The SSH daemon ClientAliveInterval option must be set correctly.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-51347	OSX8-00-00715	SV-65557r1_rule		Medium

Description
This requirement applies to both internal and external networks. Terminating network connections associated with communications sessions means de-allocating associated TCP/IP address/port pairs at the operating system level. The time period of inactivity may, as the organization deems necessary, be a set of time periods by type of network access or for specific accesses.

STIG	Date
Apple OS X 10.8 (Mountain Lion) Workstation STIG	2015-02-10

Details

Check Text ( C-53693r1_chk )
To check which the idle timeout setting for SSH sessions, run the following: grep ClientAliveInterval /etc/sshd_config If these setting is not "600", or commented out, this is a finding.

Fix Text (F-56145r1_fix)
In order to make sure that the correct ClientAliveInterval is set correctly, run the following command: sudo sed -i.bak 's/.*ClientAliveInterval.*/ClientAliveInterval 600/' /etc/sshd_config