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The macOS system must configure SSHD ClientAliveInterval to 900.

Overview

Finding IDVersionRule IDIA ControlsSeverity
V-268435APPL-15-000051SV-268435r1131188_ruleCCI-001133medium
Description
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.
STIGDate
Apple macOS 15 (Sequoia) Security Technical Implementation Guide2026-02-06

Related Frameworks

1 mapping across 4 frameworks
SCF0 mappings

No source states a mapping between these directly.

Also reachable in 3 hops (1) derived by us, not asserted by any source

Each of these is a route we composed by chaining published mappings. No publisher states a relationship between the two endpoints.

NET-07Network Connection Termination
1.00
NIST 800-530 mappings

No source states a mapping between these directly.

Also reachable in 2 hops (24) derived by us, not asserted by any source

Each of these is a route we composed by chaining published mappings. No publisher states a relationship between the two endpoints.

AC-11Device Lock
1.00
AC-11(1)Pattern-hiding Displays
1.00
AC-12Session Termination
1.00
AC-12(2)Termination Message
1.00
AC-2(1)Automated System Account Management
1.00
AC-2(11)Usage Conditions
1.00
AC-2(2)Automated Temporary and Emergency Account Management
1.00
AC-2(3)Disable Accounts
1.00
AC-2(4)Automated Audit Actions
1.00
AC-7Unsuccessful Logon Attempts
1.00

+14 more (top 10 by confidence shown)

NIST 800-1710 mappings

No source states a mapping between these directly.

Also reachable in 3 hops (1) derived by us, not asserted by any source

Each of these is a route we composed by chaining published mappings. No publisher states a relationship between the two endpoints.

3.13.9
1.00
CCI1 mapping
CCI-001133
1.00

Details

Check Text (C-268435r1131188_chk)

Verify the macOS system is configured to set the SSHD ClientAliveInterval to 900 with the following command: /usr/sbin/sshd -G | /usr/bin/awk '/clientaliveinterval/{print $2}' If the result is not "900", this is a finding.

Fix Text (F-72366r1131187_fix)

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