The ESXi host must enable volatile key destruction.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-258780	ESXI-80-000225	SV-258780r959010_rule		Medium

Description
By default, pages allocated for virtual machines (VMs), userspace applications, and kernel threads are zeroed out at allocation time. ESXi will always ensure that no nonzero pages are exposed to VMs or userspace applications. While this prevents exposing cryptographic keys from VMs or userworlds to other clients, these keys can stay present in host memory for a long time if the memory is not reused. The NIAP Virtualization Protection Profile and Server Virtualization Extended Package require that memory that may contain cryptographic keys be zeroed upon process exit. To this end, a new configuration option, MemEagerZero, can be configured to enforce zeroing out userworld and guest memory pages when a userworld process or guest exits. For kernel threads, memory spaces holding keys are zeroed out as soon as the secret is no longer needed.

Description

By default, pages allocated for virtual machines (VMs), userspace applications, and kernel threads are zeroed out at allocation time. ESXi will always ensure that no nonzero pages are exposed to VMs or userspace applications. While this prevents exposing cryptographic keys from VMs or userworlds to other clients, these keys can stay present in host memory for a long time if the memory is not reused. The NIAP Virtualization Protection Profile and Server Virtualization Extended Package require that memory that may contain cryptographic keys be zeroed upon process exit. To this end, a new configuration option, MemEagerZero, can be configured to enforce zeroing out userworld and guest memory pages when a userworld process or guest exits. For kernel threads, memory spaces holding keys are zeroed out as soon as the secret is no longer needed.

STIG	Date
VMware vSphere 8.0 ESXi Security Technical Implementation Guide	2024-07-11

Details

Check Text ( C-62520r933399_chk )
From the vSphere Client, go to Hosts and Clusters. Select the ESXi Host >> Configure >> System >> Advanced System Settings. Select the "Mem.MemEagerZero" value and verify it is set to "1". or From a PowerCLI command prompt while connected to the ESXi host, run the following command: Get-VMHost \| Get-AdvancedSetting -Name Mem.MemEagerZero If the "Mem.MemEagerZero" setting is not set to "1", this is a finding.

Check Text ( C-62520r933399_chk )

From the vSphere Client, go to Hosts and Clusters.

Select the ESXi Host >> Configure >> System >> Advanced System Settings.

Select the "Mem.MemEagerZero" value and verify it is set to "1".

or

From a PowerCLI command prompt while connected to the ESXi host, run the following command:

Get-VMHost | Get-AdvancedSetting -Name Mem.MemEagerZero

If the "Mem.MemEagerZero" setting is not set to "1", this is a finding.

Fix Text (F-62429r933400_fix)
From the vSphere Client, go to Hosts and Clusters. Select the ESXi Host >> Configure >> System >> Advanced System Settings. Click "Edit". Select the "Mem.MemEagerZero" value and configure it to "1". or From a PowerCLI command prompt while connected to the ESXi host, run the following command: Get-VMHost \| Get-AdvancedSetting -Name Mem.MemEagerZero \| Set-AdvancedSetting -Value 1