Windows TDX elevation of privilege vulnerability: June 13, 2017

Summary

An elevation of privilege vulnerability exists when tdx.sys fails to check the length of a buffer prior to copying memory to the buffer. To exploit the vulnerability, in a local attack scenario, an attacker could run a specially crafted application to elevate the attacker’s privilege level. An attacker who successfully exploited this vulnerability could run processes in an elevated context. However, an attacker must first gain access to the local system with the ability to execute a malicious application in order to exploit this vulnerability.

The security update addresses the vulnerability by changing how tdx.sys validates buffer length.

To learn more about the vulnerability, go to CVE-2017-0296.

More Information

Important

• 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 Windows Update: FAQ.

Method 2: Microsoft Update Catalog

To get the stand-alone package for this update, go to the Microsoft Update Catalog website.

Deployment information

For deployment details for this security update, go to the following article in the Microsoft Knowledge Base:
Security update deployment information: June 13, 2017

More Information

File informationThe English (United States) version of this software update installs files that have the attributes that are listed in the following tables.

Windows Server 2008 file information

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

How to obtain help and support for this security update

Help for installing updates: Windows Update: FAQ

Security solutions for IT professionals: TechNet Security Support and Troubleshooting

Help for protecting your Windows-based computer from viruses and malware: Microsoft Secure

Local support according to your country: International Support

File information

File hash information

File name	SHA1 hash	SHA256 hash
Windows6.0-KB4021923-ia64.msu	33AEE52FAB1B7081827FBA801CE1CEF5DD62426C	5B528987E4EF0261AE10CDB56FABA820F546B6DEF09AFA3630DB927BFA9CDEE2
Windows6.0-KB4021923-x64.msu	52F69212BFD6CDB74CB32AC52D1CD557D5D826C0	929E6D4720529D6BD5689BE21280547F5D5F92660F55478D3F9F5DEED7F56CF2

For all supported ia64-based versions

File name	File version	File size	Date	Time	Platform
Tdx.sys	6.0.6002.19787	229,376	14-May-2017	17:10	IA-64
Tdx.sys	6.0.6002.24105	229,376	14-May-2017	17:00	IA-64

For all supported x64-based versions

File name	File version	File size	Date	Time	Platform
Tdx.sys	6.0.6002.19787	94,720	14-May-2017	17:22	x64
Tdx.sys	6.0.6002.24105	94,720	14-May-2017	18:53	x64