Exchange must limit the Receive connector timeout.

From Microsoft Exchange 2016 Edge Transport Server Security Technical Implementation Guide

Associated with: CCI-000054

SV-95195r1_rule Exchange must limit the Receive connector timeout.

Vulnerability discussion

Email system availability depends in part on best practices strategies for setting tuning. This configuration controls the number of idle minutes before the connection is dropped. It works in conjunction with the Maximum Inbound Connections Count setting. Connections, once established, may incur delays in message transfer. If the timeout period is too long, there is risk that connections may be maintained for unnecessarily long time periods, preventing new connections from being established.

Check content

Review the Email Domain Security Plan (EDSP), or Organizations applicable documentation. Determine the connection Timeout value. Open the Exchange Management Shell and enter the following command: Get-ReceiveConnector | Select Name, Identity, ConnectionTimeout For each Receive connector, if the value of "ConnectionTimeout" is not set to "00:05:00", this is a finding. or If "ConnectionTimeout" is set to another value other than "00:05:00" and has signoff and risk acceptance in the EDSP, this is not a finding.

Fix text

Update the EDSP, or the applicable documentation. Open the Exchange Management Shell and enter the following command: Set-ReceiveConnector -Identity <'IdentityName'> -ConnectionTimeout 00:05:00 Note: The value must be in single quotes. or The value as identified by the EDSP that has obtained a signoff with risk acceptance. Repeat the procedures for each Receive connector.

Pro Tips

Lavender hyperlinks in small type off to the right (of CSS class id, if you view the page source) point to globally unique URIs for each document and item. Copy the link location and paste anywhere you need to talk unambiguously about these things.

You can obtain data about documents and items in other formats. Simply provide an HTTP header Accept: text/turtle or Accept: application/rdf+xml.