Publishing calendars to Office Online must be prevented.

Severity	Group ID	Group Title	Version	Rule ID	Date	STIG Version
medium	V-228429	SRG-APP-000516	DTOO216	SV-228429r508021_rule	2022-03-11	2

Description
This policy setting controls whether Outlook users can publish their calendars to the Office.com Calendar Sharing Service. If you enable this policy setting, Outlook users cannot publish their calendars to Office.com. If you disable do not configure this policy setting, Outlook users can share their calendars with selected others by publishing them to the Microsoft Outlook Calendar Sharing Service. Users can control who can view their calendar and at what level of detail.

Description

This policy setting controls whether Outlook users can publish their calendars to the Office.com Calendar Sharing Service. If you enable this policy setting, Outlook users cannot publish their calendars to Office.com. If you disable do not configure this policy setting, Outlook users can share their calendars with selected others by publishing them to the Microsoft Outlook Calendar Sharing Service. Users can control who can view their calendar and at what level of detail.

ℹ️ Check
Verify the policy value for User Configuration -> Administrative Templates -> Microsoft Outlook 2016 -> Outlook Options -> Preferences -> Calendar Options -> Office.com Sharing Service "Prevent publishing to Office.com" is set to "Enabled". Procedure: Use the Windows Registry Editor to navigate to the following key: HKCU\Software\Policies\Microsoft\Office\16.0\outlook\options\pubcal Criteria: If the value DisableOfficeOnline is REG_DWORD = 1, this is not a finding.

ℹ️ Check

Verify the policy value for User Configuration -> Administrative Templates -> Microsoft Outlook 2016 -> Outlook Options -> Preferences -> Calendar Options -> Office.com Sharing Service "Prevent publishing to Office.com" is set to "Enabled". Procedure: Use the Windows Registry Editor to navigate to the following key: HKCU\Software\Policies\Microsoft\Office\16.0\outlook\options\pubcal Criteria: If the value DisableOfficeOnline is REG_DWORD = 1, this is not a finding.

✔️ Fix
Set the policy value for User Configuration -> Administrative Templates -> Microsoft Outlook 2016 -> Outlook Options -> Preferences -> Calendar Options -> Office.com Sharing Service "Prevent publishing to Office.com" to "Enabled".