Windows Server 2019 machine inactivity limit must be set to 15 minutes or less, locking the system with the screen saver.

STIG ID: WN19-SO-000120  |  SRG: SRG-OS-000028-GPOS-00009 |  Severity: medium |  CCI: CCI-000056,CCI-000057,CCI-000060 |  Vulnerability Id: V-205633 | 

Vulnerability Discussion

Unattended systems are susceptible to unauthorized use and should be locked when unattended. The screen saver should be set at a maximum of 15 minutes and be password protected. This protects critical and sensitive data from exposure to unauthorized personnel with physical access to the computer.

Satisfies: SRG-OS-000028-GPOS-00009, SRG-OS-000029-GPOS-00010, SRG-OS-000031-GPOS-00012

Check

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: InactivityTimeoutSecs

Value Type: REG_DWORD
Value: 0x00000384 (900) (or less, excluding "0" which is effectively disabled)

Fix

Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> Security Options >> "Interactive logon: Machine inactivity limit" to "900" seconds or less, excluding "0" which is effectively disabled.