It’s once again Patch Tuesday, which means the latest security updates from Adobe and Microsoft have arrived. Take a break from your regularly scheduled activities and join us as we review the details of their latest security offerings.

Adobe Patches for March 2022

The Adobe release for March is quite small. This month, Adobe released only three patches addressing six CVEs in Adobe Photoshop, Illustrator, and After Effects. The patch for After Effects is the largest of the three. It fixes four Critical-rated, stacked-based buffer overflows that could result in arbitrary code execution. The fix for Illustrator is also rated Critical. It addresses a single buffer overflow that could lead to arbitrary code execution. Finally, the update for Photoshop fixes a single Important-rated memory leak.

None of the bugs fixed by Adobe this month are listed as publicly known or under active attack at the time of release.

Microsoft Patches for March 2022

For March, Microsoft released 71 new patches addressing CVEs in Microsoft Windows and Windows Components, Azure Site Recovery, Microsoft Defender for Endpoint and IoT, Intune, Edge (Chromium-based), Windows HTML Platforms, Office and Office Components, Skype for Chrome, .NET and Visual Studio, Windows RDP, SMB Server, and Xbox. This is in addition to the 21 CVEs patched by Microsoft Edge (Chromium-based) earlier this month, which brings the March total to 92 CVEs.

Of the 71 CVEs released today, three are rated Critical and 68 are rated Important in severity. A total of seven of these bugs came through the ZDI program. Historically speaking, this is volume is in line with previous March releases. However, the number of Critical-rated patches is again strangely low for this number of bugs. It’s unclear if this low percentage of bugs is just a coincidence or if Microsoft might be evaluating the severity using different calculus than in the past.

None of the bugs are listed as under active exploit this month, while three are listed as publicly known at the time of release. Let’s take a closer look at some of the more interesting updates for this month, starting with one of the bugs listed as publicly known:

-       CVE-2022-21990 – Remote Desktop Client Remote Code Execution Vulnerability
This client-side bug doesn’t have the same punch as server-side related RDP vulnerabilities, but since it’s listed as publicly known, it makes sense to go ahead and treat this as a Critical-rated bug. If an attacker can lure an affected RDP client to connect to their RDP server, the attacker could trigger code execution on the targeted client. Again, this isn’t as severe as BlueKeep or some of the other RDP server bugs, but it definitely shouldn’t be overlooked.

-       CVE-2022-23277 – Microsoft Exchange Server Remote Code Execution Vulnerability
This Critical-rated bug in Exchange Server was reported by long-time ZDI contributor Markus Wulftange. The vulnerability would allow an authenticated attacker to execute their code with elevated privileges through a network call. This is also listed as low complexity with exploitation more likely, so it would not surprise me to see this bug exploited in the wild soon - despite the authentication requirement. Test and deploy this to your Exchange servers quickly.

-       CVE-2022-24508 – Windows SMBv3 Client/Server Remote Code Execution Vulnerability
This bug could allow an attacker to execute code on Windows 10 version 2004 and newer systems. It’s also reminiscent of CVE-2020-0796 from a couple of years ago. Both also list disabling SMBv3 compression as a workaround for SMB servers, but this doesn’t help clients. In 2020, Microsoft noted SMBv3 compression “is not yet used by Windows or Windows Server and disabling SMB Compression has no negative performance impact.” That’s not in the current advisory, so it’s unclear what disabling this feature will have now. Authentication is required here, but since this affected both clients and servers, an attacker could use this for lateral movement within a network. This is another one I would treat as Critical and mitigate quickly.

-       CVE-2022-21967 – Xbox Live Auth Manager for Windows Elevation of Privilege Vulnerability
This appears to be the first security patch impacting Xbox specifically. There was an advisory for an inadvertently disclosed Xbox Live certificate back in 2015, but this seems to be the first security-specific update for the device itself. Microsoft even notes other Windows OSes are not affected by this bug. It’s not clear how an attacker could escalate privileges using this vulnerability, but the Auth Manager component is listed as affected. This service handles interacting with the Xbox Live service. I doubt many enterprises are reliant on Xbox or Xbox Live, but if you are, make sure this patch doesn’t go unnoticed.

Here’s the full list of CVEs released by Microsoft for March 2022:

* Indicates this CVE had previously been released by a 3rd-party and is now being incorporated into Microsoft products.

Looking at the rest of the March release, the 11 CVEs impacting Azure Site Recovery stand out. For those not familiar with it, Site Recovery is a native disaster recovery as a service (DRaaS). This month’s release includes fixes for five elevation of privilege (EoP) and six remote code execution (RCE) bugs in the platform. Considering everything going on in the world, now is a bad time to have issues with your disaster recovery plans. If you’re using this platform, make sure these patches get installed. If you’re not using this platform, take time to review your disaster recovery plans anyway. It couldn’t hurt.

Besides the Exchange bug already mentioned, the Critical-rated fixes in this release both address bugs in HEVC and VP9 video extensions. These updates can be found in the Microsoft Store. If you aren’t connected to the internet or are in an otherwise disconnected environment, you’ll need to manually apply the patch.

Including those already mentioned, there are a total of 28 RCE fixes released today. There are additional updates for the HEVC video extension component. Again, these fixes are obtained through the Microsoft Store. The raw image extension bugs fall into this class as well. There are three fixes for Visio that were reported by kdot through this ZDI program. These bugs include a type confusion, an untrusted pointer deref, and an Out-Of-Bounds (OOB) Write. In each case, a user must open a specially crafted Visio file to be impacted. One of the other publicly known bugs is an RCE in .NET and Visual Studio. There’s scant information about this bug, but if you are developing apps in .NET or Visual Studio, review it carefully. Since RPC bugs are never out of fashion, there’s a fix for event tracing that could result in code execution through a specially crafted RPC connection. There are several caveats to this one that lower the severity, but don’t remove the risk completely.

Rounding out the RCE bugs is one submitted by an anonymous researcher through the ZDI program impacts Microsoft Defender for IoT. The vulnerability exists within the password change mechanism. It results from the lack of proper validation of a user-supplied string before using it to execute a system call. Defender for IoT also receives a patch for an EoP bug found by ZDI Vulnerability Researcher Simon Zuckerbraun. This bug also occurs within the password change mechanism, but here, the bug is caused by the lack of proper validation of a user-supplied string before using it to execute a system call. An attacker can leverage this vulnerability to escalate privileges and execute arbitrary code in the context of root.

Moving on to the other EoP cases, most would require an attacker to log on to a system and run a specially crafted program. Several of these fixes note that the vulnerability is the result of a race condition, making exploitation somewhat unreliable. There are some interesting components receiving fixes for privilege escalations this month, including the FAT file system, the Fax and Scan Service, and the CD-ROM driver. It’s almost retro. Another interesting component is the Windows PDEV, which is a logical representation of a physical device characterized by the type of hardware, logical address, and surfaces that can be supported. ZDI Vulnerability Researcher Lucas Leong reported a Use-After-Free (UAF) bug in the handling of PDEV objects. An attacker could use this to escalate privileges and execute arbitrary code in the context of SYSTEM.

Six of this month’s fixes address information disclosure bugs. For the most part, these only result in leaks consisting of unspecified memory contents. The lone exception is the bug impacting the Skype for Chrome extension. This vulnerability could inadvertently disclose the Skype ID of a target. An attacker could gain access to that ID they could match it within Skype to a name and Avatar of the target user. If you’re using Skype for Chrome, you’ll need to get the update through the Chrome Web Store.

There are four updates to address DoS bugs in this release, and two stand out over the others. The first is a DoS in Hyper-V, which is always inconvenient if you happen to be one of the other guest OSes on that Hyper-V server. The other is a vulnerability in the Point-to-Point Tunneling (PPTP) protocol, which is used in the implementation of virtual private networks (VPN) that allow people to extend their private networks over the Internet via “tunnels”. There are no details about this bug given, but anything that could take down a VPN is unwelcome – especially since so many of us rely on VPNs to work from home (or wherever).

Three different components receive fixes for security feature bypasses (SFB) in this month’s release. The first continues the retro theme by fixing bugs in the Windows HTML platforms, including Internet Explorer and Edge (HTML-Based). Microsoft does not indicate which security feature is bypassed, but considering how pervasive MSHTML continues to be, patching is certainly recommended. Word receives a fix for an SFB bug that could allow specific protections to be bypassed in Protected View. This could potentially result in a user opening a malicious document but not receiving the intended warning dialogs. The final SFB fix applies to the Intune Portal for iOS. An attacker could use this vulnerability to bypass the Intune policy file save location and presumably load their own policy instead.

This month’s release includes three updates for spoofing bugs. The Exchange spoofing bug could allow an authenticated attacker to view file content on the affected server. Microsoft provides little information about the spoofing bugs in Defender Endpoint and Visual Studio other than to say the Defender bug requires knowledge of the target environment and the Visual Studio bug requires a user to open a file.

We wrap up this month’s release with an odd tampering bug in Microsoft Word. Microsoft gives no information on how the vulnerability can be exploited, but they do indicate information from the victim can be sent to the attacker, and that the Preview Pane is an attack vector. It sounds like a specially crafted Word doc can send potentially sensitive information to an attacker when the document is opened or viewed in the Preview Pane. Office for Mac users are out of luck as well, as the patches for Microsoft Office 2019 for Mac and Microsoft Office LTSC for Mac 2021 are not available yet. It will be interesting to see if additional information is released about this bug in the future.

No new advisories were released this month. The latest servicing stack updates can be found in the revised ADV990001.

Looking Ahead

The next Patch Tuesday falls on April 12, and we’ll return with details and patch analysis then. Until then, stay safe, happy patching, and may all your reboots be smooth and clean!