7.7 Ensure Virtual Disributed Switch Netflow traffic is sent to an authorized collector

Warning! Audit Deprecated

This audit has been deprecated and will be removed in a future update.

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Information

The vSphere VDS can export Netflow information about traffic crossing the VDS. These exports are not encrypted and can contain information about the virtual network making it easier for a Man in the Middle attack to be executed successfully.

Rationale:

If Netflow export is required, verify that all VDS Netflow target systems are approved collectors by confirming the IP's are set correctly.

NOTE: Nessus has not performed this check. Please review the benchmark to ensure target compliance.

Solution

Using the vSphere Web Client

For each distributed switch

Go to 'Configure' -> 'Settings' -> 'NetFlow'.

Click 'Edit'

Set the 'Collector IP address' and 'Collector port' to the organization approved systems.

Additionally, the following PowerCLI command may be used

'# Disable Netfow for a VDPortgroup
$DPortgroup = <name of portgroup>
Get-VDPortgroup $DPortGroup | Disable-PGNetflow

#Function for Disable-PGNetflow
#From: http://www.virtu-al.net/2013/07/23/disabling-netflow-with-powercli/

Function Disable-PGNetflow {
[CmdletBinding()]
Param (
[Parameter(ValueFromPipeline=$true)]
$DVPG
)
Process {
Foreach ($PG in $DVPG) {
$spec = New-Object VMware.Vim.DVPortgroupConfigSpec
$spec.configversion = $PG.Extensiondata.Config.ConfigVersion
$spec.defaultPortConfig = New-Object VMware.Vim.VMwareDVSPortSetting
$spec.defaultPortConfig.ipfixEnabled = New-Object VMware.Vim.BoolPolicy
$spec.defaultPortConfig.ipfixEnabled.inherited = $false
$spec.defaultPortConfig.ipfixEnabled.value = $false

$PGView = Get-View -Id $PG.Id
$PGView.ReconfigureDVPortgroup_Task($spec)
}
}
}

See Also

https://workbench.cisecurity.org/files/3511