Tag Archives: Exchange

Security News: Microsoft Patch Tuesday October 2021, Autodiscover, MysterySnail, Exchange, DNS, Apache, HAProxy, VMware vCenter, Moodle

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.

Microsoft Patch Tuesday for October 2021

74 vulnerabilities: 1 Critical, 30 High, 43 Medium.

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.

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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.

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Last Week’s Security News: Black Hat Pwnie Awards, iPhone Checks Photos, Evil Windows Print Server, Cisco VPN Routers Takeovers

Hello everyone! Last Week’s Security News, August 1 – August 8.

Black Hat Pwnie Awards

Last week was more quiet than normal with Black Hat USA and DEF CON security conferences. I would like to start with the Pwnie Awards, which are held annually at Black Hat. It’s like an Oscar or Tony in the information security world. Pwnie Awards recognizes both excellence and incompetence. And, in general, is a very respectable, adequate and fun event.

There were 10 nominations. I will note a few.

  • Firstly 2 nominations, which were received by the guys from Qualys.
    Best Privilege Escalation Bug: Baron Samedit, a 10-year-old exploit in sudo.
    Most Under-Hyped Research: 21Nails, 21 vulnerabilities in Exim, the Internet’s most popular mail server.
  • Best Server-Side Bug: Orange Tsai, for his Microsoft Exchange Server ProxyLogon attack surface discoveries.
  • Most Epic Fail: Microsoft, for their failure to fix PrintNightmare.
  • Best Song: The Ransomware Song by Forrest Brazeal
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Vulristics Microsoft Patch Tuesday July 2021: Zero-days EoP in Kernel and RCE in Scripting Engine, RCEs in Kernel, DNS Server, Exchange and Hyper-V

Hello everyone! For the past 9 months, I’ve been doing Microsoft Patch Tuesday reviews quarterly. Now I think it would be better to review the July Patch Tuesday while the topic is still fresh. And that will save us some time in the next Last Week’s Security news episode. So, July Patch Tuesday, 116 vulnerabilities.

The 2 most critical are the Windows Kernel Elevation of Privilege Vulnerabilities (CVE-2021-31979, CVE-2021-33771). These vulnerabilities are critical because they are used in real attacks according to Microsoft’s Threat Intelligence Center and Security Response Center. Tenable: “A local, authenticated attacker could exploit these vulnerabilities to run processes with elevated permissions. Similar zero-day vulnerabilities were patched in April 2020, which were observed under active exploitation by Google Project Zero.”

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Vulristics: Microsoft Patch Tuesdays Q2 2021

Hello everyone! Let’s now talk about Microsoft Patch Tuesday vulnerabilities for the second quarter of 2021. April, May and June. Not the most exciting topic, I agree. I am surprised that someone is reading or watching this. For me personally, this is a kind of tradition. Plus this is an opportunity to try Vulristics in action and find possible problems. It is also interesting to see what VM vendors considered critical back then and what actually became critical. I will try to keep this video short.

First of all, let’s take a look at the vulnerabilities from the April Patch Tuesday. 108 vulnerabilities, 55 of them are RCEs. Half of these RCEs (27) are weird RPC vulnerabilities. “Researcher who reported these bugs certainly found quite the attack surface”. The most critical vulnerability is RCE in Exchange (CVE-2021-28480). This is not ProxyLogon, this is another vulnerability. ProxyLogon was in March. And this vulnerability is simply related to ProxyLogon, so it is believed that it is exploited in the wild as well. In the second place this Win32k Elevation of Privilege (CVE-2021-28310). It is clearly mentioned in several sources as being used in real attacks. “Bugs of this nature are typically combined with other bugs, such as a browser bug or PDF exploit, to take over a system”. And the only vulnerability with a public exploit is the Azure DevOps Server Spoofing (CVE-2021-28459). Previously known as Team Foundation Server (​TFS), Azure DevOps Server is a set of collaborative software development tools. It is hosted on-premises. Therefore, this vulnerability can be useful for attackers.

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Vulristics: Microsoft Patch Tuesdays Q1 2021

Hello everyone! It has been 3 months since my last review of Microsoft vulnerabilities for Q4 2020. In this episode I want to review the Microsoft vulnerabilities for the first quarter of 2021. There will be 4 parts: January, February, March and the vulnerabilities that were released between the Patch Tuesdays.

I will be using the reports that I created with my Vulristics tool. This time I’ll try to make the episodes shorter. I will describe only the most critical vulnerabilities. Links to the full reports are at the bottom of the blog post.

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Vulristics Vulnerability Score, Automated Data Collection and Microsoft Patch Tuesdays Q4 2020

In this episode I would like to make a status update of my Vulristics project. For those who don’t know, in this project I retrieve publicly available vulnerability data and analyze it to better understand the severity of these vulnerabilities and better prioritize them. Currently, it is mainly about Microsoft Patch Tuesday vulnerabilities, but I have plans to go further. Also in this episode I want to demonstrate the new Vulristics features on Microsoft Patch Tuesday reports for October, November and December 2020.

Vulristics Vulnerability Scores, automated data collection and Microsoft Patch Tuesday Q4 2020

Patch Tuesdays Automated Data Collection

First of all, I dealt with the annoying collecting of the data for Microsoft Patch Tuesdays reports. Previously it took pretty long time. I had to go to Microsoft website and search for CVE IDs. After that, I had to get the comments from various Vulnerability Management vendors and researchers blogs (Tenable, Qualys, Rapid7, ZDI). I wanted this to be as much automated as possible. I have added some code to make CVE search requests on the Microsoft website for a date range (including the second Tuesday of the month). I also figured out how to make searches on the Vulnerability Management vendors blogs. So, now to get a Microsoft Patch Tuesday report it’s only necessary to set the year and month.

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