Tag Archives: CVE

Microsoft Patch Tuesday April 2020: my classification script, confusing RCE in Adobe Type Manager and updates for older vulnerabilities

Easiest task ever?

Making the reviews of Microsoft Patch Tuesday vulnerabilities should be an easy task. All vulnerability data is publicly available. Even better, dozens of reviews have already been written. Just read them, combine and post. Right?

Microsoft Patch Tuesday April 2020: my classification script, confusing RCE in Adobe Type Manager and updates for older vulnerabilities

Not really. In fact it is quite boring and annoying. It may be fun to write about vulnerabilities that were already used in some real attacks. But this is a very small part of all vulnerabilities. What about more than a hundred others? They are like “some vulnerability in some component may be used in some attack (or may be not)”. If you describe each of them, no one will read or listen this.

You must choose what to highlight. And when I am reading the reports from Tenable, Qualys and ZDI, I see that they choose very different groups of vulnerabilities, pretty much randomly.

My classification script

That’s why I created a script that takes Patch Tuesday CVE data from microsoft.com and visualizes it giving me helicopter view on what can be interesting there. With nice grouping by vulnerability type and product, with custom icons for vulnerability types, coloring based on severity, etc.

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Microsoft Patch Tuesday March 2020: a new record was set, SMBv3 “Wormable” RCE and updates for February goldies

SMBv3 “Wormable” RCE

Without a doubt, the hottest Microsoft vulnerability in March 2020 is the “Wormable” Remote Code Execution in SMB v3 CVE-2020-0796. The most commonly used names for this vulnerability are EternalDarkness, SMBGhost and CoronaBlue.

Microsoft Patch Tuesday for March 2020: a new record was set, SMBv3  "Wormable" RCE and updates for February goldies

There was a strange story of how it was disclosed. It seems like Microsoft accidentally mentioned it in their blog. Than they somehow found out that the patch for this vulnerability will not be released in the March Patch Tuesday. So, they removed the reference to this vulnerability from the blogpost as quickly as they could.

But some security experts have seen it. And, of course, after EternalBlue and massive cryptolocker attacks in 2017, each RCE in SMB means “OMG, this is happening again, we need to do something really fast!” So, Microsoft just had to publish an advisory for this vulnerability with the workaround ADV200005 and to release an urgent patch KB4551762.

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Vulnerability Management Product Comparisons (October 2019)

Here I combined two posts [1.2] from my telegram channel about comparisons of Vulnerability Management products that were recently published in October 2019. One of them was more marketing, published by Forrester, the other was more technical and published by Principled Technologies.

Vulnerability Management Product Comparisons (October 2019)

I had some questions for both of them. It’s also great that the Forrester report made Qualys, Tenable and Rapid7 leaders and Principled Technologies reviewed the Knowledge Bases of the same three vendors.

Let’s start with Forrester.

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PHDays 9: new methods of Vulnerability Prioritization in Vulnerability Management products

On May 21, I spoke at the PHDays 9 conference. I talked about new methods of Vulnerability Prioritization in the products of Vulnerability Management vendors.

PHDays9 new ways of prioritizing vulnerabilities

During my 15 minutes time slot I defined the problems that this new technology has to solve, showed why these problems could NOT be solved using existing frameworks (CVSS), described what we currently have on the market and, as usual, criticized VM vendors and theirs solutions a little bit. ?

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Vulnerability Management at Tinkoff Fintech School

In the last three weeks, I participated in Tinkoff Fintech School – educational program for university students. Together with my colleagues, we prepared a three-month practical Information Security course: 1 lecture per week with tests and home tasks.

Each lecture is given by a member of our security team, specialized in one of the following modules: Vulnerability Management, Application Security, Infrastructure Security, Network Security, Virtualization Security, Banking Systems Security, Blue & Red-teaming, etc.

Vulnerability Management at Tinkoff Fintech School

The course is still ongoing, but my Vulnerability Management module is over. Therefore, I want to share my impressions and some statistics.

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Martian Vulnerability Chronicles

Well, there should have been an optimistic post about my vulnerability analysis & classification pet-project. Something like “blah-blah-blah the situation is pretty bad, tons of vulnerabilities and it’s not clear which of them can be used by attackers. BUT there is a way how to make it better using trivial automation“. And so on. It seems that it won’t be any time soon. ¯\_(ツ)_/¯

I’ve spent several weekends on making some code that takes vulnerability description and other related formalized data to “separate the wheat from the chaff”. And what I get doesn’t look like some universal solution at all.

Pretty frustrating, but still an interesting experience and great protection from being charmed by trendy and shiny “predictive prioritization”.

Martian Vulnerability Chronicles

Literally, when you start analyzing this vulnerability-related stuff every your assumption becomes wrong:

  • that vulnerability description is good enough to get an idea how the vulnerability can be exploited (let’s discuss it in this post);
  • that CVSS characterizes the vulnerability somehow;
  • that the links to related objects (read: exploits) can be actually used for prioritization.

Actually, there is no reliable data that can be analyzed, trash is everywhere and everybody lies 😉

Let’s start from the vulnerability description. Great example is the last week critical Linux kernel vulnerability CVE-2019-8912.

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What’s wrong with patch-based Vulnerability Management checks?

My last post about Guinea Pigs and Vulnerability Management products may seem unconvincing without some examples. So, let’s review one. It’s a common problem that exists among nearly all VM vendors, I will demonstrate it on Tenable Nessus.

If you perform vulnerability scans, you most likely seen these pretty huge checks in your scan results like “KB4462917: Winsdows 10 Version 1607 and Windows Server 2016 October 2018 Security Update“. This particular Nessus plugin detects 23 CVEs at once.

What's wrong with patch-centric Vulnerability Management?

And, as you can see, it has formalized “Risk Information” data in the right column. There is only one CVSS score and vector, one CPE, one exploitability flag, one criticality level. Probably because of architectural limitations of the scanner. So, two very simple questions:

  • for which CVE (of these 23) is this formalized Risk Information block?
  • for which CVE (of these 23) exploit is available?

Ok, maybe they show CVSS for the most critical (by their logic) CVE. Maybe they somehow combine this parameter from data for different CVEs. But in most cases this will be inaccurate. Risk information data for every of these 23 vulnerabilities should be presented independently.

As you can see on the screenshot, one of these vulnerabilities is RCE the other is Information Disclosure. Vulnerability Management solution tells us that there is an exploit. Is this exploit for RCE or DoS? You should agree, that it can be crucial for vulnerability prioritization. And more than this, in the example there are 7 different RCEs in Internet Explorer, MSXML parser, Windows Hyper-V, etc. All this mean different attack scenarios. How is it possible to show it Vulnerability Scanner like one entity with one CVSS and exploitability flag? What can the user get from this? How to search in all this?

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