STIGQter: STIG Summary: Microsoft Exchange 2019 Mailbox Server Security Technical Implementation Guide Version: 2 Release: 3 Benchmark Date: 02 Jul 2025:

The Exchange Outbound Connection Timeout must be 10 minutes or less.

DISA Rule

SV-259685r961155_rule

Vulnerability Number

V-259685

Group Title

SRG-APP-000247

Rule Version

EX19-MB-000132

Severity

CAT III

CCI(s)

• CCI-001095 - Manage 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 "ConnectionInactivityTimeOut" value.

Open the Exchange Management Shell and enter the following command:

Set-SendConnector -Identity <'IdentityName'> -ConnectionInactivityTimeOut 00:10:00

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

or

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

Check Contents

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

Determine the Connection Timeout value.

Open the Exchange Management Shell and enter the following command:

Get-SendConnector | Select-Object -Property Name, Identity, ConnectionInactivityTimeOut

For each Send connector, if the value of "ConnectionInactivityTimeOut" is not set to "00:10:00", this is a finding.

or

If "ConnectionInactivityTimeOut" is set to a value other than "00:10:00" and has signoff and risk acceptance in the EDSP, this is not a finding.

Vulnerability Number

V-259685

Documentable

False

Rule Version

EX19-MB-000132

Severity Override Guidance

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

Determine the Connection Timeout value.

Open the Exchange Management Shell and enter the following command:

Get-SendConnector | Select-Object -Property Name, Identity, ConnectionInactivityTimeOut

For each Send connector, if the value of "ConnectionInactivityTimeOut" is not set to "00:10:00", this is a finding.

or

If "ConnectionInactivityTimeOut" is set to a value other than "00:10:00" and has signoff and risk acceptance in the EDSP, this is not a finding.

Check Content Reference

M

Target Key

5580