Title

NixOS must implement multifactor authentication for remote access to privileged accounts in such a way that one of the factors is provided by a device separate from the system gaining access. (Cat II impact)

Discussion

Using an authentication device, such as a CAC or token that is separate from the information system, ensures that even if the information system is compromised, that compromise will not affect credentials stored on the authentication device. Multifactor solutions that require devices separate from information systems gaining access include, for example, hardware tokens providing time-based or challenge-response authenticators and smart cards such as the U.S. Government Personal Identity Verification (PIV) card and the DOD Common Access Card (CAC). A privileged account is defined as an information system account with authorizations of a privileged user. Remote access is access to DOD nonpublic information systems by an authorized user (or an information system) communicating through an external, nonorganization-controlled network. Remote access methods include, for example, dial-up, broadband, and wireless. This requirement only applies to components where this is specific to the function of the device or has the concept of an organizational user (e.g., VPN, proxy capability). This does not apply to authentication for the purpose of configuring the device itself (management). This requires further clarification from NIST. Satisfies: SRG-OS-000375-GPOS-00160, SRG-OS-000068-GPOS-00036, SRG-OS-000376-GPOS-00161, SRG-OS-000377-GPOS-00162, SRG-OS-000705-GPOS-00150

Check Content

Verify NixOS provides authentication via the security and pam modules with the following command: $ cat /etc/nixos/configuration.nix | grep -A 1 security.pam.p11 security.pam.p11.enable = true; If security.pam.p11.enable is not. "true", is not present or is commented out, this is a finding.

Fix Text

Configure the NixOS operating system to use strong authentication when establishing nonlocal maintenance and diagnostic sessions. Add or modify the following line to /etc/nixos/configuration.nix: security.pam.p11.enable = true; Rebuild the NixOS configuration with the following command: $ sudo nixos-rebuild switch

Additional Identifiers

Rule ID: SV-268177r1039419_rule

Vulnerability ID: V-268177

Group Title: SRG-OS-000375-GPOS-00160

Expert Comments

CCIs tied to check.

Controls tied to check. These are derived from the CCIs shown above.