Title

Exchange must have accepted domains configured. (Cat II impact)

Discussion

Exchange may be configured to accept email for multiple domain names. This setting identifies the domains for which the server will accept mail. This check verifies the email server is not accepting email for unauthorized domains.

Check Content

Review the Email Domain Security Plan (EDSP). Determine the Accepted Domain values. Open the Exchange Management Shell and enter the following command: Get-AcceptedDomain | Select Name, DomainName, Identity, Default If the value of "Default" is not set to "True", this is a finding. or If the "Default" value for "AcceptedDomains" is set to another value other than "True" and has signoff and risk acceptance in the EDSP, this is not a finding.

Fix Text

Update the EDSP. Open the Exchange Management Shell and enter the following command: Set-AcceptedDomain -Identity <'IdentityName'> -MakeDefault $true Note: The <IdentityName> value must be in single quotes.

Additional Identifiers

Rule ID: SV-221204r879533_rule

Vulnerability ID: V-221204

Group Title: SRG-APP-000038

Expert Comments

CCIs tied to check.

Controls tied to check. These are derived from the CCIs shown above.