and seven ways to protect your business against ransomware attacks.

Wireless Network Scans

Wireless network vulnerability assessments focus on identifying vulnerabilities within wireless networks, such as Wi-Fi. They also identify rogue access points, weak encryption, and other common vulnerabilities.

Commonly used techniques include passive scanning, which involves listening to wireless traffic without actively transmitting packets; active scanning, which involves probing the wireless network and monitoring responses; and packet sniffing, which captures and analyses packets transmitted over the wireless network.

Application Scans

Application vulnerability assessments involve scanning software applications, such as websites, APIs, and mobile applications, for vulnerabilities. They are often conducted using checklists like the OWASP Top Ten, a list of the most common application vulnerabilities.

Want to learn more about the OWASP Top Ten? Check out our comprehensive guide.

Database Scans

Database vulnerability assessments involve scanning digital databases, such as servers, for vulnerabilities, misconfigurations, and rogue/corrupted databases. They can also ensure that no one, including employees, can gain unauthorised access to classified/confidential information.

Vulnerability Assessments vs. Penetration Testing

Vulnerability assessments scan for weaknesses, and penetration testing takes it further by attempting to exploit them. Most of the confusion surrounding the two comes from the fact that pentesting requires the pentester to conduct a vulnerability assessment to find the weaknesses they wish to exploit.

Penetration testing is arguably more valuable than vulnerability assessments since they are more thorough and provide the organisation with a comprehensive understanding of their system vulnerabilities and how they can be exploited. As discussed earlier, vulnerability assessments only identify the weaknesses and report them; however, penetration tests are more expensive, so it is common for companies to use vulnerability assessments more frequently than pentests.

To learn more about penetration tests, check out our comprehensive guide.

What are the Stages of Vulnerability Assessment?

Similar to penetration testing, vulnerability assessments have five key stages – preparation, scanning, analysis, reporting and remediation. Each stage is vital for conducting a safe and effective vulnerability assessment.

Preparation

In this stage, an organisation will define the scope of the assessment by determining the systems, networks and or applications that will be assessed. Once the scope has been defined, the pentesting service provider will begin planning what tools and techniques they will use to identify vulnerabilities in the target environment.

Scanning

In the scanning phase, the pentester will use automated scanning tools, including network scanners like Nmap and vulnerability scanners like Nessus, to identify vulnerabilities within the target environment.

Analysis

Once they have completed the scanning phase, they will assess and analyse the results they have found so they can accurately report their findings to the client. They will also likely rerun some tests to ensure the results are accurate.

Reporting

In this phase, the pentester will prepare a highly detailed report outlining the vulnerabilities they found and the potential impact of those findings using the Common Vulnerability Scoring System (CVSS) and deliver this report to the client.

Remediation

In the final stage, the client will act on the penetration tester’s remediation recommendations to the best of their ability, prioritising the high-risk areas first. Once the client has done this, they will conduct another vulnerability scan to double-check that the issues have been addressed.

What Tools and Techniques are Used in Vulnerability Assessments?

Similar to penetration testing, the tools and techniques used in a vulnerability assessment depend significantly on the type of pentest being carried out and the target. Each tool has its strengths and weaknesses, and different companies will use different tools for various reasons, including usability, cost and effectiveness.

That said, here are some very commonly used tools.

Nmap – Network Scanning

“Nmap, also known as Network Mapper, is a highly effective and adaptable network scanning tool. With Nmap, users can effortlessly discover hosts and services on a computer network, detect operating systems, identify open ports, and collect information about different network devices.”

There are 65,535 possible ports on an IP address, and checking all of them manually takes a very long time. So, companies often use active scanning tools, such as Nmap, to find open ports before cataloguing them depending on what sort of traffic they receive and transmit and what versions they are running, i.e., whether they’re up-to-date.

Nessus Expert – Vulnerability Scanning

“Nessus Expert is an effective tool to help you discover vulnerabilities across your attack surface. It supports scanning across a variety of asset types such as operating systems (MacOS, Windows, Linux), applications, network devices and more.”

Like Nmap, tools like Nessus can scan entire networks or work in tandem with tools like Nmap to monitor specific ports. Using its database of known vulnerabilities, it can highlight vulnerabilities within the network.

Other vulnerability scanners commonly used by pentesting companies include Qualys and Nexpose.

Automated Tools

An automated tool is a software application that automatically scans systems, networks and applications to identify vulnerabilities, including open ports, outdated software, misconfigurations and missing patches. These tools streamline and speed up the vulnerability assessment process by performing scans that would take a pentester hours to complete manually.

Manual Tools & Techniques

Security professionals use manual tools and techniques in vulnerability assessments to test and identify vulnerabilities that automated tools might miss. They can also delve deeper into vulnerabilities highlighted by automated tests.

Check out our guide if you want to learn more about the differences and similariities between manual and automated pentests.

What are the Benefits of Vulnerability Assessments?

The benefits of regular vulnerability assessments are fairly straightforward and there are far too many to name all of them. So, here are the three most common benefits.

Improved Security

The entire purpose of carrying out a vulnerability assessment is to improve your digital security by highlighting vulnerabilities and fixing them. Regular vulnerability assessments can ensure that your employees, clients, sensitive data, etc., are kept safe.

Risk Management & Trust

Few things ruin a brand’s reputation, quite like major data leaks. Regular vulnerability assessments significantly reduce the risk of such events and are, therefore, a fantastic means of maintaining a high level of trust with your employees, customers, and investors.

Compliance

While it is likely that a full penetration test is required at least annually for many compliance regulations, vulnerability assessments are still a fantastic way to ensure that your organisation remains compliant and adheres to industry best practices.

Plus, they can help you avoid costly fines – compliance is cheaper than non-compliance.

Common Misconceptions of Vulnerability Assessments?

There are several common misconceptions surrounding vulnerability assessments that often stem from a lack of understanding of what vulnerability assessments actually are. Hopefully, this article has helped with a lot of that. Just in case anything was missed, here are three common misconceptions of vulnerability assessments.

One-Time Fix

A single vulnerability assessment does not ensure long-term cybersecurity. It might seem salesy that a pentest service provider is telling you that you have to purchase multiple vulnerability assessments, but we assure you, we’re saying this for your benefit.

Technology is constantly advancing, and as it advances, cybercriminals’ ability to identify and exploit vulnerabilities in technology is also advancing. This means that regular vulnerability assessments are vital for ensuring long-term cybersecurity.

Only Automated

Vulnerability assessments are not exclusively carried out by automated tools, and that is a good thing. While we have covered this already, it’s important to stress that the best vulnerability assessments are carried out manually by expertly trained ethical hackers who use automated tools alongside their own knowledge and techniques.

Automated tools lack the ability to understand the context of a situation. Not all vulnerabilities are obvious, and automated tools rarely acknowledge these subtleties. This is why having a trained pentester manually carry out these tests using automated tools is the best way to ensure the best results.

Only for Large Organisations (Expensive)

This is a very dangerous misunderstanding because it puts small and medium-sized businesses at risk of exploitation. It is vital that businesses of all sizes conduct regular vulnerability assessments.

Tying in with the misconception that vulnerability assessments are very expensive, there are plenty of cost-effective methods out there. While these cost-effective methods will not be as thorough as standard vulnerability assessments, some protection is better than none. At the end of the day, a successful cyberattack can not only ruin your reputation but also your business.

Conclusion

Vulnerability assessments aim to identify vulnerabilities in a digital system so that they can be reported and remediated. They should be carried out as often as possible and annually as a minimum.

Automated scanners are great, but without context, they can often miss major vulnerabilities, and manual pentests would not.

Finally, vulnerability assessments should be carried out by all companies. While they can be expensive, cyberattacks can cause irreparable damage and are, therefore, significantly more costly.