IIS must map client certificates to Active Directory for Exchange ActiveSync (EAS).

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-39172	Exch-1-505	SV-50988r1_rule	ECSC-1	Medium

Description
Identification and Authentication provide the foundation for access control. For EAS to be used effectively on DoD networks, client certificate authentication must be used for communications between the MEM and email server. Additionally, the internal and external URLs must be set to the same address, since all EAS traffic must be tunneled to the device from the MEM. The risk associated with email syncronization with CMD should be mitigated by the introduction of MEM products and is specified in the DoD CIO memo dated 6 Apr 2011. The memo states specifically, "Email redirection from the email server (e.g., Exchange Server) to the device shall be controlled via centrally managed server." When EAS is used on DoD networks, the devices must be managed by an MEM.

Description

Identification and Authentication provide the foundation for access control. For EAS to be used effectively on DoD networks, client certificate authentication must be used for communications between the MEM and email server. Additionally, the internal and external URLs must be set to the same address, since all EAS traffic must be tunneled to the device from the MEM. The risk associated with email syncronization with CMD should be mitigated by the introduction of MEM products and is specified in the DoD CIO memo dated 6 Apr 2011. The memo states specifically, "Email redirection from the email server (e.g., Exchange Server) to the device shall be controlled via centrally managed server." When EAS is used on DoD networks, the devices must be managed by an MEM.

STIG	Date
Exchange 2010 Client Access Server STIG	2013-07-11

Details

Check Text ( C-46508r4_chk )
Open a command window and enter the following commands: CD C:\Windows\SysWOW64\inetsrv Appcmd.exe list config "Default Web Site/Microsoft-Server-ActiveSync" -section:clientCertificateMappingAuthentication If clientCertificateMappingAuthentication enabled="true" is not returned, this is a finding.

Fix Text (F-44149r2_fix)
Open a command window and enter the following commands: cd C:\Windows\SysWOW64\InetSrv appcmd unlock config /section:clientCertificateMappingAuthentication appcmd set config "Default Web Site/Microsoft-Server-ActiveSync" -section:clientCertificateMappingAuthentication /enabled:true