ESXI-67-000060 - The virtual switch MAC Address Change policy must be set to reject on the ESXi host.

Information

If the virtual machine operating system changes the MAC address, it can send frames with an impersonated source MAC address at any time. This allows it to stage malicious attacks on the devices in a network by impersonating a network adaptor authorized by the receiving network.

This will prevent VMs from changing their effective MAC address. It will affect applications that require this functionality, how a layer 2 bridge will operate, and applications that require a specific MAC address for licensing. Reject MAC Changes can be set at the vSwitch and/or the Portgroup level. Switch-level settings can be overridden at the Portgroup level.

Solution

From the vSphere Client, go to Configure >> Networking >> Virtual Switches.

For each virtual switch and port group, click Edit settings (dots) and change 'MAC Address Changes' to reject.

or

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

Get-VirtualSwitch | Get-SecurityPolicy | Set-SecurityPolicy -MacChanges $false
Get-VirtualPortGroup | Get-SecurityPolicy | Set-SecurityPolicy -MacChangesInherited $true

See Also

https://dl.dod.cyber.mil/wp-content/uploads/stigs/zip/U_VMW_vSphere_6-7_Y23M07_STIG.zip

Item Details

Category: CONFIGURATION MANAGEMENT

References: 800-53|CM-6b., CAT|I, CCI|CCI-000366, Rule-ID|SV-239314r674871_rule, STIG-ID|ESXI-67-000060, Vuln-ID|V-239314

Plugin: VMware

Control ID: a2e3d788cff1f57c8a5793f19cd4b013e02811fb8c18b5ba2cc522ed51bfea69