Details

Users can share their calendars with others by publishing them to the Microsoft Office Online Calendar Sharing Services and to a server that supports the World Wide Web Distributed Authoring and Versioning (WebDAV) protocol. Office Online allows users to choose whether to restrict access to their calendars to people they invite, or allow unrestricted access to anyone who knows the URL to reach the calendar. DAV access restrictions can only be achieved through server and folder permissions, and might require the assistance of a server administrator to set up and maintain.

If a calendar is visible to anyone on Office Online or third-party DAV servers, sensitive calendar information might be revealed.

Solution

Set the policy value for User Configuration -> Administrative Templates -> Microsoft Outlook 2013 -> Outlook Options -> Preferences -> Calendar Options -> Office.com Sharing Service ‘Access to published calendars’ to ‘Enabled’.

Supportive Information

The following resource is also helpful.

• https://iasecontent.disa.mil/stigs/zip/U_MS_Outlook_2013_V1R13_STIG.zip

This security hardening control applies to the following category of controls within NIST 800-53: Configuration Management.This control applies to the following type of system Windows.

References

• 800-53|CM-6b.
• CAT|II
• CCI|CCI-000366
• Rule-ID|SV-53872r1_rule
• STIG-ID|DTOO219
• Vuln-ID|V-17546

Source

• Tenable.com/audits