Internet calendar integration in Outlook must be disabled.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-17678	DTOO285	SV-54058r1_rule		Medium

Description
The Internet Calendar feature in Outlook enables users to publish calendars online (using the webcal:// protocol) and subscribe to calendars that others have published. When users subscribe to an Internet calendar, Outlook queries the calendar at regular intervals and downloads any changes as they are posted. By default, Outlook allows users to subscribe to Internet calendars. When an organization has policies that govern the use of external resources such as Internet calendars, this feature will enable users to violate those policies.

Description

The Internet Calendar feature in Outlook enables users to publish calendars online (using the webcal:// protocol) and subscribe to calendars that others have published. When users subscribe to an Internet calendar, Outlook queries the calendar at regular intervals and downloads any changes as they are posted. By default, Outlook allows users to subscribe to Internet calendars. When an organization has policies that govern the use of external resources such as Internet calendars, this feature will enable users to violate those policies.

STIG	Date
Microsoft Outlook 2013 STIG	2018-09-05

Details

Check Text ( C-47998r1_chk )
Verify the policy value for User Configuration -> Administrative Templates -> Microsoft Outlook 2013 -> Account Settings -> Internet Calendars "Do not include Internet Calendar integration in Outlook" is set to "Enabled". Procedure: Use the Windows Registry Editor to navigate to the following key: HKCU\Software\Policies\Microsoft\Office\15.0\outlook\options\webcal Criteria: If the value Disable is REG_DWORD = 1, this is not a finding.

Check Text ( C-47998r1_chk )

Verify the policy value for User Configuration -> Administrative Templates -> Microsoft Outlook 2013 -> Account Settings -> Internet Calendars "Do not include Internet Calendar integration in Outlook" is set to "Enabled".

Procedure: Use the Windows Registry Editor to navigate to the following key:

HKCU\Software\Policies\Microsoft\Office\15.0\outlook\options\webcal

Criteria: If the value Disable is REG_DWORD = 1, this is not a finding.

Fix Text (F-46938r1_fix)
Set the policy value for User Configuration -> Administrative Templates -> Microsoft Outlook 2013 -> Account Settings -> Internet Calendars "Do not include Internet Calendar integration in Outlook" to "Enabled".