CVE-2024-2201: Intel: CVE-2024-2201 Branch History Injection

Why is this Intel CVE included in the Security Update Guide?

The vulnerability assigned to this CVE is in certain processor models offered by Intel. The mitigation for this vulnerability is disabled by default and manual action is required for customers to be protected. This CVE is being documented in the Security Update Guide to inform customers of the available mitigation and its potential performance impact.

Please see the following for more information:

• CVE-2024-2201
• https://www.intel.com/content/www/us/en/developer/articles/technical/software-security-guidance/advisory-guidance/branch-history-injection.html

What steps are required to protect my system against the vulnerability?

We are providing the following registry information to enable the mitigations for this CVE.

Important: This section, method, or task contains steps that tell you how to modify the registry. However, serious problems might occur if you modify the registry incorrectly. Therefore, make sure that you follow these steps carefully. For added protection, back up the registry before you modify it. Then, you can restore the registry if a problem occurs. For more information about how to back up and restore the registry see How to back up and restore the registry in Windows.

To enable the mitigation for CVE-2024-2201 on Windows devices and clients using Intel Processors:

• reg add “HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management” /v FeatureSettingsOverride /t REG_DWORD /d 0x00800000 /f

• reg add “HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management” /v FeatureSettingsOverrideMask /t REG_DWORD /d 0x00000003 /f

Customers who wish to implement the mitigation within their systems can also refer to the following for more information.

• Windows Server and Azure Stack HCI customers: See Microsoft Knowledge Base Article 4072698
• Windows client guidance for IT Pros: See Microsoft Knowledge Base Article 4073119
• Windows Device customers: See Microsoft Knowledge Base Article 4073757

To enable the mitigation for CVE-2024-2201 on Linux devices and clients using Intel Processors:

• Specify spectre_bhi=on on the kernel command line. For more information about kernel command-line parameters see https://www.kernel.org/doc/html/latest/admin-guide/kernel-parameters.html

Can I expect any performance impact after I configure the registry keys?

In some cases, installing these updates will have a performance impact. In testing Microsoft has seen some performance impact with this mitigation. Microsoft values the security of its software and services but made the decision to allow users and administrators to evaluate the performance impact and risk exposure before deciding to enable the mitigation.