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Table Of Contents
Securing Virtual Machines 5
The guest operating system that runs in the virtual machine is subject to the same security risks as a
physical system. Secure virtual machines just like physical machines, and follow best practices discussed
in this document and in the Hardening Guide.
This chapter includes the following topics:
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Enable or Disable UEFI Secure Boot for a Virtual Machine
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Limit Informational Messages From Virtual Machines to VMX Files
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Prevent Virtual Disk Shrinking
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Virtual Machine Security Best Practices
Enable or Disable UEFI Secure Boot for a Virtual Machine
UEFI Secure Boot is a security standard that helps ensure that your PC boots using only software that is
trusted by the PC manufacturer. For certain virtual machine hardware versions and operating systems,
you can enable secure boot just as you can for a physical machine.
In an operating system that supports UEFI secure boot, each piece of boot software is signed, including
the bootloader, the operating system kernel, and operating system drivers. The virtual machine's default
configuration includes several code signing certificates.
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A Microsoft certificate that is used only for booting Windows.
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A Microsoft certificate that is used for third-party code that is signed by Microsoft, such as Linux
bootloaders.
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A VMware certificate that is used only for booting ESXi inside a virtual machine.
The virtual machine's default configuration includes one certificate for authenticating requests to modify
the secure boot configuration, including the secure boot revocation list, from inside the virtual machine,
which is a Microsoft KEK (Key Exchange Key) certificate.
In almost all cases, it is not necessary to replace the existing certificates. If you do want to replace the
certificates, see the VMware Knowledge Base system.
VMware Tools version 10.1 or later is required for virtual machines that use UEFI secure boot. You can
upgrade those virtual machines to a later version of VMware Tools when it becomes available.
VMware, Inc.
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