STIGQter: STIG Summary: Microsoft Exchange 2013 Mailbox Server Security Technical Implementation Guide Version: 2 Release: 1 Benchmark Date: 22 Jan 2021:

The Exchange Outbound Connection Limit per Domain Count must be controlled.

DISA Rule

SV-207311r615936_rule

Vulnerability Number

V-207311

Group Title

SRG-APP-000247

Rule Version

EX13-MB-000225

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

Fix Recommendation

Update the EDSP.

Open the Exchange Management Shell and enter the following command:

Set-TransportService -Identity <'IdentityName'> -MaxPerDomainOutboundConnections 20

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

or

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

Check Contents

Review the Email Domain Security Plan (EDSP).

Determine the value for Maximum Domain Connections

Open the Exchange Management Shell and enter the following command:

Get-TransportService | Select Name, Identity, MaxPerDomainOutboundConnections

If the value of MaxPerDomainOutboundConnections is not set to 20, this is a finding.

or

If the value of MaxPerDomainOutboundConnections is set to a value other than 20 and has signoff and risk acceptance in the EDSP, this is not a finding.

The Exchange Outbound Connection Limit per Domain Count must be controlled.

DISA Rule

Vulnerability Number

Group Title

Rule Version

Severity

CCI(s)

Weight

Fix Recommendation

Check Contents

Vulnerability Number

Documentable

Rule Version

Severity Override Guidance

Check Content Reference

Target Key

Comments