What is vulnerability scanning? Tools & how it works

Cybercriminals are constantly looking for ways into your systems, and they're getting more sophisticated every day. In fact, over 40,000 vulnerabilities were recorded in 2024 (a 38% increase from 2023), giving attackers an ever-expanding list of potential entry points.

While you're focused on running your business, they're scanning for security weaknesses, outdated software, and misconfigurations they can exploit. The good news? You can find these vulnerabilities before they do.

Vulnerability scanning is one of the most effective ways to stay ahead of cyber threats. It's an automated process that systematically checks your systems, networks, and applications for security gaps that could put your organization at risk. 

Whether you're a small startup or a large enterprise, regular vulnerability scanning is essential for maintaining a strong security posture and protecting your business from costly data breaches.

This article shows you how to get started with vulnerability scanning, the top tools to consider, and best practices that actually work.

What is a vulnerability scan?

A vulnerability scan is an automated security assessment that identifies potential security weaknesses in your IT infrastructure. These scans use specialized software to probe your systems, networks, and applications, looking for known vulnerabilities, misconfigurations, missing security patches, and other issues that cybercriminals could exploit.

Unlike penetration testing, which involves experts simulating real-world attacks by actively exploiting vulnerabilities, vulnerability scanning is an automated process that detects potential security issues without attempting to exploit them. It’s similar to a health check for your IT environment. It identifies what’s wrong so you can address the risks, but it doesn’t show how those issues could be used in an actual attack.

How does vulnerability scanning work?

Also known as vulnerability assessment, vulnerability scanning follows a systematic process that helps organizations identify and address security weaknesses effectively. Here's how it typically works:

Step 1. Define your scan scope and goals

Before running any scans, you need to clearly define what you want to scan and why. This includes identifying which systems, networks, and applications should be included, as well as any areas that should be excluded for business or technical reasons. Setting clear goals helps ensure your scanning efforts focus on the most important assets and potential IT risks.

Step 2. Select the right vulnerability scanning tools

Choose vulnerability management tools that match your environment and security requirements. Different tools excel at different types of scans—some are better for network infrastructure, others for web applications, and some for cloud environments. Consider factors like accuracy, ease of use, reporting capabilities, and integration with your existing security tools.

Step 3. Schedule scans regularly

Decide whether to run scans continuously, on a scheduled basis, or as needed. Continuous scanning provides real-time visibility but may impact system performance. Scheduled scans (weekly, monthly, or quarterly) balance thoroughness with operational needs. Critical systems typically need more frequent scanning than less sensitive infrastructure.

Step 4. Perform network and system discovery

The scanning tool first maps your network to understand what devices, systems, and services are present. This discovery phase identifies IP addresses, open ports, running services, and basic system information. Accurate discovery is crucial because you can't protect what you don't know exists.

Step 5. Run the vulnerability scan

The tool actively probes your systems, comparing what it finds against databases of known vulnerabilities. This includes checking for missing patches, insecure configurations, weak authentication settings, and other potential security issues. The scan typically runs automatically once configured, requiring minimal human intervention.

Step 6. Analyze scan results and risk levels

Review the scan results to understand what vulnerabilities were found and how serious they are. Most tools provide risk ratings (like critical, high, medium, low) to help you understand which issues need immediate attention. This analysis phase is important for making sense of potentially hundreds or thousands of findings.

Step 7. Prioritize remediation actions

Not all vulnerabilities are equally important. Prioritize fixes based on factors like risk severity, ease of exploitation, potential business impact, and available resources. Focus on critical vulnerabilities that could cause the most damage first, then work your way down to lower-priority issues.

Step 8. Rescan to verify that vulnerabilities are fixed

After implementing fixes, run follow-up scans to confirm that vulnerabilities have been properly addressed. This verification step ensures that your remediation efforts were successful and that no new issues were introduced during the patching process.

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Benefits of regular vulnerability scanning

Regular vulnerability scanning provides numerous advantages that strengthen your overall security posture and business operations.

Identify security gaps before attackers do

The primary benefit of vulnerability scanning is finding security weaknesses before cybercriminals can exploit them. By regularly scanning your systems, you can discover and fix vulnerabilities during routine maintenance windows rather than dealing with emergency patches after an attack. 

Improve compliance with industry standards

Many regulatory frameworks and industry standards require regular vulnerability assessments. Standards such as PCI DSS, HIPAA, SOX, and ISO/IEC 27001 often mandate or recommend vulnerability scanning as part of their security controls. Conducting regular scans helps demonstrate compliance during cybersecurity audits and reduces the risk of non-compliance penalties.

Reduce risk of data breaches

Data breaches often result from unpatched vulnerabilities that attackers exploit to gain initial access to systems. By identifying and fixing these security gaps quickly, vulnerability scanning significantly reduces your risk of experiencing a costly data breach. The average cost of a data breach is about $4.9 million, making prevention far more cost-effective than dealing with the aftermath.

Strengthen incident response readiness

Regular vulnerability scanning improves your organization's overall security awareness and incident response capabilities. Teams become more familiar with potential attack vectors, common vulnerability types, and remediation procedures. This knowledge proves invaluable when responding to actual security incidents.

Build customer trust and protect brand reputation

Customers and partners increasingly expect businesses to take cybersecurity seriously. Regular vulnerability scanning demonstrates your commitment to protecting sensitive data and maintaining secure operations. This proactive approach to security can become a competitive advantage and help protect your brand reputation from security-related damage.

Save costs by fixing issues early

Addressing vulnerabilities during regular maintenance is far less expensive than dealing with the consequences of a successful attack. Early detection and remediation prevent security issues from escalating into major incidents that require emergency response, forensic investigation, legal fees, regulatory fines, and potential business disruption.

Types of vulnerability scans

Different types of vulnerability scans serve different purposes and provide varying levels of detail about your security posture:

Network-based scans

Network-based scans examine your network infrastructure, looking for vulnerabilities in routers, switches, firewalls, and other network devices. These scans identify issues like insecure protocols, unnecessary open ports, and outdated firmware.  They help you understand what entry points attackers might use to get into your network.

Host-based scans

Host-based scans look at individual computers and servers, checking their operating systems, installed programs, and settings. These scans can find missing security updates, weak configurations, unauthorized software, and compliance issues. They provide deeper visibility into endpoint security than network-based approaches.

Wireless scans

Wireless scans assess the security of your WiFi networks and wireless infrastructure. They identify issues like weak encryption, default passwords, rogue access points, and insecure wireless configurations.  With more people working remotely and using wireless devices, these scans have become increasingly important for maintaining comprehensive security coverage.

Application scans

Application scans examine web applications, mobile apps, and other software for security vulnerabilities. These scans look for common issues like SQL injection flaws, cross-site scripting vulnerabilities, authentication bypasses, and insecure data handling. Application scanning matters because many attacks target software flaws rather than network infrastructure.

Cloud-based scans

Cloud-based scans assess the security of your cloud setup, including misconfigured services, unsecured storage, excessive permissions, and compliance problems. As more organizations use cloud services, cloud-specific scanning has become essential for maintaining security across hybrid and multi-cloud environments.

Internal vs. external scans

Internal scans examine your systems from inside your network perimeter, simulating what an attacker might see after gaining initial access. External scans test your systems from outside your organization, mimicking how an external attacker would probe your defenses. Both perspectives are important for thorough security assessment.

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Top 7 vulnerability scanner tools

Various vulnerability scanning tools are available, each with different strengths and target use cases:

1. Rippling

Rippling's IT management software offers comprehensive IT security management that includes endpoint protection and threat detection capabilities through its integration with industry-leading security solutions like SentinelOne. 

The platform provides unified visibility across all employee devices, helping organizations identify and manage security vulnerabilities as part of their overall IT management strategy. Rippling's approach combines device management, user access controls, and security monitoring in a single platform, making it easier to maintain security across your entire organization.

2. Nessus

Developed by Tenable, Nessus is a vulnerability scanner that provides network, web application, database, and cloud infrastructure scanning capabilities. It offers IT vulnerability assessments, vulnerability scoring using CVSS v4, EPSS, and VPR systems, plus configuration and compliance auditing features.

3. Qualys

Qualys provides cloud-based vulnerability management through its VMDR (vulnerability management, detection & response) platform. The solution offers continuous monitoring across networks, cloud environments, and containers with risk-based prioritization using TruRisk scoring and real-time threat intelligence.

4. Rapid7 InsightVM

Rapid7 InsightVM provides vulnerability management with continuous attack surface visibility across endpoints and cloud environments. The platform uses AI-driven Active Risk scoring that integrates threat intelligence, business impact, and attacker behavior data for risk prioritization. InsightVM also offers flexible scanning options including unified endpoint agents and agentless scanning, dynamic asset discovery, and automated remediation workflows. 

5. OpenVAS

OpenVAS is an open-source vulnerability scanner that forms part of the greenbone vulnerability management (GVM) framework. Originally developed as a fork of Nessus when it became proprietary in 2005, OpenVAS provides vulnerability scanning capabilities including authenticated and unauthenticated testing across various network and industrial protocols.

6. Burp Suite

Burp Suite specializes in web application security testing with a crawling engine that includes an embedded Chromium browser to handle JavaScript-heavy applications, CSRF tokens, and stateful functionality. The platform uses out-of-band application security testing (OAST) techniques to detect vulnerabilities like asynchronous SQL injection and blind SSRF that conventional scanners miss. 

7. IBM Security QRadar

IBM QRadar is a threat detection and response solution that integrates SIEM, SOAR, and EDR capabilities for enterprise-scale security operations. The platform uses network and user behavior analytics combined with threat intelligence to provide contextualized and prioritized alerts. 

5 vulnerability scanning best practices

Following these best practices helps organizations maximize the effectiveness of their vulnerability scanning programs.

1. Run scans on a regular schedule

Establish a consistent scanning schedule that balances security needs with operational requirements. Critical systems might need weekly scanning, while less sensitive infrastructure could be scanned monthly or quarterly. In all, maintain good consistency.

2. Use both authenticated and unauthenticated scans

Authenticated scans use login credentials to access systems and check their internal configurations, finding issues that aren't typically visible from the outside. Unauthenticated scans, on the other hand, test systems without logging in, showing what external attackers would see when trying to break in. Using both types helps you understand your security from different angles.

3. Always update scanning tools and databases

Vulnerability scanners rely on constantly updated databases of known security issues. New vulnerabilities are discovered daily, so keeping your scanning tools and vulnerability databases current is essential for accurate detection. Most commercial tools update automatically, but verify that updates are being applied successfully and consider the timing of updates relative to your scanning schedule.

4. Prioritize fixes based on risk severity

Not all vulnerabilities require immediate attention. Focus your remediation efforts on the highest-risk issues first. Use vulnerability scoring systems like CVSS (common vulnerability scoring system) as a starting point, but adjust priorities based on your specific business context and threat environment.

5. Train staff on remediation workflows

Ensure your IT and security teams understand how to interpret scan results and implement fixes effectively. Provide training on vulnerability prioritization, patch management procedures, and escalation processes for critical findings. Well-trained staff can respond more quickly and effectively to vulnerability scan results, reducing the window of exposure for security issues.

Manage IT security with Rippling

Rippling helps businesses manage IT security comprehensively by combining device management, user access controls, and security monitoring in a unified platform. Instead of juggling multiple security tools and trying to correlate data across different systems, Rippling provides a single source of truth for your organization's security posture.

Rippling's integration with SentinelOne brings industry-leading endpoint protection and threat detection capabilities directly into your IT management workflow. This integration allows you to detect, investigate, and respond to security threats while maintaining full visibility into device compliance, user permissions, and access patterns across your entire organization.

Rippling's unified approach means that security vulnerabilities are addressed as part of your overall IT management strategy rather than as isolated incidents. When security issues are detected, the platform can automatically trigger remediation workflows, update device policies, and ensure that fixes are properly implemented across all affected systems.

Vulnerability scanning FAQs

How often should you run a vulnerability scan?

The frequency of vulnerability scanning depends on your organization's risk tolerance, regulatory requirements, and the criticality of your systems. Most organizations should scan critical systems weekly, important systems monthly, and less critical infrastructure quarterly. High-risk environments or those subject to strict compliance requirements might need continuous or daily scanning. The key is finding a balance between security coverage and operational impact.

Is vulnerability scanning required for compliance?

Many regulatory frameworks and industry standards require regular vulnerability scanning. PCI DSS mandates quarterly external scans and annual internal scans for organizations handling credit card data. HIPAA requires regular security risk assessments, which often include vulnerability scanning as a key component. ISO 27001 and SOC 2 also typically require vulnerability management programs. Check your specific compliance requirements to understand the scanning frequency and scope you need.

What are the limitations of vulnerability scanning?

Vulnerability scanning has several limitations that organizations should understand. Scanners can only detect known vulnerabilities in their databases, missing zero-day exploits and custom application flaws. They may produce false positives and false negatives, requiring human verification of results. Scanning can also impact system performance and may not detect all configuration issues or logical flaws. Additionally, scanners provide point-in-time snapshots rather than continuous security assessment.

What are the 5 steps of vulnerability management?

The five key steps are:

1. Identify assets and vulnerabilities

2. Prioritize risks based on impact

3. Remediate issues through patches or fixes

4. Report on progress, and

5. Monitor continuously to catch new vulnerabilities and confirm fixes.

This ongoing cycle strengthens security over time.