October 2023: back to Positive Technologies, Vulristics updates, Linux Patch Wednesday, Microsoft Patch Tuesday, PhysTech VM lecture. 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.
Joint Advisory AA22-279A and Vulristics. 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.
Security News: Exchange ProxyShell, Zoom RCE, Citrix Canceled PT Acknowledgments, Cisco No Patch Router RCEs. Hello everyone! This is a new episode with my comments on the latest Information Security news.
Exchange ProxyShell
I want to start with something about attacks on Exchange. ProxyShell is in the news, the LockFile ransomware compromised more than 2000 servers. On the other hand, there is basically nothing to say here.
ProxyShell is the name for 3 vulnerabilities. The bulletins for Remote Code Execution CVE-2021-34473 and Server Elevation of Privilege CVE-2021-34523 were released on July 13, but were fixed by April Patch Tuesday patches. Yes, it happens sometimes. The bulletin for Security Feature Bypass CVE-2021-31207 was released on May 11. Users had 4 months to install the updates. Interestingly, 2 out of 3 vulnerabilities have the property “Less likely to be exploited”. As you can see, it’s pretty useless.
Last Week’s Security news: Serious Sam in Metasploit, PetitPotam, Zimbra Hijack, Joint Advisory TOP30 CVEs. 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.”
This is my personal blog. The opinions expressed here are my own and not of my employer. All product names, logos, and brands are property of their respective owners. All company, product and service names used here for identification purposes only. Use of these names, logos, and brands does not imply endorsement. You can freely use materials of this site, but it would be nice if you place a link on https://avleonov.com and send message about it at me@avleonov.com or contact me any other way.
