The machine inactivity limit must be set to 15 minutes, locking the system with the screensaver.

STIG ID: WN11-SO-000070  |  SRG: SRG-OS-000279-GPOS-00109 |  Severity: medium |  CCI: CCI-001133,CCI-002361 |  Vulnerability Id: V-253444 | 

Vulnerability Discussion

Unattended systems are susceptible to unauthorized use and must be locked when unattended. The screen saver must 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-000279-GPOS-00109, SRG-OS-000163-GPOS-00072

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.