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Passive and Active vulnerability scanning

Passive and active vulnerability scanning are two approaches to finding weaknesses in an organization’s network. Weaknesses that cybercriminals could maliciously exploit.

Every organization must run both passive and active vulnerability scans regularly. This is the only way to stay ahead of the cybercriminals who are running the same scans. The difference, however, is that hackers use scans to compromise your assets, whereas you use scans to close the holes and protect your assets.

What is passive vulnerability scanning?

Passive vulnerability scanning captures traffic transversing the network and analyzes that traffic, looking for known vulnerabilities. Examples of passive vulnerability scanning include capturing traffic over the air, looking for rogue WiFi Access Points, or capturing traffic over the wired network, checking only the latest TLS version is in use.

Passive vulnerability scans detect network weaknesses without disrupting normal network operations.

What is active vulnerability scanning?

Active vulnerability scanning sends out packets in an attempt to get the network to respond. It analyzes the network responses, looking for known vulnerabilities. An example of active vulnerability scanning is sending an ICMP message with the IP address of a firewall and seeing if the firewall responds.

Active vulnerability scans look for a weakness rather than wait for the weakness to appear. Therefore, active scanning is more effective at finding vulnerabilities than passive scanning. Active vulnerability scans can also be used to simulate a network attack or to help assess how a hacker penetrated the network after a breach has occurred.

Comparing the risks associated with passive and active vulnerability scans

There are risks when performing an active vulnerability scan. An active scan interjects traffic into the network, which may negatively impact network performance. In addition, Intrusion Detection/Prevention Systems (IDS/IPS) may detect the injected traffic, triggering alarms and preemptive actions, such as resetting connections.

Extreme care and coordination are required when running active vulnerability scans to minimize the impact on low latency and critical business systems. Check out NetAlly’s checklist for lessening the risks associated with active vulnerability scanning.

In comparison, the risks of running a passive vulnerability scan are minimal. Passive scans have little to no impact on the network and do not trigger a response from any Intrusion Detection/Prevention System (IDS/IPS).

Three questions to ask now

Ideally, an organization should perform both passive and active vulnerability scans. Both scan types allow an organization to identify weaknesses in the enterprise network. Active vulnerability scanning provides a more complete picture of network vulnerabilities but runs the risk of disrupting network operations.

When passive and active vulnerability scans should vary based on an organization’s security objectives and business environment. For example, an organization may run passive vulnerability scans periodically throughout the day and active scans monthly.

It is time for you to ask three essential security questions:

  1. Does your organization perform passive and active vulnerability scans regularly?
  2. Are these scans performed frequently enough to meet the organization’s security objectives?
  3. What tool is being used to perform these scans?

CyberScope vulnerability scanning strengthens the network edge

Unique in the industry, CyberScope is a portable, hand-held tool for conducting cyber security assessments at the network edge. CyberScope integrates three powerful tools, Discovery, Nmap, and AutoTest, to detect all connected endpoint devices, identify network vulnerabilities, and automate active and passive scans. It provides valuable insights for network and security teams about weaknesses in the most vulnerable part of the network, the edge.

Combining CyberScope with Link-Live™, a platform for collaboration, reporting, and analytics, allows IT teams to maintain situational awareness of the network’s cybersecurity status. Link-Live provides intuitive network topology mapping, wireless heatmaps, and automated discovery monitoring that detect new, missing, transitory endpoints and changes to the infrastructure. Link-Live includes cybersecurity assessment reports for compliance and audit evidence.

NetAlly has developed a Cybersecurity Assessment Workflow that combines CyberScope and Link-Live to simplify maintaining a strong, edge security posture. 

Author Bio –
Wireless & Cyber Security Expert

Dr. Avril Salter is an author and acclaimed public speaker with over 20 years of in-depth technical and executive experience working in wireless and network security. She holds senior business and technical architect positions with a history of success in setting direction in major corporations and start-ups. She has an exceptional breadth of technical expertise in wireless standards and network security protocols and is a strategic thinker with a solid understanding of the IT and telecommunications industries.