Hello everyone! October was an interesting and busy month for me. I started a new job, worked on my open source Vulristics project, and analyzed vulnerabilities using it. Especially Linux vulnerabilities as part of my new Linux Patch Wednesday project. And, of course, analyzed Microsoft Patch Tuesday as well. In addition, at the end of October I was a guest lecturer at MIPT/PhysTech university. But first thing first.
On October 3, I joined the Positive Technologies team. There I will work on developing Vulnerability Management practices. I have already worked at PT for 6 years, from June 2009 to October 2015. And now, exactly 8 years later, I’m here again. I feel very pleasant emotions about this and have many plans. 🤩 I am sure that in the PT team I will be able to implement many cool things for the development of Vulnerability Management in Russia and abroad. 🙂
Hello everyone! This episode will be about the new hot twenty vulnerabilities from CISA, NSA and FBI, Joint cybersecurity advisory (CSA) AA22-279A, and how I analyzed these vulnerabilities using my open source project Vulristics.
Americans can’t just release a list of “20 vulnerabilities most commonly exploited in attacks on American organizations.” They like to add geopolitics and point the finger at some country. Therefore, I leave the attack attribution mentioned in the advisory title without comment.
Hello everyone! This episode will be about relatively recent critical vulnerabilities. Let’s start with Microsoft Patch Tuesday for October 2021. Specifically, with the vulnerability that I expected there, but it didn’t get there.
Autodiscover leak discovered by Guardicore Labs
“Autodiscover, a protocol used by Microsoft Exchange for automatic configuration of clients such as Microsoft Outlook, has a design flaw that causes the protocol to “leak” web requests to Autodiscover domains outside of the user’s domain but in the same TLD (i.e. Autodiscover.com).” Guardicore Labs acquired multiple Autodiscover domains and have captured 372,072 Windows domain credentials in total. It seems Microsoft have chosen to ignore this issue. No CVE, no Outlook or ActiveSync patches. The only fix is to ban the “Autodiscover.” domains on devices.
Elevation of Privilege – Windows Kernel (CVE-2021-40449)
It is a use-after-free vulnerability in the NtGdiResetDC function of the Win32k driver. A detailed technical description is available in Kasperky Securelist post, but, in short, the vulnerability can lead to leakage of kernel module addresses in the computer’s memory. This vulnerability is being exploited in the wild by APT MysterySnail. All servers and desktops should be updated.
Hello everyone! Last Week’s Security News, July 26 – August 1.
Serious Sam in Metasploit
Last week I talked about the Serious Sam vulnerability (CVE-2021-36934), also known as HiveNightmare. The name HiveNightmare comes from the fact that Windows stores its registry data in a small number of proprietary database files called hives. Due to mismanagement of SAM and SYSTEM hives in Windows 10, it is possible for an unprivileged user to read those files and then, for example, extract the account password hashes. An exploit for this vulnerability is now available in Metasploit and it will be much easier for attackers to exploit this vulnerability. The issues is still under investigation by Microsoft and a patch is not currently available, only the list of vulnerable OS versions, however a workaround has been provided.
PetitPotam
At the beginning of last week, PetitPotam (Little Hippo) attack made a lot of noise. It could force remote Windows systems to reveal password hashes that could then be easily cracked.
“The PetitPotam bug is tied to the Windows operating system and the abuse of a remote access protocol called Encrypting File System Remote Protocol (MS-EFSRPC). The protocol is designed to allow Windows systems to access remote encrypted data stores, allowing for management of the data while enforcing access control policies. […] The PetitPotam PoC is a form of manipulator-in-the-middle (MitM) attack against Microsoft’s NTLM authentication system. Next, an attacker uses the file-sharing protocol Server Message Block (SMB) to request access to a remote system’s MS-EFSRPC interface. According to [security researcher Gilles Lionel], this forces the targeted computer to initiate an authentication procedure and share its authentication details via NTLM.
In response to the public availability of the PoC, Microsoft was quick to respond, outlining several mitigation options. For starters, Microsoft recommends disabling NTLM authentication on Windows domain controllers. It also suggests enabling the Extended Protection for Authentication (EPA) feature on AD CS services.”
But there won’t be any special fix. Microsoft: “PetitPotam is a classic NTLM Relay Attack, and such attacks have been previously documented by Microsoft along with numerous mitigation options to protect customers.”
The question is: do we really need an employee in organization that deals with vulnerabilities in infrastructure on a full-time basis? Since this is similar to what I do for living, I would naturally say that yes, it is necessary. But as person, who makes security automation, I can say that there are some options. ?
What can and can’t Vulnerability Assessment (VA) specialist do?
VA specialist makes recommendations to remove vulnerabilities from your infrastructure using some tools: vulnerability scanners, vulnerability feeds, different news sources. In case of network vulnerabilities, he will most often tell your IT administrators: “Do we use A software with version BBB? As I see some security bulletin says that there is a critical vulnerability in it”. That’s it.
VA specialist by himself usually don’t patch the hosts. Moreover, sometimes he can’t detect the vulnerability, even he has an expansive vulnerability scanner, because some vulnerabilities can only be detected locally during authenticated scanning, and this IS specialist may not have permissions to do it.
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