Nutanix OS must implement cryptography to protect the integrity of remote access sessions by using only HMACs employing FIPS 140-3-approved algorithms.
Overview
| Finding ID | Version | Rule ID | IA Controls | Severity |
| V-279534 | NXAC-OS-000010 | SV-279534r1192285_rule | CCI-001453 | high |
| Description | ||||
| Without cryptographic integrity protections, information can be altered by unauthorized users without detection. Remote access (e.g., RDP) 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. Cryptographic mechanisms used for protecting the integrity of information include, for example, signed hash functions using asymmetric cryptography enabling distribution of the public key to verify the hash information while maintaining the confidentiality of the secret key used to generate the hash. Satisfies: SRG-OS-000250-GPOS-00093, SRG-OS-000393-GPOS-00173, SRG-OS-000394-GPOS-00174, SRG-OS-000125-GPOS-00065 | ||||
| STIG | Date | |||
| Nutanix Acropolis GPOS Security Technical Implementation Guide | 2026-02-24 | |||
Details
Check Text (C-279534r1192285_chk)
Verify Nutanix OS is configured to use approved ciphers.
1. Configure AOS, Prism Central, and Files OS VMs to use only HMACs employing FIPS 140-3-approved algorithms for remote access using the following command.
$ sudo grep -i macs /etc/crypto-policies/back-ends/opensshserver.config
MACS=hmac-sha2-512,hmac-sha2-256,hmac-sha2-512-etm@openssh.com,hmac-sha2-256-etm@openssh.com
2. Verify AHV "Ciphers" configuration using the following command.
$ sudo grep -i ciphers /etc/ssh/sshd_config
Ciphers aes256-ctr
If unapproved ciphers are listed, the "Ciphers" keyword is missing, or the returned line is commented out, this is a finding.
Fix Text (F-83992r1192284_fix)
Configure SSH.
1. For AOS, configure SSH, then restart the SSH for the changes to take effect.
$ sudo salt-call state.sls security/CVM/sshdCVM
$ sudo systemctl restart sshd
2. For Prism Central, configure SSH, then restart the SSH for the changes to take effect.
$ sudo salt-call state.sls security/PCVM/sshdPCVM
$ sudo systemctl restart sshd
3. For Files, configure SSH, then restart the SSH for the changes to take effect.
$ sudo salt-call state.sls security/AFS/sshdAFS
$ sudo systemctl restart sshd
4. For AHV, configure SSH, then restart the SSH for the changes to take effect.
$ sudo salt-call state.sls security/KVM/sshdKVM
$ sudo systemctl restart sshd