The system must disable shared salt values.

From VMware vSphere Virtual Machine Version 6 Security Technical Implementation Guide

Part of SRG-OS-000480-VMM-002000

Associated with: CCI-000366

SV-78607r1_rule The system must disable shared salt values.

Vulnerability discussion

When salting is enabled (Mem.ShareForceSalting=1 or 2) in order to share a page between two virtual machines both salt and the content of the page must be same. A salt value is a configurable VMX option for each virtual machine. You can manually specify the salt values in the virtual machine's VMX file with the new VMX option sched.mem.pshare.salt. If this option is not present in the virtual machine's VMX file, then the value of vc.uuid VMX option is taken as the default value. Since the vc.uuid is unique to each virtual machine, by default TPS happens only among the pages belonging to a particular virtual machine (Intra-VM).

Check content

From the vSphere Client select the Virtual Machine right click and go to Edit Settings >> VM Options Tab >> Advanced >> Configuration Parameters. Verify the sched.mem.pshare.salt setting does not exist. Note: The VM must be powered off to view the advanced settings through the vSphere Client so it is recommended to view these settings with PowerCLI as it can be done while the VM is powered on. or From a PowerCLI command prompt while connected to the ESXi host or vCenter server run the following command: Get-VM "VM Name" | Get-AdvancedSetting -Name sched.mem.pshare.salt If the virtual machine advanced setting sched.mem.pshare.salt exists, this is a finding.

Fix text

From a PowerCLI command prompt while connected to the ESXi host or vCenter server run the following command: Get-VM "VM Name" | Get-AdvancedSetting -Name sched.mem.pshare.salt | Remove-AdvancedSetting

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