The Photon operating system must implement only approved Message Authentication Codes (MACs) to protect the integrity of remote access sessions.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-258900	PHTN-40-000239	SV-258900r933761_rule		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.

STIG	Date
VMware vSphere 8.0 vCenter Appliance Photon OS 4.0 Security Technical Implementation Guide	2023-10-29

Details

Check Text ( C-62640r933759_chk )
At the command line, run the following command to verify the running configuration of sshd: # sshd -T|&grep -i MACs Example result: macs hmac-sha2-512,hmac-sha2-256 If the output matches the macs in the example result or a subset thereof, this is not a finding. If the output contains any macs not listed in the example result, this is a finding.

Fix Text (F-62549r933760_fix)
Navigate to and open: /etc/ssh/sshd_config Ensure the "MACs" line is uncommented and set to the following: MACs hmac-sha2-512,hmac-sha2-256 At the command line, run the following command: # systemctl restart sshd.service