Details

Attackers can use automated messages to determine whether a user account is active, in the office, traveling, and so on. An attacker might use this information to conduct future attacks. Verify Automatic Forwards to remote domains are disabled, except for enterprise mail that must be restricted to forward only to .mil and .gov. domains.

Before enabling this setting, configure a remote domain.

Solution

Non-Enterprise Mail Fix Text:

Open the Exchange Management Shell and enter the following command:

Set-RemoteDomain -Identity <'IdentityName'> -AutoForwardEnabled $false

Note: The value must be in single quotes.

Enterprise Mail Fix Text:

New-RemoteDomain -Name -DomainName

Note: must either be a .mil or .gov domain.

Set-RemoteDomain -Identity <'RemoteDomainIdentity'> -AutoForwardEnabled $true

Note: The value must be in single quotes.

Supportive Information

The following resource is also helpful.

• https://dl.dod.cyber.mil/wp-content/uploads/stigs/zip/U_MS_Exchange_2016_Y21M07_STIG.zip

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

References

• 800-53|AC-4
• CAT|II
• CCI|CCI-001368
• Rule-ID|SV-228356r612748_rule
• STIG-ID|EX16-MB-000030
• STIG-Legacy|SV-95337
• STIG-Legacy|V-80627
• Vuln-ID|V-228356

Source

• Tenable.com/audits