Tag Archives: CVSS

Downloading and analyzing NVD CVE feed

In previous post “New National Vulnerability Database visualizations and feeds” I mentioned JSON NVD feed.

NVD JSON feed parse python

Let’s see what data it contains, how to download and analyse it. First of all, we need to download all files with CVEs from NVD database and save them to some directory.

nvd feed json download

Unfortunately, there is no way to download all the content at once. Only one year archives. We need to get urls first. Url looks like this: https://static.nvd.nist.gov/feeds/json/cve/1.0/nvdcve-1.0-2017.json.zip. Then we will download them all.

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New National Vulnerability Database visualizations and feeds

Recently, the National Institute of Standards and Technology (NIST) introduced a new version of National Vulnerability Database (NVD) website.

NIST NVD new site

I will not say that I liked this redesign:

new NVD website

IMHO, old website with US flag was much prettier and useful:

old NVD website

But the very fact that the site is developing, I really like very much. Let’s see what’s new there.

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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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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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Vulnerability Quadrants

Hi everyone! Today I would like talk about software vulnerabilities. How to find really interesting vulnerabilities in the overall CVE flow. And how to do it automatically.

Vulnerability Quadrant

First of all, let’s talk why we may ever need to analyze software vulnerabilities? How people usually do their Vulnerability Management and Vulnerability Intelligence?

VM strategies

  • Some people have a Vulnerability scanner, scan infrastructure with it, patch founded vulnerabilities and think that this will be enough.
  • Some people pay attention to the vulnerabilities that are widely covered by media.
  • Some people use vulnerability databases and search for the most critical vulnerabilities by some criteria.

Each of these ways have some advantages and some disadvantages.

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