Check: AOSX-12-000720
Apple OS X 10.12 STIG:
AOSX-12-000720
(in versions v1 r6 through v1 r1)
Title
The OS X system must be configured with the SSH daemon ClientAliveInterval option set to 900 or less. (Cat II impact)
Discussion
SSH should be configured to log users out after a 15-minute interval of inactivity and to wait only 30 seconds before timing out logon attempts. Terminating an idle session within a short time period reduces the window of opportunity for unauthorized personnel to take control of a management session enabled on the console or console port that has been left unattended. In addition, quickly terminating an idle session or an incomplete logon attempt will also free up resources committed by the managed network element.
Check Content
The SSH daemon "ClientAliveInterval" option must be set correctly. To check the idle timeout setting for SSH sessions, run the following: /usr/bin/sudo /usr/bin/grep ^ClientAliveInterval /etc/ssh/sshd_config If the setting is not "900" or less, this is a finding.
Fix Text
To ensure that "ClientAliveInterval" is set correctly, run the following command: /usr/bin/sudo /usr/bin/sed -i.bak 's/.*ClientAliveInterval.*/ClientAliveInterval 900/' /etc/ssh/sshd_config
Additional Identifiers
Rule ID: SV-90777r1_rule
Vulnerability ID: V-76089
Group Title: SRG-OS-000163-GPOS-00072
Expert Comments
CCIs
Number | Definition |
---|---|
CCI-001133 |
The information system terminates the network connection associated with a communications session at the end of the session or after an organization-defined time period of inactivity. |
Controls
Number | Title |
---|---|
SC-10 |
Network Disconnect |