APPL-14-000057 - The macOS system must limit SSH to FIPS-compliant connections.

Information

SSH must be configured to limit the Ciphers, HostbasedAcceptedAlgorithms, HostKeyAlgorithms, KexAlgorithms, MACs, PubkeyAcceptedAlgorithms, CASignatureAlgorithms to algorithms that are FIPS 140 validated.

FIPS 140-2 is the current standard for validating that mechanisms used to access cryptographic modules utilize authentication that meet federal requirements.

Operating systems utilizing encryption must use FIPS-validated mechanisms for authenticating to cryptographic modules.

Note: For more information on FIPS compliance with the version of SSH included in the macOS, the manual page apple_ssh_and_fips has additional information.

Satisfies: SRG-OS-000033-GPOS-00014,SRG-OS-000120-GPOS-00061,SRG-OS-000250-GPOS-00093,SRG-OS-000396-GPOS-00176,SRG-OS-000424-GPOS-00188,SRG-OS-000478-GPOS-00223

Solution

Configure the macOS system to limit SSH to FIPS-compliant connections with the following command:

fips_ssh_config="Host *
Ciphers [email protected]
HostbasedAcceptedAlgorithms ecdsa-sha2-nistp256,[email protected]
HostKeyAlgorithms ecdsa-sha2-nistp256,[email protected]
KexAlgorithms ecdh-sha2-nistp256
MACs hmac-sha2-256
PubkeyAcceptedAlgorithms ecdsa-sha2-nistp256,[email protected]
CASignatureAlgorithms ecdsa-sha2-nistp256"
/bin/echo "${fips_ssh_config}" > /etc/ssh/ssh_config.d/fips_ssh_config

See Also

https://dl.dod.cyber.mil/wp-content/uploads/stigs/zip/U_Apple_macOS_14_V1R2_STIG.zip

Item Details

Category: ACCESS CONTROL, IDENTIFICATION AND AUTHENTICATION, SYSTEM AND COMMUNICATIONS PROTECTION

References: 800-53|AC-17(2), 800-53|IA-7, 800-53|SC-8(1), 800-53|SC-13, CAT|I, CCI|CCI-000068, CCI|CCI-000803, CCI|CCI-001453, CCI|CCI-002421, CCI|CCI-002450, Rule-ID|SV-259439r945376_rule, STIG-ID|APPL-14-000057, Vuln-ID|V-259439

Plugin: Unix

Control ID: d637ad542b7ab299428458ce393359d153a002028905b9787beb0a71653d3eab