STIGQter: STIG Summary: Microsoft Exchange 2016 Edge Transport Server Security Technical Implementation Guide Version: 2 Release: 6 Benchmark Date: 30 Jan 2025:

Exchange internal Send connectors must use domain security (mutual authentication Transport Layer Security).

DISA Rule

SV-221218r1043178_rule

Vulnerability Number

V-221218

Group Title

SRG-APP-000219

Rule Version

EX16-ED-000170

Severity

CAT II

CCI(s)

• CCI-001184 - Protect the authenticity of communications sessions.

Weight

10

Fix Recommendation

Open the Exchange Management Shell and enter the following command:

Set-SendConnector <'IdentityName'> -DomainSecureEnabled $true

Note: The <IdentityName> value must be in single quotes.

Repeat the procedures for each send connector.

The following commands can be executed if smarthosts are used:

Set-SendConnector <'IdentityName'> -RequireTLS $true -DNSRoutingEnabled $False -TlsAuthLevel $DomainValidation

Check Contents

Open the Exchange Management Shell and enter the following command:

Get-SendConnector | Select Name, Identity, DomainSecureEnabled, DNSRoutingEnabled, RequireTLS, TlsAuthLevel

For each send connector:

If the send connector does not use a smarthost and the value of "DomainSecureEnabled" is not set to "True", this is a finding.

If the send connector does use a smarthost, "DomainSecureEnabled" will be set to "False".

If the send connector does use a smarthost "DNSRoutingEnabled", "RequireTLS", and "TlsAuthLevel" must be set.

If the send connector using a smart host has a value for “DNSRoutingEnabled” that is not set to “False”, this is a finding.

If the send connector using a smarthost has a value for “RequireTLS” that is not set to “True”, this is a finding.

If the send connector using a smarthost has a value for “TlsAuthLevel” that is not set to “DomainValidation”, this is a finding.

Vulnerability Number

V-221218

Documentable

False

Rule Version

EX16-ED-000170

Severity Override Guidance

Open the Exchange Management Shell and enter the following command:

Get-SendConnector | Select Name, Identity, DomainSecureEnabled, DNSRoutingEnabled, RequireTLS, TlsAuthLevel

For each send connector:

If the send connector does not use a smarthost and the value of "DomainSecureEnabled" is not set to "True", this is a finding.

If the send connector does use a smarthost, "DomainSecureEnabled" will be set to "False".

If the send connector does use a smarthost "DNSRoutingEnabled", "RequireTLS", and "TlsAuthLevel" must be set.

If the send connector using a smart host has a value for “DNSRoutingEnabled” that is not set to “False”, this is a finding.

If the send connector using a smarthost has a value for “RequireTLS” that is not set to “True”, this is a finding.

If the send connector using a smarthost has a value for “TlsAuthLevel” that is not set to “DomainValidation”, this is a finding.

Check Content Reference

M

Target Key

4079