VMCH-65-000033 - Console connection sharing must be limited on the virtual machine.

Information

By default, remote console sessions can be connected to by more than one user at a time. When multiple sessions are activated, each terminal window gets a notification about the new session. If an administrator in the VM logs in using a VMware remote console during their session, a non-administrator in the VM might connect to the console and observe the administrator's actions. Also, this could result in an administrator losing console access to a virtual machine. For example, if a jump box is being used for an open console session and the admin loses connection to that box, then the console session remains open. Allowing two console sessions permits debugging via a shared session. For highest security, only one remote console session at a time should be allowed.

Solution

From the vSphere Web Client right-click the Virtual Machine and go to Edit Settings >> VM Options >> Advanced >> Configuration Parameters >> Edit Configuration. Find the RemoteDisplay.maxConnections value and set it to 1. If the setting does not exist, add the Name and Value setting at the bottom of screen.

Note: The VM must be powered off to configure the advanced settings through the vSphere Web Client so it is recommended to configure these settings with PowerCLI as it can be done while the VM is powered on. Settings do not take effect via either method until the virtual machine is cold started, not rebooted.

or

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

If the setting does not exist, run:

Get-VM 'VM Name' | New-AdvancedSetting -Name RemoteDisplay.maxConnections -Value 1

If the setting exists, run:

Get-VM 'VM Name' | Get-AdvancedSetting -Name RemoteDisplay.maxConnections | Set-AdvancedSetting -Value 1

See Also

https://dl.dod.cyber.mil/wp-content/uploads/stigs/zip/U_VMW_vSphere_6-5_Y21M07_STIG.zip

Item Details

Category: CONFIGURATION MANAGEMENT

References: 800-53|CM-6, CAT|II, CCI|CCI-000366, Rule-ID|SV-104453r1_rule, STIG-ID|VMCH-65-000033, Vuln-ID|V-94623

Plugin: VMware

Control ID: fdeaa5764bdcc356f9ddd54fad471950389f4b2b5837792e79ee9d7ef28c573a