Network vulnerability scanning is the cybersecurity practice of systematically identifying and assessing potential security weaknesses within a computer network. It uses automated tools to find potential areas of risk across your organization’s networks and systems before an attacker does, protecting these systems as well as data.
This process is a crucial part of managing network security. Once network vulnerability scanners find vulnerabilities, network admins can then take steps to fix them, bolstering network defense.
Network vulnerability scanning tools empower organizations to proactively reduce the risk of data breaches, service disruptions, and unauthorized access. Additionally, network vulnerability scanning software enables organizations to comply with regulatory requirements, gain insights into their security posture, and allocate resources effectively.
The network vulnerability scanning process may also incorporate manual testing in certain cases to uncover complex or non-standard vulnerabilities. Regular scanning aids organizations in maintaining a strong security posture, adapting to evolving threats, and keeping up with software updates.
Table of Contents
How network vulnerability scanning works
Network vulnerability scanning is a structured procedure that begins with network assessment and discovery, followed by scanning scope definition, scanner selection, and culminates in the identification and mitigation of network vulnerabilities.
1. Network assessment and discovery
The process starts by identifying and cataloging all devices and systems connected to your network. This inventory includes servers, workstations, routers, firewalls, and other network components.
2. Scanning scope definition
Defining the scope involves determining which assets and services to include in your scan and deciding whether the IT team will conduct the scanning process internally or externally.
3. Scanner selection
Once you define the scope, you must choose an appropriate vulnerability scanning tool or software. This tool should align with the defined scope and have an updated database of known vulnerabilities.
4. Network vulnerability scanning
After selecting a scanner, the actual scanning process begins. The network vulnerability scanning tool methodically checks the network assets within the defined scope for known vulnerabilities. It does this by sending test requests and analyzing responses from network assets to pinpoint potential security weaknesses.
5. Risk mitigation and remediation
Following the scanning phase, network admins or security professionals review the results thoroughly and categorize vulnerabilities based on their severity. This categorization — which often includes labels like critical, high, medium, or low risk — guides subsequent actions.
Your organization can then implement measures to mitigate and remediate the identified vulnerabilities. This may entail applying security patches or reconfiguring systems to reinforce security measures and reduce the risk of unauthorized access or security breaches.
Common vulnerabilities network scans identify
Network scans typically identify vulnerabilities like outdated software, weak passwords, unpatched security, open ports, misconfigured security settings, missing security updates, weak encryption, insecure services and protocols, vulnerable third party components, and denial of service (DoS) vulnerabilities.
- Outdated software: Network scans search for software, operating systems, or firmware lacking the latest security updates, making them susceptible to known exploits.
- Weak or default passwords: They detect systems and devices that still use easily guessable or default login credentials, posing a significant security threat.
- Unpatched security: These scans spot unaddressed vulnerabilities in both software and hardware, which cyberattackers could leverage to compromise a system.
- Open ports: Network vulnerability scans locate open or improperly configured network ports, which can potentially serve as entry points for unauthorized access and attacks.
- Misconfigured security settings: They uncover devices or services with misconfigured security settings, such as granting open access to sensitive directories or incorrectly applied firewall rules, creating security loopholes.
- Missing security updates: Network vulnerability scanners help find and flag missing security updates and patches, which, if not applied, expose systems to known vulnerabilities.
- Weak encryption: They spot weak encryption algorithms and protocols that can undermine the security and privacy of data during transmission and storage.
- Insecure services and protocols: Network scans highlight services and protocols with known security vulnerabilities, making them prime targets for exploitation.
- Vulnerabilities in third-party components: These scans spot vulnerabilities in third-party components, like plugins or libraries, which can be gateways for attackers to infiltrate the system.
- Denial of Service (DoS) vulnerabilities: Network vulnerability scans also detect systems or services at risk of DoS attacks, which can disrupt operations by overwhelming them with malicious traffic or requests.
How to perform a network vulnerability scan
To conduct a vulnerability scan on your network, you need to define your scope, select a scanner, build a plan, initiate the scan, analyze the results, mitigate and remediate, regularly scan, and maintain proper documentation.
1. Define your scope
Clearly outline which network assets and services you want to assess in your vulnerability scan. Decide whether it’s an internal or external scan.
2. Select a scanning tool
Choose a suitable vulnerability scanning tool that aligns with your defined scope and objectives.
3. Prepare and plan
Develop a plan specifying your scan objectives, schedule, and any specific requirements. Inform relevant teams about the plan.
4. Initiate the scan
Launch the scanning tool, configure it according to your scope, and initiate the network vulnerability scan to uncover known vulnerabilities.
5. Analyze the results
Examine the scan results, categorize vulnerabilities by severity, and prioritize urgent ones for immediate action.
6. Mitigate and remediate
Take measures to address identified vulnerabilities, such as updating necessary systems, deploying patches, or fixing system configurations.
7. Perform regular scanning
Schedule routine vulnerability scans to account for new vulnerabilities and maintain a strong security infrastructure.
8. Documentation and reporting
Maintain records of scan results and actions taken. Furthermore, create reports detailing the vulnerabilities detected and the steps for mitigation.
Examples of vulnerability scanners
There are various types of network vulnerability scanners for different purposes. These include web application scanners, authenticated scanners, passive scanners, continuous monitoring scanners, and cloud-based vulnerability scanners.
Web application scanners
These are a subset of vulnerability scanners focusing on vulnerabilities specific to web applications rather than addressing vulnerabilities in the broader network.
This type of network vulnerability scanner specializes in assessing vulnerabilities that require authentication to access.
Passive scanners are a unique type of network vulnerability scanners that monitor network traffic passively but don’t actively scan for vulnerabilities.
Continuous monitoring scanners
These are network vulnerability scanners that zero in on continuous, ongoing scanning to identify changes and new vulnerabilities.
Cloud-based vulnerability scanners
These mainly scan for vulnerabilities in cloud environments but may also encompass broader cloud security assessments.
Different vulnerability scan methods
There are several network vulnerability scanning methods, each designed to detect network weak points. These techniques include remote scanning. agent-based scanning, credential-based scanning, non-credential-based scanning, passive scanning, and active scanning.
This is the universal approach where a scanner sends packets to the target network from a remote location to identify vulnerabilities.
For this method, target devices have agents that constantly monitor and report vulnerabilities back to a central console.
Credential-based scanning employs tools that use valid usernames and passwords to access target systems for a more detailed assessment.
Cybersecurity professionals and ethical hackers commonly use this technique to scan for vulnerabilities without using login credentials or access privileges. This simulates how an unauthorized attacker might search for weaknesses in a system or network from an external standpoint, where access is limited to what’s publicly visible without authenticated entry.
This scanning approach involves the passive monitoring of network traffic to collect information about devices, software, and configurations without actively probing the target systems.
Network vulnerability scanning approach
There are two different types of network vulnerability scanning approaches: external and internal vulnerability scans. This table provides a concise comparison between the two, highlighting their differences in scope, perspective, methodology, purpose, and primary focus.
|External vulnerability scan
|Internal vulnerability scan
|Scope and target
|Public-facing systems and services
|Internal network and systems
|External (outsider’s perspective)
|Internal (insider’s perspective)
|Port scanning, banner grabbing, vulnerability scanning
|Network scanning, configuration assessment
|Identify external vulnerabilities, protect against external threats
|Discover internal vulnerabilities, protect against insider threats
|Protect external attack surface
|Secure internal network assets
8 best practices for scanning networks for vulnerabilities
Best practices for scanning networks for vulnerabilities include gaining proper authorization, keeping an updated inventory, using the right tools, segmenting and isolating systems, scanning regularly, performing credential-based scanning, prioritizing findings, and documenting and reporting results.
1. Gain proper authorization
Always obtain explicit authorization from the network owner or administrator before conducting any vulnerability scans. Unauthorized scanning can lead to legal and security issues.
2. Keep an updated inventory
Maintain an up-to-date inventory of all devices, systems, and software on the network. This helps in understanding the scope and reduces the chances of missing vulnerabilities.
3. Use the right tools
Choose a reliable and up-to-date network vulnerability scanning tool. You should regularly update these tools to incorporate the latest threat intelligence and vulnerability databases.
4. Segment and isolate
Isolate and segment critical systems from less critical ones. This reduces the attack surface and the potential harm during the scanning process.
5. Schedule regular scans
Set up recurrent, scheduled scans rather than scanning haphazardly to ensure consistent network monitoring for vulnerabilities.
6. Use credential-based scanning
When possible, use credential-based scanning to gain deeper insights into the target systems and obtain a more accurate picture of vulnerabilities by accessing internal configurations.
7. Prioritize findings
Not all vulnerabilities are equally urgent. Implement a process for prioritizing and addressing vulnerabilities based on their severity and potential impact.
8. Document and report
Keep a detailed documentation of the scanning process, including the results, remediation steps, and any changes made. Generate in-depth reports to communicate findings with relevant stakeholders.
Top 3 network vulnerability scanning tools
There is a broad selection of network vulnerability scanning tools in the market today. Many of these tools come with rich features and capabilities that can help your organization assess and strengthen its cybersecurity posture. Here are a few of the best network vulnerability scanning tools in 2023:
Qualys Vulnerability Management, Detection, and Response (VMDR)
Qualys VMDR is a powerful tool for managing vulnerabilities in complex IT environments, which can be challenging to secure. The platform stands out for its ability to give additional threat and risk context, helping to identify high-risk network vulnerabilities. This transparency in the rating algorithm facilitates prioritization and alignment among security and IT stakeholders, leading to swift risk remediation.
One key feature of Qualys VMDR is its integration of asset visibility with vulnerability management, offering organizations a clear view of their global assets. It equips enterprises with insight into cyber risk exposure, simplifying the prioritization of vulnerabilities, assets, or asset groups based on business risk.
However, Qualys VMDR requires technical expertise for optimal use. Nonetheless, it excels in providing threat context and asset monitoring, making it valuable for organizations aiming to fine-tune their cybersecurity posture.
ManageEngine Vulnerability Manager Plus
ManageEngine Vulnerability Manager Plus scans and discovers exposed areas on all local and remote office endpoints, as well as roaming devices, to offer you a thorough 360-degree view of your security exposure. It is second to none in network vulnerability scanning and detects known or emerging vulnerabilities across workstations, laptops, servers, web servers, databases, virtual machines, and content management systems.
This solution combines vulnerability scanning, patch management, and security configuration management into one tool, unifying the detection and resolution of security risks from a central location.
However, ManageEngine Vulnerability Manager Plus does not auto-approve vulnerability patches, which means users must manually approve them. Additionally, immediate patch deployment in the system lets you select only up to 50 clients.
The strengths of ManageEngine Vulnerability Manager Plus greatly outweigh its minor weaknesses, establishing it as an invaluable asset in maintaining network security.
SolarWinds Network Vulnerability Detection
SolarWinds Network Vulnerability Detection, a component of the Network Configuration Manager, enables easy scanning of network devices’ firmware for reported Common Vulnerabilities and Exposures (CVEs), maintaining network security and compliance. Network automation is its main feature, allowing for quick deployment of firmware updates to network devices.
The tool effectively prevents unauthorized network configuration changes with its configuration change monitoring and alerting functionalities. Another notable strength is its capability to audit network routers and switches for policy compliance, consistently checking configurations for any non-compliant changes.
But like other network vulnerability scanning tools, SolarWinds Network Vulnerability Detection has weaknesses. For instance, its level of dashboard customization may not match that of some competitors, potentially affecting your ability to tailor the tool to your specific needs. In addition, the platform does not have a free version. Nevertheless, with its significant capabilities in network vulnerability scanning and management, it remains an excellent choice in the industry.
Bottom line: Scan networks for vulnerabilities
Network vulnerability scanning is an indispensable practice for defending your digital infrastructure. It’s a proactive, all-inclusive approach to detecting and addressing vulnerabilities, enabling continuous monitoring and compliance with regulatory standards. By adopting this process as an ongoing security measure and remaining vigilant, you can safeguard your network from potential threats and ensure its long-term security.
A network vulnerability scan is now a high-priority practice for maintaining strong security. It allows you to understand vulnerabilities, prioritize them based on risk, and take the necessary steps to remediate them.
Regular network scanning helps your organization stay one step ahead of potential threats and promotes timely detection and risk mitigation. Remember, the ultimate objective is to shrink the attack surface to its minimum, creating a fortress so robust that it becomes virtually impenetrable for attackers.
Read our complete guide to the best network vulnerability scanning tools, carefully selected and reviewed for a variety of use cases.