Title

Maximum Inbound Connection Timeout Limit is not 10 or less. (Cat III impact)

Discussion

E-Mail system availability depends in part on best practices strategies for setting tuning configurations. 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. The default of 10 minutes is a reasonable window in which to resume activities without maintaining idle connections for excessive intervals. If the timeout period is too long, idle connections may be maintained for unnecessarily long time periods, preventing new connections from being established. Sluggish connectivity increases the risk of lost data. A value of 10 or less is optimal.

Check Content

Access the mail server connection timeout configuration. Exchange System Manager >> Administrative Groups >> [administrative group] >> Servers >> [Server] >> Protocols >> SMTP >> [specific SMTP server] >> properties >> General tab Ensure the “Connection Timeout” value is = 10 or less. Criteria: If the ‘Inbound Connections Timeout Limit’ value is at 10 or less, this is not a finding.

Fix Text

Set the Inbound Connection Timeout limit. Procedure: Exchange System Manager >> administrative groups >> [administrative group] >> Servers >> [Server] >> Protocols >> SMTP >> [specific SMTP server] >> properties >> General tab Enter "Connection timeout" value = 10. If a value less than 10 is desired for the site, and is documented in the System Security Plan, then enter a value less than 10.

Additional Identifiers

Rule ID: SV-20326r1_rule

Vulnerability ID: V-18693

Group Title:

Expert Comments

CCIs tied to check.

Controls tied to check. These are derived from the CCIs shown above.