The vCenter Server for Windows must set the distributed port group Promiscuous Mode policy to reject.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-94741	VCWN-65-000015	SV-104571r1_rule		Medium

Description
When promiscuous mode is enabled for a virtual switch all virtual machines connected to the Portgroup have the potential of reading all packets across that network, meaning only the virtual machines connected to that Portgroup. Promiscuous mode is disabled by default on the ESXi Server, and this is the recommended setting.

STIG	Date
VMware vSphere 6.5 vCenter Server for Windows Security Technical Implementation Guide	2020-03-27

Details

Check Text ( C-93931r1_chk )
From the vSphere Web Client go to Networking >> Select a distributed switch >> Select a port group >> Configure >> Settings >> Policies Verify "Promiscuous Mode" is set to reject. or From a PowerCLI command prompt while connected to the vCenter server run the following commands: Get-VDSwitch \| Get-VDSecurityPolicy Get-VDPortgroup \| ?{$_.IsUplink -eq $false} \| Get-VDSecurityPolicy If the "Promiscuous Mode" policy is set to accept, this is a finding.

Check Text ( C-93931r1_chk )

From the vSphere Web Client go to Networking >> Select a distributed switch >> Select a port group >> Configure >> Settings >> Policies

Verify "Promiscuous Mode" is set to reject.

or

From a PowerCLI command prompt while connected to the vCenter server run the following commands:
Get-VDSwitch | Get-VDSecurityPolicy
Get-VDPortgroup | ?{$_.IsUplink -eq $false} | Get-VDSecurityPolicy

If the "Promiscuous Mode" policy is set to accept, this is a finding.

Fix Text (F-100859r1_fix)
From the vSphere Web Client go to Networking >> Select a distributed switch >> Select a port group >> Configure >> Settings >> Policies >> Edit >> Security. Set "Promiscuous Mode" to reject. Click "OK". or From a PowerCLI command prompt while connected to the vCenter server run the following commands: Get-VDSwitch \| Get-VDSecurityPolicy \| Set-VDSecurityPolicy -AllowPromiscuous $false Get-VDPortgroup \| ?{$_.IsUplink -eq $false} \| Get-VDSecurityPolicy \| Set-VDSecurityPolicy -AllowPromiscuous $false

Fix Text (F-100859r1_fix)

From the vSphere Web Client go to Networking >> Select a distributed switch >> Select a port group >> Configure >> Settings >> Policies >> Edit >> Security. Set "Promiscuous Mode" to reject. Click "OK".

or

From a PowerCLI command prompt while connected to the vCenter server run the following commands:
Get-VDSwitch | Get-VDSecurityPolicy | Set-VDSecurityPolicy -AllowPromiscuous $false
Get-VDPortgroup | ?{$_.IsUplink -eq $false} | Get-VDSecurityPolicy | Set-VDSecurityPolicy -AllowPromiscuous $false