Vulnerability Management – Running a Nessus Scan

Today, I used a tool called “Nessus” which is a Vulnerability Management tool. What is Vulnerability Management? Vulnerability Management is a process that involves identifying, assessing, prioritizing, and reducing vulnerabilities in systems, networks, etc. The goal of this is to lower the chances of a security breach or attack by finding vulnerabilities before they can be exploited.

First we created a Nessus account and went through the installation process.

Set up Windows 10 Pro on our Virtual Machine.

While setting up this Virtual Machine, I ran into the issue that it could not connect to the internet. First I noticed the lower right network icon saying there was no internet connection. I ran the ipconfig command and got an APIPA IP Address.

I tried restarting the VM. Didn’t work. I went online and searched for solutions. On the VMWare settings I switched the Network Adapter connection to NAT instead of Bridged. After this, I finally had Internet connectivity. But for this project I needed it to be Bridged. As you can see NAT makes the VM share the hosts IP address. So if we ran a Nessus scan while in NAT mode I’m not sure how Nessus was going to react when its trying to scan two machines who are sharing the same IP address. Or if it would even be scanning the correct machine. So I needed this to work in Bridged mode.

I continued doing research until I came upon a forum. After going through the entire forum thread, I found the fix. I had to disable all the unnecessary network adapters I had on my host machine and to only have one adapter enabled (the one that’s connecting to the internet on your host machine.) Which for us, was the NETGEAR A7000 WiFi USB3.0 Adapter. As you can see in the screenshot above, that’s the only one I left enabled.

After doing this and restarting the Virtual Machine, I finally was able to connect to the Internet. I ran the ipconfig command and I was finally getting a normal IP Address instead of a 169 APIPA address.

Next, I am setting up a basic network scan on Nessus. To specify which machine you want to scan, all you have to do is paste the IP Address of the machine in the “Targets” field.

After running this first (super basic) scan, you can see I had 1 vulnerability that was classified as “high.” But I wanted a more in depth scan.

To allow a more in depth scan, first I needed to enable Remote Registry on the VM. Remote registry allows access to the central database that stores all of the machines configuration, settings, and applications on the machine remotely.

Now, to run a more in depth scan of our VM and find vulnerabilities, you run what’s called a Credentialed Scan. Here, you enter the machines username and password in here.

With the images above you can clearly see that the credentialed scan is able to perform a much more in-depth scan of your overall system, finding more vulnerabilities.

A lot of them had to do with the fact that Windows on the Virtual Machine was not up to date. To fix these, I updated Windows several times on the Virtual Machine. And ran the scan again. The scan showed a lot less vulnerabilities then before.

Overall, Nessus is a Vulnerability Management tool that allows you to scan machines so you can find and fix vulnerabilities before an attacker exploits them and can end up costing your company millions of dollars. Is it possible to perform this type of scan without Nessus? Yes, there’s probably other tools out there, and there’s probably ways you can do it manually. But if your organization is huge I doubt you would want your IT department going through each machine connected to your network manually.

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