APPL-26-000051 - The macOS system must configure SSHD ClientAliveInterval to 900.

Warning! Audit Deprecated

This audit has been deprecated and will be removed in a future update.

Information

If SSHD is enabled, it must be configured with the Client Alive Interval set to 900.

This sets a timeout interval in seconds, after which if no data has been received from the client, sshd(8) will send a message through the encrypted channel to request a response from the client.

This setting works in conjunction with ClientAliveCountMax to determine the termination of the connection after the threshold has been reached.

Note: This setting is not intended to manage idle user sessions where there is no input from the client. Its purpose is to look for interruptions in network connectivity and force the session to terminate after the connection appears to be broken.

Note: /etc/ssh/sshd_config will be automatically modified to its original state following any update or major upgrade to the operating system.

Solution

Configure the macOS system to set the SSHD ClientAliveInterval to 900 with the following command:

include_dir=$(/usr/bin/awk '/^Include/ {print $2}' /etc/ssh/sshd_config | /usr/bin/tr -d '*')

if [[ -z $include_dir ]]; then
/usr/bin/sed -i.bk "1s/.*/Include \/etc\/ssh\/sshd_config.d\/\*/" /etc/ssh/sshd_config
fi

/usr/bin/grep -qxF 'clientaliveinterval 900' "${include_dir}01-mscp-sshd.conf" 2>/dev/null || echo "clientaliveinterval 900" >> "${include_dir}01-mscp-sshd.conf"

for file in $(ls ${include_dir}); do
if [[ "$file" == "100-macos.conf" ]]; then
continue
fi
if [[ "$file" == "01-mscp-sshd.conf" ]]; then
break
fi
/bin/mv ${include_dir}${file} ${include_dir}20-${file}
done

Item Details

Audit Name: DISA Apple macOS 26 Tahoe STIG v1r1

Plugin: Unix

Control ID: 8dec9d8695cee90791eff739344c0ea057cdcde8203bf63a7019d9943d8b73a1

Detections

Analytics

APPL-26-000051 - The macOS system must configure SSHD ClientAliveInterval to 900.

Warning! Audit Deprecated

Information

Solution

See Also

Item Details