Check: AOSX-14-000052
Apple OS X 10.14 (Mojave) STIG:
AOSX-14-000052
(in versions v2 r6 through v1 r1)
Title
The macOS system must be configured with the SSH daemon ClientAliveCountMax option set to 0. (Cat II impact)
Discussion
SSH should be configured with an Active Client Alive Maximum Count of 0. 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 "ClientAliveCountMax" option must be set correctly. To verify the SSH idle timeout will occur when the "ClientAliveCountMax" is set, run the following command: /usr/bin/sudo /usr/bin/grep ^ClientAliveCountMax /etc/ssh/sshd_config If the setting is not "ClientAliveCountMax 0", this is a finding.
Fix Text
To ensure that the SSH idle timeout occurs precisely when the "ClientAliveCountMax" is set, run the following command: /usr/bin/sudo /usr/bin/sed -i.bak 's/.*ClientAliveCountMax.*/ClientAliveCountMax 0/' /etc/ssh/sshd_config
Additional Identifiers
Rule ID: SV-209547r610285_rule
Vulnerability ID: V-209547
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 |