Improvements and fixes
This security update includes quality improvements. No new operating system features are being introduced in this update. Key changes include:
Provides protections against an additional subclass of speculative execution side-channel vulnerability known as Speculative Store Bypass (CVE-2018-3639) for AMD-based computers. These protections aren't enabled by default. For Windows Server guidance, follow the instructions in KB4072698. Use this guidance document to enable mitigations for Speculative Store Bypass (CVE-2018-3639). Additionally, use the mitigations that have already been released for Spectre Variant 2 (CVE-2017-5715) and Meltdown (CVE-2017-5754).
Addresses an issue that affects PowerShell remoting loop back using non-administrator accounts. For more details, see Windows Security change affecting PowerShell.
Security updates to Windows Kernel, Windows Storage and Filesystems, Windows Wireless Networking, and the Microsoft JET Database Engine.
For more information about the resolved security vulnerabilities, please refer to the Security Update Guide.
Known issues in this update
Local users who are part of the local “Administrators“ group may not be able to remotely access shares on Windows Server 2008 SP2 machines after installing the January 8th, 2019 security updates. This does not affect domain accounts in the local "Administrators" group.
This issue is resolved in KB4487354.
Applications that use a Microsoft Jet database with the Microsoft Access 97 file format may fail to open if the database has column names greater than 32 characters. The database will fail to open with the error, “Unrecognized Database Format”.
This issue is resolved in KB4487019.
After installing this update, virtual machines (VM) may fail to restore successfully if the VM has been saved and restored once before. The error message is, “Failed to restore the virtual machine state: Cannot restore this virtual machine because the saved state data cannot be read. Delete the saved state data and then try to start the virtual machine. (0xC0370027).”
This affects AMD Bulldozer Family 15h, AMD Jaguar Family 16h, and AMD Puma Family 16h (second generation) microarchitectures.
This issue is resolved in KB4490514.
How to get this update
This update is now available for installation through WSUS. To get the stand-alone package for this update, go to the Microsoft Update Catalog website.
For a list of the files that are provided in this update, download the file information for update 4480957.