How to Run a Vulnerability Scan on Your Network
A practical, five-step guide to finding security gaps before attackers do, interpreting the results, and building a remediation plan that sticks.
Every device on your network is a potential entry point. Printers, switches, firewalls, workstations, and servers all run software, and software has flaws. A vulnerability scan is the fastest way to catalog those flaws, rank them by severity, and give your team a clear list of what to fix first.
Yet many SMBs put off scanning because the process seems intimidating or expensive. The truth is that modern tools have made vulnerability scanning accessible to organizations of every size. Below, we walk through the five steps to go from zero to a prioritized remediation plan, whether you handle it in-house or bring in a partner like Bullium Consulting.
Understand What a Vulnerability Scan Actually Does
A vulnerability scan is an automated process that probes every reachable host on your network, identifies the software and services running on each one, and cross-references what it finds against databases of known security flaws (CVEs). The output is a report that lists each vulnerability, its severity rating, and guidance on how to fix it. It is not the same as a penetration test. A pen test uses manual techniques to actively exploit weaknesses; a vulnerability scan identifies them without attempting exploitation, making it safer to run during business hours.
Think of it like a building inspection versus a break-in simulation. The inspector checks every lock, window, and alarm system and hands you a punch list. That is the scan. The red-team exercise where someone actually tries to pick the locks comes later, informed by what the scan uncovered.
The Bullium Fix: Clarity Before Action
We start every engagement with a scoping call to make sure you understand exactly what will be tested, what the scan will and won't do, and how the results map to real business risk. No jargon dumps, no scare tactics, just a clear picture of your attack surface.
Choose Your Scanning Approach
You have two broad options. Open-source tools like Nmap and OpenVAS give you full control and come at no cost, but they require hands-on expertise to configure, tune, and interpret. Commercial platforms such as Tenable Nessus and Qualys offer polished dashboards and automated scheduling, but carry licensing fees that can stretch a small IT budget.
There is also a middle path. netvuln-tool, the scanning engine we built at Bullium, combines open-source discovery with automated risk scoring and a web-based collection portal. It produces executive-ready reports, tracks remediation status over time, and benchmarks your results against industry peers, all without per-seat licensing. For many SMBs, this blends the transparency of open-source tooling with the polish of a commercial product.
The Bullium Fix: Right-Sized Tooling
We match the scanning tool to your environment and budget. Whether it is a single-subnet office or a multi-site hybrid network, we recommend the approach that gives you the best coverage per dollar, and we handle the configuration so your team can focus on fixing what matters.
Prepare Your Network for the Scan
Running a scan without preparation is like auditing your finances without gathering your bank statements first. Before you press "Start," there are three things to nail down. Scope: decide which subnets, VLANs, and IP ranges are in play. Include wireless segments and any cloud-connected resources if they are accessible from the LAN. Credentials: authenticated scans (where the scanner logs into each host) find significantly more vulnerabilities than unauthenticated scans because they can inspect installed software versions, registry keys, and configuration files. Prepare a dedicated service account with read-only access for this purpose.
Finally, notify stakeholders. Let your team know when the scan will run, so they do not mistake scanner traffic for an attack. If you have an intrusion detection system or a managed firewall, whitelist the scanner's IP address to avoid triggering alerts or getting the scan blocked mid-run.
The Bullium Fix: Guided Preparation
We provide a pre-scan checklist and work directly with your IT team (or MSP) to set up credentials, define the target scope, and schedule the scan window. This avoids false negatives from blocked ports and ensures the results reflect your actual security posture, not just what the scanner could reach without help.
Run the Scan and Interpret the Results
Once the scan completes, you will be looking at a list of findings ranked by severity, typically on a scale from Critical to Informational. Critical and High findings represent vulnerabilities that an attacker could exploit remotely with little effort; Medium findings are real risks but usually require additional conditions to exploit; Low and Informational items are hardening recommendations rather than immediate threats.
The key is not to panic at the total number. A scan of even a modest 50-host network can produce hundreds of findings. Focus on the risk score, which combines severity, exploitability, and asset value into a single number. Sort by risk score and work top-down. Pay special attention to findings tagged with known exploit code or active threat-intelligence references, as these are the vulnerabilities most likely to be targeted in the wild.
The Bullium Fix: Expert Triage
Raw scan data is only useful if someone knows how to read it. Our security consulting team reviews every finding, filters out false positives, and delivers a prioritized remediation report with plain-language explanations. You get a ranked action list, not a spreadsheet of CVE numbers.
Act on Findings and Establish an Ongoing Cadence
A scan report sitting in someone's inbox does nothing to reduce risk. The real value comes from the remediation cycle: patch the critical items, re-scan to confirm the fixes took effect, and document any accepted risks with a formal exception. For most SMBs, a quarterly scanning cadence strikes the right balance between visibility and operational overhead. Organizations in regulated industries or those handling sensitive data may need monthly scans to satisfy compliance frameworks like PCI-DSS, SOC 2, or NIST CSF.
Beyond the cadence, build scanning into your change management process. Every time you deploy a new server, open a firewall port, or onboard a new SaaS integration, run a targeted scan against the affected assets. This turns vulnerability management from a periodic chore into a continuous feedback loop that catches misconfigurations before they become breaches.
The Bullium Fix: Continuous Visibility
Our netvuln-tool platform supports scheduled, automated scans with trend dashboards that track your risk score over time. You can see whether your remediation efforts are moving the needle, compare results across scan cycles, and generate compliance-ready reports on demand. We handle the ongoing operation so your team stays focused on fixes, not scanner maintenance.
Ready to See What's on Your Network?
Whether this is your first vulnerability scan or you are looking to replace an outdated process, Bullium Consulting can get you from zero to a prioritized remediation plan in days, not weeks.