Surface guidance to protect against speculative execution side-channel vulnerabilities

Applies to: SurfaceSurface BookSurface Studio 1 More

Introduction

Since January 2018, the Surface team has been publishing firmware updates for a new class of hardware vulnerabilities that involve speculative execution side channels. The Surface team has not received any information to indicate that these vulnerabilities have been used to attack customers currently, and the team continues to work closely with the Windows team and industry partners to protect customers. To get all available protection, both firmware and Windows system updates are required.

Summary

Vulnerabilities Announced in May 2019

The Surface team is aware of new speculative execution side-channel attack variants that also affect Surface products. Mitigation of those vulnerabilities requires an operating system update and a Surface UEFI update that includes new microcode. For more information about the vulnerabilities and mitigations, see the following security advisory:

Microsoft Security Advisory ADV190013

We are working together with our partners to provide updates to the following Surface products as soon as we can make sure that the updates meet our quality requirements:

Surface 3 - July 11, 2019, update
Surface Pro 3 - July 11, 2019, update
Surface Pro 4 - June 27, 2019, update
Surface Book - June 27, 2019, update
Surface Studio - July 11, 2019, update
Surface Pro (5^th Gen) - June 27, 2019, update
Surface Laptop - June 27, 2019, update
Surface Book 2 - June 27, 2019, update
Surface Pro 6 - June 27, 2019, update
Surface Laptop 2 - June 27, 2019, update
Surface Studio 2- July 31, 2019, Update
Surface GO WiFi
Surface GO LTE

In addition to the new microcode, a new UEFI setting that is known as “Simultaneous Multi-Threading (SMT)” will be available when the UEFI update is installed. This setting allows a user to disable Hyper-Threading.

Notes

If you decide to disable Hyper-Threading, we recommend that you use the new SMT UEFI setting.
Disabling SMT provides additional protection against these new vulnerabilities and the L1 Terminal Fault attack that was announced earlier. However, this method also affects the performance of the device.
Surface 3 and Surface Studio with Intel Core i5 do not have SMT. Therefore, those devices do not have this new setting.
The Microsoft Surface Enterprise Management Mode (SEMM) UEFI configurator tool version 2.43.139 or later supports the new SMT setting. The tools can be downloaded from this webpage. Download the following required tools:
- SurfaceUEFI_Configurator_v2.43.139.0.msi
- SurfaceUEFI_Manager_v2.43.139.0.msi

References

CVE-2018-12126

CVE-2018-12127

CVE-2018-12130

CVE-2019-11091

Vulnerability Announced in August 2018

The Surface team is aware of a new speculative execution side-channel attack called L1 Terminal Fault (L1TF) and assigned CVE-2018-3620 (OS and SMM) and CVE-2018-3646 (VMM). Affected Surface products are the same as in the “Vulnerabilities Announced in May 2018” section of this article. The microcode updates that mitigate the May 2018 findings also mitigate L1TF (CVE-2018-3646). For more information about the vulnerability and mitigations, see the following security advisory:

Microsoft Security Advisory ADV180018

The security advisory proposes that customers who are using Virtualization Based Security (VBS), which includes security features such as Credential Guard and Device Guard, should consider disabling Hyper-Threading in order to fully eliminate the risk from L1TF. Customers cannot currently disable Hyper-Threading on their Surface devices. By default, VBS features are disabled on Surface devices. The Surface team is investigating options to allow disabling Hyper-Threading.

References

Vulnerabilities Announced in May 2018

The Surface team has become aware of new speculative execution side-channel attack variants that also affect Surface products. Mitigation of those vulnerabilities requires UEFI updates that use new microcode. For more information about the vulnerabilities and mitigations, see the following security advisories:

We are working together with our partners to provide updates to the following Surface products as soon as we can make sure that the updates meet our quality requirements:

Surface Book 2 - August 1, 2018 update
Surface Book - August 21, 2018 update
Surface Laptop - July 25, 2018 update
Surface Studio - October 1, 2018 update
Surface Pro 4 - July 25, 2018 update
Surface Pro 3 - August 7, 2018 update
Surface Pro Model 1796 and Surface Pro with Advanced LTE Model 1807 - July 26, 2018 update

References

Vulnerabilities Announced in January 2018

The Surface team is aware of the publicly disclosed class of vulnerabilities that involve speculative execution side channels (known as Spectre and Meltdown) that affect many modern processors and operating systems, including Intel, AMD, and ARM. For more information about the vulnerabilities and mitigations, see the following security advisory:

Microsoft Security Advisory ADV180002

For more information about Windows software updates, see the following Knowledge Base articles:

4073757 Protect your Windows devices against Spectre and Meltdown vulnerabilities
4073119 Windows Client Guidance for IT Pros to protect against speculative execution side-channel vulnerabilities

In addition to installing the January 3 Windows Operating System Security Updates, Surface has released UEFI updates through Windows Update and the Download Center for the following devices:

Surface Book 2 - (Update history)
Surface Book - (Update history)
Surface Laptop - (Update history)
Surface Studio - (Update history)
Surface Pro 4 - (Update history)
Surface Pro 3 - (Update History)
Surface 3 - (Update History)
Surface Pro Model 1796 and Surface Pro with Advanced LTE Model 1807- (Update History)

These updates are available for devices that are running Windows 10 Creators Update (build 15063) and later versions.

References

More information

Surface hub has implemented defense-in-depth strategies. For more information, see the following topic on the Windows IT Pro Center website:

Differences between Surface Hub and Windows 10 Enterprise

Because of this, we believe that exploits that use these vulnerabilities are significantly reduced on Surface Hub.

The Surface team is focused on making sure that our users have a secure and reliable experience. We will continue to monitor and update devices as required to address these vulnerabilities and keep the devices reliable and secure.

Last Updated: 1 Aug 2019