STIGQter: STIG Summary: VMware vSphere 8.0 vCenter Appliance Photon OS 4.0 Security Technical Implementation Guide Version: 2 Release: 2 Benchmark Date: 01 Jul 2026:

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

DISA Rule

SV-258900r991554_rule

Vulnerability Number

V-258900

Group Title

SRG-OS-000250-GPOS-00093

Rule Version

PHTN-40-000239

Severity

CAT I

CCI(s)

• CCI-001453 - Implement cryptographic mechanisms to protect the integrity of remote access sessions.

Weight

10

Fix Recommendation

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

Check Contents

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.

Vulnerability Number

V-258900

Documentable

False

Rule Version

PHTN-40-000239

Severity Override Guidance

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.

Check Content Reference

M

Target Key

5569