Windows Server 2019 User Account Control (UAC) must virtualize file and registry write failures to per-user locations.

STIG ID: WN19-SO-000450  |  SRG: SRG-OS-000134-GPOS-00068 |  Severity: medium |  CCI: CCI-001084 |  Vulnerability Id: V-205720 | 

Vulnerability Discussion

UAC is a security mechanism for limiting the elevation of privileges, including administrative accounts, unless authorized. This setting configures non-UAC-compliant applications to run in virtualized file and registry entries in per-user locations, allowing them to run.

Check

UAC requirements are NA for Server Core installations (this is the default installation option for Windows Server 2019 versus Server with Desktop Experience).

If the following registry value does not exist or is not configured as specified, this is a finding:

Registry Hive: HKEY_LOCAL_MACHINE
Registry Path: \SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System\

Value Name: EnableVirtualization

Value Type: REG_DWORD
Value: 0x00000001 (1)

Fix

Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> Security Options >> "User Account Control: Virtualize file and registry write failures to per-user locations" to "Enabled".