Check: Exch-1-502
Exchange 2010 Client Access Server STIG:
Exch-1-502
(in version v1 r9)
Title
Exchange ActiveSync (EAS) must only use certificate-based authentication to access email. (Cat II impact)
Discussion
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 synchronization 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.
Check Content
Open the Exchange Management Shell and enter the following commands: Get-ActiveSyncVirtualDirectory -Identity "<Identity Name>\Microsoft-Server-ActiveSync (Default Web Site)" | fl Basic AuthEnabled,WindowsAuthEnabled,ClientCertAuth,WebSiteSSLEnabled,InternalAuthenticationMethods,ExternalAuthenticationMethods These should be the results returned: BasicAuthEnabled : False WindowsAuthEnabled : False ClientCertAuth : Required WebSiteSSLEnabled : True InternalAuthenticationMethods : {Certificate} ExternalAuthenticationMethods : {Certificate} If the values above are not returned, this is a finding.
Fix Text
Open the Exchange Management Shell and enter the following command: Set-ActiveSyncVirtualDirectory -Identity "ClientAccessServerName\Microsoft-Server-ActiveSync (Default Web Site)" -ClientCertAuth "Required" -WindowsAuthEnabled:$False -InternalAuthenticationMethods "Certificate" –ExternalAuthenticationMethods “Certificate” –ExternalUrl “https://mail-site.easf.csd.disa.mil/Microsoft-Server-ActiveSync”
Additional Identifiers
Rule ID: SV-50983r2_rule
Vulnerability ID: V-39167
Group Title: Exch-1-502
Expert Comments
CCIs
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Controls
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