STIGQter: STIG Summary: Microsoft Exchange 2016 Mailbox Server Security Technical Implementation Guide Version: 2 Release: 3 Benchmark Date: 23 Apr 2021:

Exchange Message size restrictions must be controlled on Send connectors.

DISA Rule

SV-228385r612748_rule

Vulnerability Number

V-228385

Group Title

SRG-APP-000247

Rule Version

EX16-MB-000410

Severity

CAT III

CCI(s)

• CCI-001095 - The information system manages excess capacity, bandwidth, or other redundancy to limit the effects of information flooding types of denial of service attacks.

Weight

10

Fix Recommendation

Update the EDSP to specify the "MaxMessageSize" value or verify that this information is documented by the organization.

Open the Exchange Management Shell and enter the following command:

Set-SendConnector -Identity <'IdentityName'> -MaxMessageSize <MaxSendSize>

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

or

Enter the value as identified by the EDSP that has obtained a signoff with risk acceptance.

Repeat the procedures for each Send connector.

Check Contents

Review the Email Domain Security Plan (EDSP) or document that contains this information.

Determine the maximum message send size.

Open the Exchange Management Shell and enter the following command:

Get-SendConnector | Select Name, Identity, MaxMessageSize

For each Send connector, if the value of "MaxMessageSize" is not the same as the global value, this is a finding.

or

If "MaxMessageSize" is set to a numeric value different from the maximum message send size value documented in the EDSP, this is a finding.

Vulnerability Number

V-228385

Documentable

False

Rule Version

EX16-MB-000410

Severity Override Guidance

Review the Email Domain Security Plan (EDSP) or document that contains this information.

Determine the maximum message send size.

Open the Exchange Management Shell and enter the following command:

Get-SendConnector | Select Name, Identity, MaxMessageSize

For each Send connector, if the value of "MaxMessageSize" is not the same as the global value, this is a finding.

or

If "MaxMessageSize" is set to a numeric value different from the maximum message send size value documented in the EDSP, this is a finding.

Check Content Reference

M

Target Key

4223

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