Windows Speculative Execution Configuration Check

Overview

This page addresses the configuration checks required to mitigate speculative execution vulnerabilities in Windows environments, specifically related to CVEs affecting both hardware and Windows operating systems. These vulnerabilities, including Spectre and Meltdown, can lead to significant information disclosure if not properly mitigated.

• Severity: High

Impact

Exploiting these vulnerabilities can allow an attacker to read sensitive information from the system memory that should have been inaccessible. This includes passwords, encryption keys, and other sensitive data, potentially leading to a full system compromise.

Affected CVEs

The following CVEs are related to speculative execution vulnerabilities that require specific configurations to mitigate:

• CVE-2017-5715
• CVE-2017-5753
• CVE-2017-5754
• CVE-2018-3639
• CVE-2018-3620

Cause

N/A

Solution

To ensure that all virtual machines on a host can utilize firmware capabilities to mitigate these vulnerabilities, set the registry value as follows:

• Registry configuration command:

  reg add "HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Virtualization" /v MinVmVersionForCpuBasedMitigations /t REG_SZ /d "1.0" /f

Patching and Updates:

• SQL Server (CVE-2017-5753): Apply the SQL Server patch available through Windows Server Update Services (WSUS) or the Microsoft Update Catalog but note that this update is not downloaded and installed automatically.
• General Windows Mitigation (CVE-2017-5754): For Windows Server 2019 and client operating systems, mitigations are enabled by default.
• Security Updates for Windows 8.1 and Windows Server 2012 R2 (CVE-2018-3639): Includes quality improvements; no new features introduced.
• L1 Terminal Fault (L1TF) - CVE-2018-3620: Apply patches to protect against L1TF vulnerabilities affecting Intel® processors, detailed in Microsoft's guidance.

Examples

Checking Installed Updates:

systeminfo | findstr /B / C:"KB"

Verifying Registry Settings:

reg query "HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Virtualization" /v MinVmVersionForCpuBasedMitigations

References

• Microsoft Guidance for Spectre and Meltdown
• Details on Speculative Execution Side-channel Vulnerabilities

Additional Resources

N/A