STIGQter: STIG Summary: Microsoft Exchange 2019 Edge Server Security Technical Implementation Guide Version: 2 Release: 2 Benchmark Date: 30 Jan 2025:

The Exchange sender filter must block unaccepted domains.

DISA Rule

SV-259612r961161_rule

Vulnerability Number

V-259612

Group Title

SRG-APP-000261

Rule Version

EX19-ED-000126

Severity

CAT II

CCI(s)

• CCI-001308 - Automatically update spam protection mechanisms on an organization-defined frequency.

Weight

10

Fix Recommendation

Update the EDSP to reflect the unaccepted domains that are to be blocked.

Open the Exchange Management Shell and enter the following command:

For BlockedDomains:

Set-SenderFilterConfig -BlockedDomains <BlockedDomain>

To add additional domains to the list (array):

Set-SenderFilterConfig -BlockedDomains @{add="<blockeddomain2>","<blockeddomain3>","<blockeddomain4>"}

Each domain added must be quotes and separated by a comma.

Repeat the procedure for each domain that is to be blocked.

or

For BlockedDomainsAndSubdomains:

Set-SenderFilterConfig -BlockedDomainsAndSubdomains <BlockedDomainAndSubdomain>

Same procedure applies for adding multiple domains applies to this filter.

Repeat the procedure for each domain and all of its subdomains that are to be blocked.

Check Contents

Note: If third-party anti-spam product is being used, the anti-spam product must be configured to meet the requirement.

Review the Email Domain Security Plan (EDSP).

Determine the unaccepted domains that are to be blocked.

Open the Exchange Management Shell and enter the following command:

Get-SenderFilterConfig | Select-Object -Property Name, BlockedDomains, BlockedDomainsAndSubdomains

If the value for "BlockedDomains" or "BlockedDomainsAndSubdomains" does not reflect the list of accepted domains, this is a finding.

Vulnerability Number

V-259612

Documentable

False

Rule Version

EX19-ED-000126

Severity Override Guidance

Note: If third-party anti-spam product is being used, the anti-spam product must be configured to meet the requirement.

Review the Email Domain Security Plan (EDSP).

Determine the unaccepted domains that are to be blocked.

Open the Exchange Management Shell and enter the following command:

Get-SenderFilterConfig | Select-Object -Property Name, BlockedDomains, BlockedDomainsAndSubdomains

If the value for "BlockedDomains" or "BlockedDomainsAndSubdomains" does not reflect the list of accepted domains, this is a finding.

Check Content Reference

M

Target Key

5579