Windows 11 January 2025 Update KB5050009: Key Security Enhancements

The time has come yet again for an important Windows 11 security update, and this one launches us into a new year with notable enhancements geared toward protecting your PC. Microsoft has officially rolled out the January 14, 2025—KB5050009 (OS Build 26100.2894) update. Whether you're a power user, an IT administrator, or just someone running Windows 11 on your home machine, here’s everything you need to know about this update. Spoiler alert: it’s not just another patch for your OS; it’s got some weight to it.

---

What's New in the January 2025 Update (KB5050009)?​

This update focuses on improving security while knocking out known vulnerabilities, particularly focusing on Bring Your Own Vulnerable Driver (BYOVD) exploits. BYOVD is a sneaky type of malware attack where malicious actors leverage legitimate but vulnerable drivers to bypass your system's defenses. With the KB5050009 update, Microsoft extends its Driver Blocklist file (DriverSiPolicy.p7b) to counter these potential threats more effectively.
If security is a fortress and BYOVD is a Trojan horse, this update throws up an extra layer of reinforced walls.

Highlights of the Update:​

1. Security-First Approach
   This update patches a variety of vulnerabilities, targeting areas where Windows 11 systems have been deemed most at risk.
2. Carryover Improvements from December 2024 (KB5048667 Update)
   If you missed the previous update, some key features from late 2024 improvements make their way into this release. You'll now only get the incremental changes if KB5048667 was already installed on your device.
3. Servicing Stack Update (SSU)
   A separate package (KB5050387) ensures your system's update mechanisms remain robust. This means smoother future updates with fewer hiccups. Think of it as giving your car a professional tune-up before a big road trip.

---

Key Fixes, Issues, and Known Limitations​

Every patch has its quirks, and the KB5050009 update is no exception. Here’s a closer look at what’s been enhanced, along with ongoing issues that Microsoft is actively addressing.

Key Fix​

• Driver Block Enhancements:
  Expanded protection against malware using vulnerable drivers to exploit system-level weaknesses in Windows’ kernel. Vulnerable drivers pose significant risks, as they operate at a low level in the system, making them a common target for hackers.

---

Known Issues With This Update​

1. Roblox on ARM Devices:
   Are you a Roblox player using an ARM-based Windows device? Cue the disappointment. Users have found themselves unable to download or play Roblox via the Microsoft Store after applying the update. Temporary answer? Get the game directly from Roblox.com and bypass the store.
2. OpenSSH Service Failures:
   If you’re relying on the OpenSSH service for secure shell connections, this issue might hit close to home. Following the October 2024 security update, some customers reported that OpenSSH services fail to start. Good news though: A temporary PowerShell-based workaround is available. By updating permissions (ACLs) on the affected directories, you can restore functionality. Manual intervention might be a hassle, but it’s a lifesaver until Microsoft releases a permanent fix.
   • Path Affected: C:\ProgramData\ssh
   • Use the provided ACL PowerShell commands (remember to run them as an Administrator).
3. Citrix Session Recording Agent (SRA) Compatibility Glitch:
   If your organization uses Citrix’s latest SRA Version 2411, don’t be shocked if the update installation fails. Devices may revert the changes during reboot after applying the update. Citrix has already published temporary fixes for those affected, but Microsoft and Citrix are actively tackling this issue to resolve it in future patches.

---

How to Install the Update​

Ready to install KB5050009? Microsoft has packaged everything conveniently for deployment via several methods. Below is a quick guide to help.

Step-by-Step Instructions:​

1. For Home Users: Automatic Updates
   • Navigate to Settings > Windows Update to check and install the latest version. The update is available by default unless deferred manually.
2. For Enterprise or IT Professionals:
   Use the MICROSOFT UPDATE CATALOG to download standalone update files. You can then use DISM.exe to deploy the update on both live systems and installation media.
   • Command:
     
     Code:

     bash
     
          DISM /Online /Add-Package /PackagePath:c:\packages\Windows11.0-KB5050009-x64.msu

3. Via WSUS (Windows Server Update Services):
   Configure the following:
   • Product: Windows 11
   • Classification: Security Updates
4. Update Installation Media:
   • Run commands to inject the KB package directly into your Windows image. For example:
     
     Code:

     bash
     
          Add-WindowsPackage -Path "C:\offline" -PackagePath "Windows11.0-KB5050009-x64.msu"

5. Rollbacks and Troubleshooting:
   While the combined SSU and LCU package can be installed as one, removing the LCU later will not touch the SSU. To roll back an LCU update:
   
   Code:

   bash
   
      DISM /Online /Remove-Package

---

Understanding the Broader Implications​

1. Focus on BYOVD Mitigation: Why This Matters​

BYOVD is a growing cybersecurity concern. The problem lies with legitimate drivers, which, upon exploitation, subvert Windows' native security measures like Driver Signature Enforcement (DSE) and HyperVisor-enforced Code Integrity (HVCI). By continually expanding the Vulnerable Driver Blocklist, Microsoft strengthens defenses against seemingly "legitimate" yet dangerous components.

---

2. Servicing Stack Updates (SSUs): Stability, Simplified​

If you've ever found a Windows Update stuck mid-installation, chances are weak servicing stacks are to blame. SSUs ensure the system's ability to apply future updates reliably. Microsoft’s consolidation of package releases means fewer moving parts to mess up your system integrity.

---

3. Microsoft Store vs. Third-Party Software Updates​

Interestingly, these updates don't include updates for Microsoft Store apps. Especially for IT admins, keeping Store apps in sync with corporate security standards is a growing challenge. Microsoft suggests using Configuration Manager for enterprises and built-in update management tools for home users.

---

Summary: To Update or Not to Update?​

Without question, the KB5050009 (OS Build 26100.2894) update is a vital step forward, especially for security-conscious users and enterprises alike. With a heavy focus on neutralizing kernel-level exploits, expanding its BYOVD defenses, and stabilizing the servicing stack, this patch strengthens what was already a solid Windows 11 foundation.
While minor issues like the OpenSSH bug might cause hiccups, the associated workarounds are manageable, especially for those equipped with IT know-how. And with Microsoft's continued efforts on resolving such issues promptly, it's evident there’s no better time to keep your system patched and secure.
Pro Tip: Always back up critical files ahead of updates, particularly for those running complex enterprise networks or custom configurations with Citrix components.
Have you encountered any of these issues? What are your thoughts on the new Driver Blocklist enhancements? Let’s dive into the comments and discuss how this impacts you!

---

Source: Microsoft Announcements The January 2025 Windows security update is now available