Applies ToWindows Server 2012 R2 Datacenter Windows Server 2012 R2 Standard Windows Server 2012 R2 Essentials Windows Server 2012 R2 Foundation Windows 8.1 Enterprise Windows 8.1 Pro Windows 8.1

Summary

This security update resolves a vulnerability in Windows that could allow security feature bypass if an attacker runs a specially crafted application that could cause Windows Hyper-V to apply access control list (ACL) configuration settings incorrectly. Customers who do not have the Hyper-V role enabled are not affected.To learn more about the vulnerability, see Microsoft Security Bulletin MS15-105.

More Information

Important

  • All future security and nonsecurity updates for Windows 8.1 and Windows Server 2012 R2 require update 2919355 to be installed. We recommend that you install update 2919355 on your Windows 8.1-based or Windows Server 2012 R2-based computer so that you receive future updates.

  • If you install a language pack after you install this update, you must reinstall this update. Therefore, we recommend that you install any language packs that you need before you install this update. For more information, see Add language packs to Windows.

How to obtain and install the update

Method 1: Windows Update

This update is available through Windows Update. When you turn on automatic updating, this update will be downloaded and installed automatically. For more information about how to turn on automatic updating, see Get security updates automatically.

You can obtain the stand-alone update package through the Microsoft Download Center. Follow the installation instructions on the download page to install the update.Click the download link in Microsoft Security Bulletin MS15-105 that corresponds to the version of Windows that you are running.

More Information

The English (United States) version of this software update installs files that have the attributes that are listed in the following tables. The dates and times for these files are listed in Coordinated Universal Time (UTC). The dates and times for these files on your local computer are displayed in your local time and with your current daylight saving time (DST) bias. Additionally, the dates and times may change when you perform certain operations on the files.

Windows 8.1 and Windows Server 2012 R2 file information

  • The files that apply to a specific product, milestone (RTM,SPn), and service branch (LDR, GDR) can be identified by examining the file version numbers as shown in the following table:

    Version

    Product

    Milestone

    Service branch

    6.3.920 0.16 xxx

    Windows 8.1 and Windows Server 2012 R2

    RTM

    GDR

  • GDR service branches contain only those fixes that are widely released to address widespread, critical issues. LDR service branches contain hotfixes in addition to widely released fixes.

Note The MANIFEST files (.manifest) and MUM files (.mum) that are installed are not listed.

For all supported x64-based versions of Windows 8.1 and Windows Server 2012 R2

File name

File version

File size

Date

Time

Platform

Vmsif.dll

6.3.9600.17396

65,024

08-Oct-2014

05:53

x64

Vmsnetsetupplugin.dll

6.3.9600.17396

33,792

08-Oct-2014

06:07

x64

Vmswitch.sys

6.3.9600.18005

689,152

05-Aug-2015

14:14

x64

Vmsif.dll

6.3.9600.17396

65,024

08-Oct-2014

05:53

x64

Vmsntfy.dll

6.3.9600.17396

91,648

08-Oct-2014

06:54

x64

Vmswitch.sys

6.3.9600.18005

689,152

05-Aug-2015

14:14

x64

Vmsif.dll

6.3.9600.17396

65,024

08-Oct-2014

05:53

x64

Vmsntfy.dll

6.3.9600.17396

91,648

08-Oct-2014

06:54

x64

Vmswitch.sys

6.3.9600.18005

689,152

05-Aug-2015

14:14

x64

Vmsif.dll

6.3.9600.17396

65,024

08-Oct-2014

05:53

x64

Vmsntfy.dll

6.3.9600.17396

91,648

08-Oct-2014

06:54

x64

Vmswitch.sys

6.3.9600.18005

689,152

05-Aug-2015

14:14

x64

Help for installing updates: Support for Microsoft UpdateSecurity solutions for IT professionals: TechNet Security Troubleshooting and SupportHelp for protecting your Windows-based computer from viruses and malware: Virus Solution and Security CenterLocal support according to your country: International Support

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