Authenticated scan from Nessus getting failed - Azure server

Question

Authenticated scan from Nessus getting failed - Azure server

Abhinand MS 20

We have been required to perform an authenticated vulnerability scan on one of our Azure server. The vendor was able to access the machine with ssh, and informed no major errors are showing but the authenticated scan got failed. They are using Nessus Tool for the scan. Appreciate if anyone can help me on this

Anonymous

2026-01-08T09:49:55.5233333+00:00
Hello @Abhinand MS It sounds like you're facing issues with an authenticated vulnerability scan on your Azure server using the Nessus Tool. Here are some steps you can consider to troubleshoot and potentially resolve the problem:

Check Authentication Method: Ensure that the credentials being used for the authenticated scan are valid and have the necessary permissions. The service principal might require roles assigned in Azure RBAC to successfully execute the scan.

SSH Access: Since the vendor mentioned they could access the machine via SSH without major errors, double-check that the SSH user has sufficient privileges to perform the necessary actions for the scan.

Verify Nessus Configuration:

Ensure the Nessus Agent is correctly installed and configured on the Azure VM. You can review the Tenable One-Click Nessus Agent installation documentation for guidance.

Check if the Nessus Agent is linking to the correct Nessus Manager or Tenable.io with the right linking key.

Security settings in Azure, such as the Azure Firewall, Network Security Groups, etc., might restrict access. Make sure that these configurations don't block the necessary ports or protocols used by Nessus during the scan.

Take a look at the logs generated by the Nessus tool to see if there are any specific errors mentioned that could provide further insight into the failure.

You might find additional troubleshooting tips in the Azure Security Center scan failures documentation which can help diagnose any misconfigurations.

Your answer

Anonymous

2026-01-08T09:49:55.5233333+00:00

Hello @Abhinand MS It sounds like you're facing issues with an authenticated vulnerability scan on your Azure server using the Nessus Tool. Here are some steps you can consider to troubleshoot and potentially resolve the problem:

Check Authentication Method: Ensure that the credentials being used for the authenticated scan are valid and have the necessary permissions. The service principal might require roles assigned in Azure RBAC to successfully execute the scan.

SSH Access: Since the vendor mentioned they could access the machine via SSH without major errors, double-check that the SSH user has sufficient privileges to perform the necessary actions for the scan.

Verify Nessus Configuration:

Ensure the Nessus Agent is correctly installed and configured on the Azure VM. You can review the Tenable One-Click Nessus Agent installation documentation for guidance.

Check if the Nessus Agent is linking to the correct Nessus Manager or Tenable.io with the right linking key.

Security settings in Azure, such as the Azure Firewall, Network Security Groups, etc., might restrict access. Make sure that these configurations don't block the necessary ports or protocols used by Nessus during the scan.

Take a look at the logs generated by the Nessus tool to see if there are any specific errors mentioned that could provide further insight into the failure.

You might find additional troubleshooting tips in the Azure Security Center scan failures documentation which can help diagnose any misconfigurations.