How Do You Perform an Effective Network Security Assessment?
What Is a Network Security Assessment?
A network security assessment is a structured process to identify, analyze, and prioritize risks across your network infrastructure. It evaluates how effectively your environment prevents, detects, and responds to threats.
Assessments reveal:
- Misconfigured devices and unpatched systems
- Open ports and vulnerable services
- Cloud drift and remote access weaknesses
- Segmentation and access control issues
In 2025, assessments cover hybrid networks, including cloud platforms, remote endpoints, and third-party ecosystems.
Why Network Assessments Matter More Than Ever
Network perimeters have dissolved in recent years. With remote work, cloud expansion, and growing supply chain exposure, networks now span on-premise environments, SaaS platforms, and vendor systems.
The risk is showing up in the data. SecurityScorecard latest third-party breach research shows:
- 41.4% of ransomware cases are linked to exposed third-party breaches
- Frequent cloud drift and shadow IT introduce blind spots
Regular assessments reduce your external attack surface, validate controls, and expose weak links inside and outside your environment.
Key Steps in a Network Security Assessment
1. Define the Scope
- Determine if the assessment is internal, external, or both
- Include cloud, remote, and third-party assets
- Map all infrastructure, from physical to virtual and container-based
2. Perform Asset Inventory
- Discover all connected assets using automated tools
- Identify rogue, shadow, and unmanaged endpoints
- Tag assets by criticality, ownership, and internet exposure
3. Run Vulnerability Scanning
Use authenticated and unauthenticated vulnerability scanning tools like:
- Nessus
- Qualys
- OpenVAS
Focus on:
- Common Vulnerabilities and Exposures (CVEs) and outdated software
- Exposed protocols and services
- Weak authentication mechanisms
4. Conduct Port Analysis
Once vulnerabilities are identified, the next step is to examine how they may be exposed, beginning with open ports and the services behind them.
- Identify open TCP and UDP ports
- Analyze exposed services such as SMB, RDP, FTP
- Flag legacy protocols
SecurityScorecard’s global internet-scanning framework can augment this by fingerprinting services across the internet-facing footprint.
5. Perform Firewall and IDS/IPS Audit
- Conduct a full firewall review for “any-to-any” or overly permissive rules
- Validate IDS/IPS coverage and alerting capabilities
- Confirm controls are aligned with the principle of least privilege
Proper configuration and coverage of these tools can dramatically improve early threat detection and containment.
6. Evaluate Network Segmentation
- Confirm segmentation across VLANs, Virtual Private Clouds (VPCs), and cloud-native environments
- Test policy enforcement for sensitive systems and privileged users
- Ensure segmentation blocks lateral movement of attacker
7. Include Penetration Testing
While segmentation helps contain threats, penetration testing goes a step further by actively simulating attacker behavior to validate those controls. Penetration testing can add value by simulating real-world attacks:
- Attempt privilege escalation, credential abuse, and data exfiltration
- Combine phishing and social engineering with technical exploits
This stage is essential to compare pen testing vs scanning results—and validate which vulnerabilities are truly exploitable. SecurityScorecard offers pentesting services to help security teams gain in-depth assessments on vulnerabilities and potential entry-points for attackers to ultimately build resilience for the future.
Integrating Supply Chain Risk
Your network now includes every vendor you use. Attackers will exploit gaps in your vendor ecosystem, so in 2025 your network assessment is incomplete unless it accounts for every vendor connected to it.
SecurityScorecard’s Supply Chain Detection and Response (SCDR) adds continuous visibility into:
- Third-party ports exposed to the internet
- Unpatched software across supplier networks
- Botnet beacons or ransomware staging activity
- Weak TLS configurations or misconfigured firewalls
This data can complement internal scans and highlight inherited risk from partner environments.
Prioritizing Risks from Network Assessments
After conducting a network assessments, it’s crucial to contextualize the information gleaned. Use a matrix that combines:
- Asset criticality (data sensitivity, business function)
- Exposure (public vs internal)
- Exploitability (known vulnerabilities, active threats)
- Business impact
A public-facing asset with a known exploited CVE, for instance, would be urgent, while an internal dev server with outdated software, a vendor with a weak cipher suite, and a misconfigured guest Wi-Fi may be considered less urgent. A well-built risk matrix ensures that limited resources are focused where they matter most.
Reporting and Remediation
After assessment, deliver a structured report that includes:
- Executive summary for non-technical stakeholders
- Technical findings with severity ratings
- Proof-of-concept examples
- Clear vulnerability remediation timelines and accountability
SecurityScorecard helps organizations track and measure risk reduction by offering dynamic security ratings and visibility into network risk reduction over time across vendor ecosystems.
Best Practices for Continuous Network Security
- Perform assessments regularly, such as quarterly or monthly. Consider performing them more often especially in high-risk sectors.
- Reassess after:
- Major infrastructure changes
- M&A or organizational shifts
- Supplier onboarding or critical access updates
- Continuously monitor with automated tools and managed services.
Final Takeaway
In 2025, a network security assessment must extend across hybrid infrastructure, detect cloud drift, audit firewall and IDS/IPS controls, and account for supply chain exposure. Today’s attackers exploit every link in the chain, but a robust assessment is a great first step in being able to break up their attack patterns.
SecurityScorecard empowers organizations to continuously map, monitor, and secure their networks through advanced scanning, port analysis, segmentation testing, and third-party visibility. SecurityScorecard scans more than 3.9 billion IPs over 1,400 ports every day.*
* Daily scanning is for paid customers and their followed vendors. Scanning is approximately weekly for remaining scorecards.
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SecurityScorecard’s MAX is a fully managed service that combines our advanced platform with expert driven remediation. We handle the complexities of supply chain cybersecurity, allowing you to focus on your strategic business operations.
