Check: ESXI-65-000059
VMware vSphere 6.5 ESXi STIG:
ESXI-65-000059
(in versions v2 r4 through v1 r1)
Title
The virtual switch Forged Transmits policy must be set to reject on the ESXi host. (Cat II impact)
Discussion
If the virtual machine operating system changes the MAC address, the operating system can send frames with an impersonated source MAC address at any time. This allows an operating system to stage malicious attacks on the devices in a network by impersonating a network adaptor authorized by the receiving network. This means the virtual switch does not compare the source and effective MAC addresses. To protect against MAC address impersonation, all virtual switches should have forged transmissions set to Reject. Reject Forged Transmit can be set at the vSwitch and/or the Portgroup level. You can override switch level settings at the Portgroup level.
Check Content
From the vSphere Web Client go to Configure >> Networking >> Virtual Switches. View the properties on each virtual switch and port group and verify "Forged Transmits" is set to reject. or From a PowerCLI command prompt while connected to the ESXi host run the following commands: Get-VirtualSwitch | Get-SecurityPolicy Get-VirtualPortGroup | Get-SecurityPolicy If the "Forged Transmits" policy is set to accept, this is a finding.
Fix Text
From the vSphere Web Client go to Configure >> Networking >> Virtual Switches. For each virtual switch and port group click Edit settings and change "Forged Transmits" to reject. or From a PowerCLI command prompt while connected to the ESXi host run the following commands: Get-VirtualSwitch | Get-SecurityPolicy | Set-SecurityPolicy -ForgedTransmits $false Get-VirtualPortGroup | Get-SecurityPolicy | Set-SecurityPolicy -ForgedTransmitsInherited $true
Additional Identifiers
Rule ID: SV-207658r388482_rule
Vulnerability ID: V-207658
Group Title: SRG-OS-000480-VMM-002000
Expert Comments
CCIs
Number | Definition |
---|---|
CCI-000366 |
The organization implements the security configuration settings. |
Controls
Number | Title |
---|---|
CM-6 |
Configuration Settings |