Title

The macOS system must be configured with the SSH daemon LoginGraceTime set to 30 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

If SSH is not being used, this is Not Applicable. The SSH daemon "LoginGraceTime" must be set correctly. To check the amount of time that a user can log on through SSH, run the following command: /usr/bin/grep -r ^LoginGraceTime /etc/ssh/sshd_config* If the value is not set to "30" or less, this is a finding. If conflicting results are returned, this is a finding.

Fix Text

To ensure that "LoginGraceTime" is configured correctly, run the following command: /usr/bin/sudo /usr/bin/sed -i.bak 's/.*LoginGraceTime.*/LoginGraceTime 30/' /etc/ssh/sshd_config

Additional Identifiers

Rule ID: SV-252458r858509_rule

Vulnerability ID: V-252458

Group Title: SRG-OS-000163-GPOS-00072

Expert Comments

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