Tag Archives: OpenVAS

Problems of Vulnerability Prioritization and Detection

Problems of Vulnerability Prioritization and Detection. It’s the third part of our talk with Daniil Svetlov at his radio show “Safe Environment” recorded 29.03.2017. In this part we talk about Vulnerability Prioritization and Detection:

  • Common Vulnerability Scoring System (CVSS)
  • Environmental factor
  • Manual and  automated vulnerability detection
  • Unauthenticated and authenticated  scanning
  • Why vulnerability scanners are so expensive and why the can’t detect everything

Scanner does not detect all vulnerabilities

Video with manually transcribed Russian/English subtitles:

Prioritization

– Here also the question how to prioritize vulnerabilities properly. Because if you have, as you said, two Linux servers and 20 workstations running Windows, then in principle, you may not need to do prioritization. But if you have fifteen hundred servers: some of them are on perimeter, some are in your DMZ, some are in the internal network. It is still necessary, probably, to understand correctly which vulnerabilities and where should be patched in in the first place.

Yes, this is absolutely true and it’s a very good question. How to prioritize?

Common Vulnerability Scoring System

A natural way. If we look at vulnerabilities with a CVE identifier, for them in the US National Vulnerability Database we can find CVSS Base Score. It is an assessment of vulnerability criticality level.

How is it calculated?

Some person fills the questionnaire: can it be remotely exploited – no, is there public exploit – no, etc.

CVSS framework

The result is a CVSS vector – this is a line in which you can see the main characteristics of this vulnerability and CVSS Base score is the score from 0 to 10 depending on criticality.

This is a natural way of prioritization. But sometimes this method does not give very good results.

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Great OpenVAS news: delay in plugin feed will be dropped, new GVM-Tools for remote management released

Great OpenVAS news: delay in plugin feed will be dropped, new GVM-Tools for remote management released. Jan Oliver Wagner, CEO of Greenbone and OpenVAS Community leader sent recently several messages to community email list with the great news.

First of all, Greenbone decided to drop two weeks delay in a free plugin feed, that was implemented in June 2017 and made some OpenVAS users pretty nervous.

I wrote about it in “GSM Community Edition and lagging OpenVAS Plugin Feed“. The good thing is that, it has increased interest in NASL scripting among OpenVAS users. I also made some steps in this way in “Adding third party nasl plugins to OpenVAS“. I don’t now why Greenbone finally decided to drop this delay, but I am very glad for this decision. Wise move!

The feed will stay delayed until September 4th, 2017. To demonstrate the current state I used some data from Vulners.com collections. Let’s see the nasl vulnerability detection plugins for CentOS in Nessus and OpenVAS. I know that Windows would be much more clear, but Microsoft released latest MS17-023 bulletin in March, so now there is no much difference there.

CentOS Nessus Openvas 2 week delay

As you can see, no OpenVAS plugins since 2017-08-16, literally two weeks. And I hope this will change very soon.

Don’t forget that NVT will be called now GCF (Greenbone Community Feed) and some advanced enterprise-level checks will be now released only in paid feed.

Another good news is the recent release of open source GVM-Tools for controlling OpenVAS remotelly. It will replace old console client openvas-cli (omp). Let’s try to download and install it on Debian host with installed OpenVAS (see “Installing OpenVAS 9 from the sources“).

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What’s inside Vulners.com database and when were security objects updated last time

What’s inside Vulners.com database and when were security objects updated last time. As I already wrote earlier, the main advantage of Vulners.com, in my opinion, is openness. An open system allows you to look under the hood, make sure that everything works fine and ask developers uncomfortable questions why there were no updates for a long time for some types of security objects.

You can do this by using the https://vulners.com/api/v3/search/stats/ request, that I already mentioned in “Downloading entire Vulners.com database in 5 minutes

First of all, let’s look at the security objects. This will give us an understanding of Vulners.com basis.

Vulners objects

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GSM Community Edition and lagging OpenVAS Plugin Feed

GSM Community Edition and lagging OpenVAS Plugin Feed. As I already wrote in “Installing OpenVAS 9 from the sources“, since May 2017 OpenVAS 9 is available in a form of free virtual appliance. It is called GSM Community Edition (GCE) and is based on Greenbone commercial product GSM ONE.

What’s the difference between GSM ONE and free GCE? GSM Community Edition uses different Community Feed of NASL plugins, it can’t be updated automatically and does not have some management features. The most important, in my opinion, is that it does not support OpenVAS Management Protocol (OMP), API for managing scanners. Only HTTPS for WebGUI and SSH are available.

GSM start screen

Talking about different NASL plugin feeds, I need to mention recent message by Jan-Oliver Wagner in Openvas-announce list.

That seems like Greenbone is rather tired of developing OpenVAS by themselves and watching how other companies use theirs engine and feeds, positioning themselves as an “alternative to Greenbone’s product at a better price”. So, they decided:

  1. “OpenVAS NVT Feed” will be renamed to “Greenbone Community Feed”
  2. Public access to the “openvas-nvts” SVN repository will be forbidden, but the license of nasl plugins won’t be changed.
  3. Now Community Feed lags 14 days from commercial feed, but Greenbone would like to make an actual feed, but without some features for enterprise customers.

I really care about Greenbone and they, of course, do as they think is better for the company and OpenVAS community, but at the same time it reminds me situation with Tenable and Nessus. Maybe not so radical. But definitely in the same direction.

Feed delayed for 2 week can’t be used effectively for obvious reasons. If you see exploitation of critical vulnerability like WannaCry in the wild and will need to wait 2 weeks to check your infrastructure, it’s a nonsense! 🙂 That’s mean that you just can’t rely on OpenVAS anymore. And if you use it, you should think about migration on commercial solution, for example on Greenbone’s GSM, or think about getting actual plugin feed somewhere else.

The good thing, it might show customers once again that knowledge base of Vulnerability Management solution is important and stimulate other security content developers to make own nasl scripts and feeds.

But let’s go back to GSM Community Edition. Detailed description of installation process you can find on official site. I will just describe my own experience.

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PHDays VII: To Vulnerability Database and beyond

PHDays VII: To Vulnerability Database and beyond. Last Tuesday and Wednesday, May 23-24, I attended PHDays VII conference in Moscow. I was talking there about vulnerability databases and the evolution process of vulnerability assessment tools, as far as I understand it.

To Vulnerability Database and beyond

But first of all, a few words about the conference itself. I can tell that since the last year the event got even better. I’ve seen lot of new faces. Some people I didn’t know, but they knew me by my blog and accounts in social networks. What a strange, strange time we live in! I was very pleased to see and to talk with you all, guys! 🙂

PHDays is one of the few events that truly brings all Russian community of security professionals together. I’ve seen people I have studied with in university, colleagues from the all places where I have been worked, and nearly all researchers and security practitioners that I follow. Big thanks for the organizers, Positive Technologies, for such an amazing opportunity!

It is also a truly international event. You can see speakers from all over the world. And all information is available both in Russian and English. Almost all slides are in English. Three parallel streams of reports, workshops and panel discussions were dubbed by professional simultaneous interpreters, like it is a United Nations sessions or something, recorded and broadcast live by the team of operators and directors. Final result looks really great.

Video of my presentation:

I was talking too fast and used some expressions that was hard to translate. The translator, however, did an awesome job. He is my hero! 🙂 If you didn’t understand something on video, I made a transcript bellow.

A version without translation for Russian-speakers is here.

Slides:

Unfortunately gif animation is not working in the Slideshare viewer.

Today I would like to discuss vulnerability databases and how vulnerability assessment systems has been evolving. Prior to discussing vulnerability databases I need to say that any vulnerability is just a software error, a bug, that allowing hacker to do some cool things. Software developers and vendors post information about such vulnerabilities on their websites. And there are tons and tones of vendors, and websites, and software products, and vulnerabilities.

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WannaCry about Vulnerability Management

WannaCry about Vulnerability Management. Nearly all mainstream media wrote today about massive ransomware attacks around the world: 16 medical institutions in UK, strong rumours that huge companies in Russia, and even Russian Ministry of Internal Affairs suffered a damage.

At this moment Kaspersky recorded more than 45,000 attacks in 74 countries around the world, but mostly in Russia. During the attack WannaCry malware encrypts data with the extension “.WCRY” added to the filename – that’s why it is called this way.

WannaCry CryptoLocker

What I like in this WannaCry story, that it’s actually all about Vulnerability Management.

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Installing OpenVAS 9 from the sources

Installing OpenVAS 9 from the sources. upd. 29.09.2018 Unfortunately, the script does not work after Greenbone moved the sources from their internal repository to GitHub. It’s necessary to edit the script. Stay tuned.

In last month Greenbone Networks and OpenVAS development team have finally presented new OpenVAS 9 with new GUI, improved multi-scanner support, improved asset management, etc. We have been waiting for this release for 2 years!

Upd. Please note, that entire procedure for separating scanners onto separate hardware/distributed hardware in different datacenters has changed completely – and that it’s a good idea to get familiar with this new procedure prior to upgrading to OpenVAS 9. 😉

For installing OpenVAS 9 from the sources I used the same script as for OpenVAS 8 installation last year. More details about this script and why you may need it you can read in the post “openvas_commander for OpenVAS installation and management“.

OpenVAS 9 Dashboards

I fixed the script a bit because of these changes in OpenVAS9:

  • openvas-nvt-syncwas renamed to greenbone-nvt-sync
  • openvas-mkcert and openvas-mkcert-client were replaced by openvas-manage-certs

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