Tag Archives: exploit

Microsoft Patch Tuesday March 2022

Hello everyone! I am glad to greet you from the most sanctioned country in the world. Despite all the difficulties, we carry on. I even have some time to release new episodes. This time it will be about Microsoft Patch Tuesday for March 2022.

Alternative video link (for Russia): https://vk.com/video-149273431_456239076

I do the analysis as usual with my open source tool Vulristics. You can still download it on github. I hope that github won’t block Russian repositories and accounts, but for now it looks possible. Most likely, I will just start hosting the sources of my projects on avleonov.com in this case. Or on another domain, if it gets even tougher. Stay tuned.

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Last Week’s Security news: Exploits for ForgeRock, vSphere, Apache Tomcat, new Print Spooler vuln, Kaseya Patch and REvil, SolarWinds, Schneider Electric, Bulletins

Hello guys! The fourth episode of Last Week’s Security news, July 12 – July 18.

I would like to start with some new public exploits. I think these 4 are the most interesting.

  • If you remember, 2 weeks ago I mentioned the ForgeRock Access Manager and OpenAM vulnerability (CVE-2021-35464). Now there is a public RCE exploit for it. ForgeRock OpenAM server is a popular access management solution for web applications. Michael Stepankin, Researcher: “In short, RCE is possible thanks to unsafe Java deserialization in the Jato framework used by OpenAM”. And now this vulnerability is Under Active Attack. “The [Australian Cyber Security Centre] has observed actors exploiting this vulnerability to compromise multiple hosts and deploy additional malware and tools,” the organization said in an alert. ACSC didn’t disclose the nature of the attacks, how widespread they are, or the identities of the threat actors exploiting them”.
  • A new exploit for vSphere Client (CVE-2021-21985). The vSphere Client (HTML5) contains a remote code execution vulnerability due to lack of input validation in the Virtual SAN Health Check plug-in which is enabled by default in vCenter Server. A malicious actor with network access to port 443 may exploit this issue to execute commands with unrestricted privileges on the underlying operating system that hosts vCenter Server.
  • Apache Tomcat 9.0.0.M1 – Open Redirect (CVE-2018-11784). “When the default servlet in Apache Tomcat […] returned a redirect to a directory […] a specially crafted URL could be used to cause the redirect to be generated to any URI of the attackers choice”.
  • Apache Tomcat 9.0.0.M1 – Cross-Site Scripting (CVE-2019-0221). “The SSI printenv command in Apache Tomcat […] echoes user provided data without escaping and is, therefore, vulnerable to XSS”. However, in real life this is unlikely to be used. “SSI is disabled by default. The printenv command is intended for debugging and is unlikely to be present in a production website”.
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Microsoft Patch Tuesday September 2020: Zerologon and other exploits, RCEs in SharePoint and Exchange

I would like to start this post by talking about Microsoft vulnerabilities, which recently turned out to be much more serious than it seemed at first glance.

Older Vulnerabilities with exploits

“Zerologon” Netlogon RCE (CVE-2020-1472)

One of them is, of course, the Netlogon vulnerability from the August 2020 Patch Tuesday. It’s called “Zerologon”. I would not say that Vulnerability Management vendors completely ignored it. But none of them (well, maybe only ZDI) emphasized in their reports that this vulnerability would be a real disaster.

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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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Vulnerability Life Cycle and Vulnerability Disclosures

Vulnerability Life Cycle diagram shows possible states of the vulnerability. In a previous post I suggested to treat vulnerabilities as bugs. Every known vulnerability, as same as every bug, was implemented by some software developer at some moment of time and was fixed at some moment of time later. What happens between this two events?

Vulnerability life-cycle

Right after the vulnerability was implemented in the code by some developer (creation) nobody knows about it. Well, of course, if it was done unintentionally. By the way, making backdoors look like an ordinary vulnerabilities it’s a smart way to do such things. 😉 But let’s say it WAS done unintentionally.

Time passed and some researcher found (discovery) this vulnerability and described it somehow. What’s next? It depends on who was that researcher.

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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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Guinea Pig and Vulnerability Management products

IMHO, security vendors use the term “Vulnerability Management” extremely inaccurate. Like a guinea pig, which is not a pig and is not related to Guinea, the current Vulnerability Management products are not about the actual (practically exploitable) vulnerabilities and not really about the management.

Guinea Pig and Vulnerability Management

Vulnerability should mean something solid and reliable, something that can be practically used by a malicious attacker or penetration tester.

When (so-called) Vulnerability Management vendors start working with indirect information from third-party about potential vulnerabilities in the software, that were possibly exploited by someone in some unknown conditions, or simply distance from responsibility: “we just provide information from the software vendor; software vendor knows better about the vulnerabilities in his own products”, it’s all falling into to the area of fortune telling and counting angels on the head of a pin.

Hardcore process of identifying weaknesses that real-life attackers can use moves to a boring compliance. For example, as PCI DSS requires, there should be no vulnerabilities above medium level (CVSS Base score > 4). At the same time, no one cares how fair this assessment of criticality is or how real these vulnerabilities are. All the analytics build on such formal data loses its sharpness and practical value.

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