What is vulnerability scanning and how does it work?

Every modern business that connects to the internet relies on multiple workstations and handles sensitive business and customer information that needs careful protection against malicious actors. While various cyber practices can help achieve system security, vulnerability scanning is an automated and efficient way to spot system security weaknesses before hackers can exploit them. Learn more about how vulnerability scanners work and how to use them to protect your organization.

What is vulnerability scanning?

Vulnerability scanning is an automated process for identifying security weaknesses in systems, networks, applications, or devices. It helps organizations address flaws that attackers could exploit. As a critical step in cybersecurity risk management, vulnerability scanning is now typically fully computerized, using tools that flag vulnerabilities and report them to the security team.

How does vulnerability scanning work?

With dozens or even hundreds of computers, laptops, IoT devices, mobile devices, databases, and applications, modern company networks are just too crowded for manual vulnerability scans. Instead, risk teams use an automated vulnerability scanning process to run regular scans to detect and address network weaknesses.

1. Preparation. The vulnerability scanning process begins with setting the scope for the scan and deciding which IP ranges, systems, and applications to include and how often to run it. For example, critical assets are usually scanned weekly, while less crucial ones get monthly or annual check-ups. Once that's set, the scanner does a thorough inventory of all the organization's IT assets, from active devices and services to applications and open ports in the target environment.
2. Scanning and analysis. After collecting data on devices and programs, the scanner analyzes system configurations, software versions, and network settings and compares them to a database of known vulnerabilities. This process helps identify potential weaknesses that attackers could exploit. Next, the tool compiles a report, ranking flaws by severity, likelihood of exploitation, and potential impact.
3. Remediation. Once the vulnerability report is complete, the next step is to address the identified issues. After applying fixes, it's important to rescan and monitor the system to make sure the vulnerabilities have been properly patched and everything stays secure.

Understanding the core purpose of vulnerability scans

The core purpose of vulnerability scanning is to spot weak points in system, network, and application security before cybercriminals find them and use them for their own profit. These scans are a crucial step in a vulnerability management process that security teams use to catch security flaws in the network's architecture. It's an efficient mechanism that finds missing patches, misconfigurations, weak passwords, open ports, outdated software, and vulnerable applications.

Frequent and thorough vulnerability scans aren't just about security — they also help meet industry standards like FedRAMP, GDPR, PCI DSS, and ISO 27001. By identifying vulnerabilities before attackers exploit them, you keep systems secure and ensure compliance with industry requirements. For example, the Payment Card Industry Data Security Standard (PCI DSS) mandates quarterly scans for companies handling cardholder data, while FedRAMP requires regular scanning to protect federal information. In short, regular vulnerability scans could be your company's way of showing customers and regulators that data security is your top priority.

What are the types of vulnerability scanning?

Let's see how different types of vulnerability scanning can help you enhance your security posture.

External scanning

External vulnerability scanning involves identifying flaws in your organization's infrastructure exposed to the internet. It gives the security team in-depth information about misconfigurations in the network's ports or web applications. However, this type of vulnerability scanner might not be the best option for continuous monitoring because it performs a comprehensive network analysis that requires a lot of system resources, consumes bandwidth, and slows performance.

NordStellar's external vulnerability scanner could be a good addition to your vulnerability management program. It's designed to identify system vulnerabilities before they lead to data breaches. It continuously monitors ports, detects outdated software, finds faulty APIs, and identifies misconfigurations and other security flaws in their early stages. This gives you more time to respond to emerging risks and prevent potential threats.

Internal scanning

Internal scanning checks your network devices, routers, switches, servers, and other systems behind the company's firewall. It looks for outdated software, misconfigurations, and anything that could be exploited by malware or compromised insiders. These scans help detect weaknesses that external scans might miss.

Port scanning

Port scanning checks for open ports on a system. It sends data packets to specific ports and analyzes port responses and statuses. The results help security teams diagnose network issues and identify weaknesses. While businesses use port scanning to spot exposed ports, hackers can do the same to find flaws to exploit. That's why it's important to scan ports for vulnerabilities before they do — to get ahead of potential threats.

Cloud vulnerability scanning for AWS, Azure, and GCP

Businesses that rely on cloud platforms must make sure that the environment is secure for storing sensitive corporate data. Whether you use AWS, Azure, GCP, or any other cloud, scanning for critical vulnerabilities will help you assess your security posture and detect security flaws.

Remember that keeping your sensitive data away from prying eyes isn't just on them — monitoring for potential weaknesses is a shared responsibility. So, if you use a hosted service for computing resources, run regular vulnerability scans to maintain cyber resilience against online threats.

Container vulnerability scanning

Container orchestration systems like Kubernetes or Docker are on the rise because they keep all the network applications and programs running, organized, and ready to use without requiring on-premise infrastructure. However, as container-based software use gains popularity, its security becomes a key part of the developer's responsibility.

Just like any other software, containers might have vulnerabilities that hackers may exploit if not managed carefully. That's why container vulnerability scanning is essential. These scans analyze key components — the base image, code, and dependencies — to identify potential security risks so your IT team can fix them.

Web application vulnerability scanning

Web application vulnerability scanning helps find critical flaws in your infrastructure's apps, such as productivity, finance, and marketing optimization tools, communications platforms, or HR management systems. It is crucial to mitigate those potential threats before cybercriminals can exploit them and steal sensitive data.

Regular web application scanning identifies security loopholes and simulates attacks on your networks. It then provides a thorough report describing those weaknesses, determining severity levels, and giving recommendations on how to fix those issues.

Host-based vulnerability scanning

Host-based vulnerability scanning focuses on a network's hosts (individual devices or computers). Instead of scanning your whole network for weaknesses, it checks a specific system or device for vulnerabilities in the operating system, software, file systems, and user accounts and privileges.

Database vulnerability scanning

The purpose of database vulnerability scanning is to check databases for security weaknesses and get a full and comprehensive picture of their security posture. Regular database scans are crucial because they usually store the organization's most valuable and sensitive information, such as customer data, financial records, or intellectual property. Any unattended attack vectors could allow malicious actors to gain unauthorized access and steal this information, which could cost the organization business disruptions, reputation, or hefty sums of money.

Like other types of vulnerability scanners, database scanning tools analyze each discovered vulnerability, such as misconfigurations or lack of encryption, and provide the risk team with a thorough report on how to mitigate those weaknesses.

Choosing the right vulnerability scanning tools

There's no one-size-fits-all solution when choosing a vulnerability scanning tool — it depends on various factors, like your organization's size, IT infrastructure, and how well the tool integrates with existing security systems. However, an ideal vulnerability scanning tool should offer:

• Accuracy. An effective scanner should accurately identify vulnerabilities while keeping false positives and negatives to a minimum. The provider should also maintain an up-to-date vulnerability database and leverage machine learning to enhance detection accuracy over time.
• Coverage. Your network vulnerability scanning tool should identify flaws across various IT assets, including networks, endpoints, web applications, databases, cloud environments, virtual systems, and IoT devices. It should detect known security flaws, zero-day vulnerabilities, and system misconfigurations that malicious actors could exploit.
• Integration. Integrating a network scanning tool with existing security tools shouldn't be a hassle. Before purchasing, make sure your chosen service provider has key integration features compatible with your antivirus software, firewalls, intrusion detection systems, privileged access management, and application security systems.
• Cost. The cost of a scanning tool varies based on deployment models, licensing, and scalability needs. Pricing options may include per-asset, per-scan, or enterprise subscriptions. Cloud-based scanners typically follow a subscription model, while on-premise tools often require a one-time fee.
• Compliance support. If your business operates in a regulated industry, choose a vulnerability scanner that can help you meet compliance requirements for GDPR, HIPAA, and PCI DSS by identifying security gaps. Some tools also generate audit-ready reports and offer real-time monitoring to catch issues.

Implementing a vulnerability scanning program in your organization

Aligning an effective vulnerability scanning program with your company's security goals may be challenging but possible. First, you'll need to determine which systems and data are the most critical so you know what needs the most protection. Next, pick a scanning tool that fits your setup (it can be cloud-based or on-premise).

Once you've picked the right tool, integrate it with your existing cybersecurity tools and set up vulnerability scanning frequency (or configure continuous scanning). Finally, prepare a solid plan for fixing system weaknesses and train your employees on how to read vulnerability data. And don't forget to keep your vulnerability database updated to stay ahead of future threats.

Vulnerabilities detected: What to do?

So, your vulnerability scanner has flagged an issue. Next, you'll need to prioritize threats, apply patch management, and remediate the system. Here's how:

• Prioritize risks. Not all vulnerabilities are equally dangerous. Assess their severity, exploitability, potential impact, and affected assets. Address weaknesses that could lead to data breaches or system compromises first.
• Mitigate the issue. Then, patch vulnerabilities for which you already have fixes. If you don't have a patch for the issue, look for temporary workarounds — turn off affected features or tighten firewall rules — until you find one.
• Test before deploying. Test patches in a controlled environment before applying them. Make sure they don't cause downtime or compatibility issues with existing patches and features.
• Monitor. Once you fix the detected flaws, keep an eye on your systems to make sure the patches are effective.

FAQ

How does vulnerability scanning differ from penetration testing?

The difference between vulnerability scanning and penetration testing is that vulnerability scanning detects security weaknesses, while penetration testing simulates real cyberattacks to test system defenses. Vulnerability scanning uses automated tools to spot outdated software, misconfigurations, or weak credentials, while penetration testing involves ethical hackers trying to exploit vulnerabilities to see how far an attacker could get within the system.

How does vulnerability scanning differ from antivirus software?

Vulnerability scanners and antivirus software are both cybersecurity tools, but their purposes are different. A vulnerability scanner assesses weaknesses in systems, networks, and applications, while antivirus software is designed to detect and remove malware.

How does vulnerability scanning work in CI/CD pipelines?

Vulnerability scanning is a crucial step in CI/CD pipelines used for software development. It does automated security checks during the development process. First, it checks the code for common issues and third-party libraries for known security issues. If you're using containers, it checks their images for vulnerabilities, too. Then, it scans the software's infrastructure for misconfigurations. After the program is done, it simulates cyberattacks on the running application in a staging environment to check for weak spots.

If the scanner detects any vulnerabilities, it will instantly alert you that something's off and offer tips on fixing these issues.