How to Scan a Network for Vulnerabilities

Say a burglar is trying to break into your home: the first thing they’ll look for is a weak spot where they can sneak in unnoticed. Cybercriminals use the same strategy when trying to break into your systems online. They’ll constantly test your network for vulnerabilities, and if your team doesn’t catch them first, they will.

To prevent hackers from breaking into your system, you’ll need to conduct regular network vulnerability scans and proactively address the weaknesses you find. Using a vulnerability scanner regularly will help you reduce your organization’s attack surface, stay compliant with data privacy regulations, and avoid losses stemming from data breaches or system downtime.

In this article, we’ll provide a step-by-step breakdown of how to scan your network for security vulnerabilities. We’ll also highlight different types of vulnerability scanning tools and discuss ways that professional IT support can make this process easier and more comprehensive.

Key takeaways

• Hackers often search for vulnerabilities in your system to exploit, such as misconfigured firewalls, open ports, and outdated hardware or software.
• Network vulnerability scanning tools assess your systems for possible vulnerabilities, allowing you to address them before hackers can find them.
• Raw vulnerability reports can be difficult to interpret without cybersecurity expertise. Partnering with an expert IT firm can help you get more out of your vulnerability reports.

Understanding network vulnerabilities and scanning

A network vulnerability is a flaw or weakness in your system’s configuration or design that cybercriminals could exploit to enter the system. Common vulnerabilities include outdated software, misconfigured firewalls, unpatched operating systems, open ports, or insecure protocols.

Network vulnerability scanning is the process of monitoring both hardware and software across the system to identify where potential weaknesses lie. Vulnerability scanning is an automated process that uses software to assess network servers, connected devices, and applications for abnormal activity that is associated with known vulnerabilities.

After conducting a vulnerability scan, many organizations hire ethical hackers to conduct a penetration test. In a penetration test, hackers simulate an attack on your systems and exploit the weaknesses found in a vulnerability scan to determine whether or not they exist. From there, your cybersecurity team can address the vulnerabilities to prevent an attack from happening.

Why regular vulnerability scans are essential

Don’t skip your businesses’ vulnerability scans: they could make the difference between a secure system and a data breach. Here are a few reasons why vulnerability detection is so important:

• Threats are evolving: New cybersecurity threats are discovered daily. For example, over 450,000 new malware programs are discovered each day. Hackers are constantly developing new strategies, but conducting vulnerability scans can help you stay ahead of the game.
• Upgrading your systems creates new weaknesses: When you introduce new hardware and software programs to your systems, it can create new vulnerabilities that fly under the radar.
• Configurations can drift: System misconfigurations can happen over time, often when teams make small changes as part of their daily routines. Vulnerability scanning helps you catch configuration drift before it spirals out of control.
• Scans support compliance: Some compliance standards, such as PCI DSS and HIPAA, mandate regular network scans. Failing to conduct these scans could lead to fines in the event of a data breach or external audit.

Regular scanning plays a vital role in your overall network security strategy, helping you strengthen your organization’s security posture by proactively identifying and resolving threats before they escalate.

Types of network vulnerability scans

There are several different ways you can configure your vulnerability scans, based on your network setup, IT goals, and cybersecurity concerns. Here are some of the different types of scans and how they work.

External vs. internal scans

An external scan identifies places where your system is vulnerable to an attack from outside your network. For example, these scans could identify misconfigurations in public-facing web servers, firewalls, or routers.

An internal scan identifies areas where you’re vulnerable to an internal attack. In this situation, the hacker has already gained access to your system, or a compromised insider decides to launch an attack. These scans pick up vulnerabilities in office workstations, internal servers, and other components of your internal IT infrastructure.

Both scan types are essential to protecting your systems. Many organizations focus on external attacks, but neglect the possibility of an internal threat. However, insider threats are fairly common, as 83% of organizations reported at least one insider attack in 2024.

Authenticated vs. unauthenticated scans

Authenticated and unauthenticated scans check for different types of threats, both of which are necessary to catch all the vulnerabilities present in your system.

In an unauthenticated scan, the system conducts the assessment like an outside attacker with no system credentials. This type of scan identifies vulnerabilities visible to outside attackers, such as open ports, banner grabbing, or web application flaws.

In an authenticated scan, the system scans from the perspective of an account with authentication credentials, such as an administrator. This scan reveals deeper vulnerabilities insiders might exploit. These include software flaws, missing patches, or misconfigurations.

Both types of scans help identify all possible vulnerabilities and limit security flaws.

Other specialized scans

If you’re looking for a specific type of network vulnerability, you can use a specialized scan to assess your systems. Examples of specialized network scans include:

• Web application scans: These scans for vulnerabilities within your website applications that could leave you vulnerable to things like SQL injections or cross-site scripting.
• Wireless network scans: This assesses the security of your organization’s Wi-Fi networks.
• Database scans: This scanning process cross-checks your system with vulnerability databases to identify where vulnerabilities might be present.

Step-by-step guide to conducting a network vulnerability scan

Ready to conduct a vulnerability scan at your organization? Here’s a step-by-step breakdown of the process to help you get started.

Step 1: Define the scope and objectives

Start by meeting with your cybersecurity team to determine which network segments, systems, or applications need to be scanned. Next, establish your goals for this vulnerability assessment. For example, you might choose to scan your internal network, focusing on office workstations, internal servers, and employee endpoints, to uncover threats that may not be visible from outside the organization.

From there, you’ll need to decide which type of vulnerability scan makes the most sense for your goals. For example, if you’re most concerned about internal threats, you’ll want to conduct an authenticated vulnerability scan.

Step 2: Choose your vulnerability scanner

Next, you’ll need to decide which network vulnerability scanner you want to use. There are two categories of tools to choose from: open-source tools and commercial tools.

Open-source tools, such as OpenVAS and Nmap, are free to use. Nmap is particularly helpful for port scanning. However, your team will need significant technical expertise to operate the scan and interpret the results.

You can also opt for commercial tools, such as Nessus, Qualys, or Rapid7. These tools come with a cost, but they also tend to be more powerful than open-source tools and provide more comprehensive results. They’re also more likely to integrate with other security tools you’re using. 

Many commercial tools also provide API integrations, allowing you to connect your scanner with ticketing systems, security dashboards, or automated remediation workflows.

Another solution is cloud-based vulnerability scanners, which are easy to deploy and maintain. These tools don’t require on-premise installation and are ideal for distributed teams or hybrid environments.

When selecting a scanning tool, you’ll need to compare factors like cost, functionality, integrations, and reporting capabilities to determine what makes the most sense for your organization.

Step 3: Prepare your network and systems

Once you’ve chosen a tool, you’ll need to prepare your network and systems for the scan. Choose a date and time when the scan won’t be disruptive to your operations. Inform your IT staff of the scan ahead of time, as they can sometimes trigger false cybersecurity alerts.

Start by ensuring you have adequate bandwidth and system resources, and then connect the scanner to your network. If you’re conducting an authenticated scan, you’ll need to give the scanner temporary credentials for it to run properly.

Step 4: Configure and run the scan

Next, set up the configurations for your scan. Select your IP addresses or ranges, and set appropriate scan policies in the system based on your goals. Set the date and time for the scan based on what’s most realistic for your organization.

Step 5: Analyze and prioritize results

This is the most critical step in the vulnerability scanning process. When the scan is complete, the tool generates a detailed report with raw vulnerability data. This will include a list of common vulnerabilities and exposures, or CVEs.

Start by scanning the list for false positives. Automated tools sometimes flag items that aren’t actual vulnerabilities, so you’ll need to have an expert assess the list and remove anything that isn’t putting your system at risk.

Then, use an in-depth risk scoring method like the CVSS to identify how dangerous each vulnerability is. Risk scoring will help you determine which security weaknesses to address first during remediation. In general, you’ll want to prioritize weaknesses that are highly severe, easy for hackers to exploit, could affect critical systems or sensitive data, and are internet-facing.

Step 6: Remediate and re-scan

After the analysis is complete, take steps to resolve the highest-priority vulnerabilities first and then work your way down to less urgent risks. You may need to reconfigure systems, apply patches, or close open ports during remediation, among many other things.

Once you’ve remediated all vulnerabilities, run another scan to confirm that all issues have been successfully addressed. Many teams often overlook this key step in vulnerability management.

Step 7: Documentation and continuous improvement

After each vulnerability scan, document the entire process from start to finish, including what you found, the steps you took to fix issues, and what you learned for future scans. Documentation helps streamline your internal operations, and it can also help you prepare for future compliance audits.

Put together a regular scanning schedule to ensure you’re continuously finding and eliminating security risks in your system. Depending on your security needs, you could schedule scans monthly, quarterly, or after major changes to your systems.

Limitations of vulnerability scanning

Vulnerability scanning is an essential component of risk mitigation, but it does have some limitations. It’s important to pair vulnerability scanning with other security strategies to prevent cyberattacks.

Here are some of the possible limitations of vulnerability scanning:

• Only identifies known vulnerabilities: Since scanning tools rely on existing vulnerability data, they can’t catch zero-day vulnerabilities in real time.
• High false positive rate: To avoid false positives, vulnerability reports should be read and interpreted by cybersecurity analysts who can weed out false alarms.
• Doesn’t prove exploitability: Just because a vulnerability is present does not mean that a hacker has the capabilities to exploit it. Pen testing helps determine whether a vulnerability is exploitable.
• Requires interpretation: Vulnerability reports are difficult to read and act on without cybersecurity knowledge. Security teams will need access to experts to conduct remediation.
• Cannot substitute human expertise: Vulnerability scans and other forms of security automation should not be your only line of defense. They should be paired with the expertise of security analysts or incident response experts.

Why professional network vulnerability scanning with Diamond IT is essential

Performing basic vulnerability scans is a great first step toward keeping your network safe. However, ongoing vulnerability management is a complex process requiring expertise that many organizations do not have in-house.

This is where a managed IT services provider like Diamond IT can help. Diamond IT is a team of certified cybersecurity professionals who provide third-party support for technical tasks like vulnerability scanning.

With Diamond IT’s expert guidance, you can conduct more comprehensive vulnerability scans and use them to build a stronger cybersecurity strategy. Our team will help you configure your scans, analyze the results, navigate remediation, and document the entire process for compliance.

Diamond IT helps your team handle these complex and time-consuming cybersecurity tasks, so your team can spend time on internal operations. In addition to vulnerability scanning, we can also assist with things like 24/7 network and endpoint monitoring, software updates, employee cybersecurity training, and more.

Get in touch with our team today for a free cybersecurity assessment and to learn more about our services.