Nessus¶
Vulnerability scanner from Tenable that identifies missing patches, misconfigurations, and known vulnerabilities.
When I Use It¶
- Baseline vulnerability scanning across a network in scope
- Confirming patch levels and finding low-hanging known vulnerabilities before manual testing
- Producing a scan report to hand off alongside manual findings
Nessus is a starting point, not the engagement. Its output needs validation; a scanner finding is a lead until confirmed by hand.
Installation¶
Download and install from Tenable. Nessus Essentials is free for a limited number of hosts.
Common Tasks¶
| Step | What to Do |
|---|---|
| Configure the scanner | Set scan targets, speed, and reporting options |
| Create a scan policy | Choose the checks: vulnerability, compliance, web |
| Launch the scan | Point it at the in-scope targets |
| Review results | Sort by severity; read each finding's detail and remediation |
| Report | Export for stakeholders or to pair with manual findings |
Reading the Output¶
- Treat Critical and High findings as leads to validate, not confirmed vulnerabilities
- Watch for false positives on version-based checks, which flag a version without confirming exploitability
- The remediation text per finding is useful source material for the report's recommendations
Related¶
- Nmap, for the host and service discovery that scoping a scan depends on
- Metasploit, to validate exploitable findings
- Critical CVE context