Patch Office and Windows now to resolve two zero-days

Microsoft has resolved 80 new CVEs this month along with 4 earlier CVEs, bringing the variety of safety points addressed on this month’s Patch Tuesday launch to 84. Sadly, we’ve two zero-day flaws in Outlook (CVE-2023-23397) and Home windows (CVE-2023-24880) that require a “Patch Now” launch requirement for each Home windows and Microsoft Workplace updates. Because it was final month, there have been no additional updates for Microsoft Trade Server or Adobe Reader. This month the group at Software Readiness has supplied a useful infographic that outlines the dangers related to every of the updates for this cycle.Identified issuesEach month, Microsoft features a checklist of recognized points that relate to the working system and platforms included within the replace cycle.
KB5022842: After putting in KB5022842 on Home windows Server 2022 with Safe Boot enabled and rebooting twice, the VMware VM didn’t boot utilizing the brand new bootmgr. This challenge continues to be into account by Microsoft. After putting in this replace, WPF apps might have a change in conduct.
After putting in this month’s Home windows replace on visitor digital machines (VMs) operating Home windows Server 2022 on some variations of VMware ESXi, Home windows Server 2022 won’t begin.
Microsoft continues to be engaged on a community efficiency challenge with Home windows 11 22H2. Giant (multi-gigabyte) community file transfers (and doubtlessly equally giant native transfers) are affected. This challenge ought to primarily have an effect on IT directors.Main revisionsMicrosoft printed 4 main revisions this month masking:
VE-2023-2156: Microsoft SQL Server Integration Service (VS extension) Distant Code Execution Vulnerability.
CVE-2022-41099: Title: BitLocker Safety Function Bypass Vulnerability.
CVE-2023-21716: Microsoft Phrase Distant Code Execution Vulnerability.
CVE-2023-21808 .NET and Visible Studio Distant Code Execution Vulnerability.
All of those revisions have been resulting from documentation and expanded affected software program updates. No additional motion is required.Mitigations and workaroundsMicrosoft printed the next vulnerability associated mitigations for this month’s launch:
CVE-2023-23392: HTTP Protocol Stack Distant Code Execution Vulnerability. A prerequisite for a Home windows 2022 server to be susceptible to this safety challenge is that the community binding has HTTP/3 enabled and the server makes use of buffered I/O. Enabling HTTP/3 is mentioned right here: Enabling HTTP/3 help on Home windows Server 2022.
CVE-2023-23397: Microsoft Outlook Elevation of Privilege Vulnerability. Microsoft has printed two mitigations for this severe safety challenge:

Add customers to the Protected Customers Safety Group, which prevents the usage of NTLM as an authentication mechanism.
Block TCP 445/SMB outbound out of your community by utilizing a fringe firewall, an area firewall, and by way of your VPN settings.

Testing steering Every month, the group at Readiness analyzes the Patch Tuesday updates and gives detailed, actionable testing steering; that steering is predicated on assessing a big utility portfolio and an in depth evaluation of the Microsoft patches and their potential impression on the Home windows platforms and utility installations.Given the massive variety of adjustments included this month, I’ve damaged down the testing situations into high-risk and standard-risk teams.Excessive riskMicrosoft printed a number of excessive danger adjustments within the March replace. Whereas they might not result in performance adjustments, the testing profile for every replace must be obligatory:
Microsoft has up to date how DCOM responds to distant requests as a part of the latest hardening effort. This course of has been below means since June 2021 (Part 1), with an replace in June 2022 (Part 2) and now this month with all adjustments  applied as obligatory. DCOM is a core Home windows element used for speaking between providers or processes. Microsoft has suggested that this (and full deployment of previous suggestions) will trigger application-level compatibility points. The corporate has supplied some help on what’s altering and methods to mitigate any compatibility points because of these latest obligatory settings.
A significant change to the core system file Win32kfull.sys has been included this month as two features (DrvPlgBlt and nf-wingdi-plgblt) have been up to date. Microsoft has suggested there are not any practical adjustments to those features. Testing purposes that rely upon these features can be important earlier than a full deployment of this month’s updates.
These situations require vital application-level testing earlier than common deployment.
Bluetooth: Attempt including and eradicating new Bluetooth gadgets. Stressing Bluetooth community gadgets could be extremely suggested.
Home windows Community stack (TCPIP.SYS): Fundamental net browsing, “regular” file transfers and video streaming must be adequate to check the adjustments to the Home windows networking stack.
Hyper-V: Attempt testing each Gen1 and Gen2 digital machines (VM’s). Each sorts of machines ought to begin, cease, shut down, pause, and resume efficiently.
Along with these adjustments, Microsoft up to date a key reminiscence operate (D3DKMTCreateDCFromMemory) that impacts two key system-level Home windows drivers (win32kbase.sys and win32kfull.sys). Sadly, in previous updates to those drivers, some customers have generated BSOD SYSTEM_SERVICE_EXCEPTION errors. Microsoft has posted info on methods to handle these points. Hopefully you do not have to resolve these sorts of points this month.Home windows lifecycle updateThis part comprises essential adjustments to servicing (and most safety updates) to Home windows desktop and server platforms over the following few months:
Home windows 10 Enterprise (and Training), Model 20H2 and Home windows 10 IoT Enterprise, and Home windows Model 20H2 will attain an finish of servicing date on Could 9, 2023.
Every month, we break down the replace cycle into product households (as outlined by Microsoft) with the next fundamental groupings:
Browsers (Microsoft IE and Edge).
Microsoft Home windows (each desktop and server).
Microsoft Workplace.
Microsoft Trade Server.
Microsoft Growth platforms (ASP.NET Core, .NET Core and Chakra Core).
Adobe (retired???, possibly subsequent 12 months).
BrowsersThere have been 22 updates for March (none rated important), with 21 included within the Google launch channel and one (CVE-2023-24892) from Microsoft. All these updates are easy-to-deploy updates with marginal to low deployment danger. You could find Microsoft’s model of these launch notes right here and the Google Desktop channel launch notes right here. Add these updates to your customary patch launch schedule. WindowsMicrosoft launched 10 important updates and 48 patches rated as essential to the Home windows platform that cowl the next key elements:
Microsoft Printer Postscript Drivers.
Home windows Bluetooth Service.
Home windows Win32K and Core Graphics elements (GDI).
Home windows HTTP Protocol Stack and PPPoE.
Apart from the latest change to DCOM authentication (see DCOM hardening) most of this month’s updates have a really low danger profile. Now we have a minor replace to a printing subsystem (Postscript 6) and different tweaks to community dealing with, storage, and graphics elements. Sadly, we’ve an actual zero-day challenge with Home windows (CVE-2023-24880) SmartScreen (aka Home windows Defender) with stories of each exploitation and a public disclosure. In consequence, add these Home windows updates to your “Patch Now” launch schedule.Microsoft OfficeMicrosoft launched 11 updates to the Microsoft Workplace platform with one rated as (tremendous) important and the remaining updates rated essential and affecting simply Excel and SharePoint. Sadly, the Microsoft Outlook replace (CVE-2023-23397) must be patched instantly. I’ve included suggestions supplied by Microsoft in our mitigations part above which embody including customers to the next safety group and blocking ports 445/SMB in your community. Given the low danger of breaking different apps and the benefit of deployment of this patch, I’ve one other concept: add these Workplace updates to your “Patch Now” launch schedule.Microsoft Trade ServerNo Microsoft Trade updates required this month. That stated, there’s a significantly worrying challenge with Microsoft Outlook (CVE-2023-23397) that can be sufficient for any mail administrator to deal with this month.Microsoft improvement platformsThis is a really mild patch cycle for Microsoft improvement platforms with simply 4 updates to Visible Studio (GitHub extensions) this month. All these updates are rated as essential by Microsoft and have a really low deployment danger profile. Add these updates to your customary developer launch schedule. Adobe Reader (nonetheless right here, however simply not this month)We could also be seeing a pattern right here as Adobe has not launched any updates for Adobe Reader. It’s also fascinating that that is the primary month in 9 that Microsoft has not launched any important updates to its XPS, PDF or printing system. So, no obligatory printer testing is required.

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