STIGQter 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 disable systemd fallback DNS.

DISA Rule

SV-258898r991589_rule

Vulnerability Number

V-258898

Group Title

SRG-OS-000480-GPOS-00227

Rule Version

PHTN-40-000236

Severity

CAT II

CCI(s)

Weight

10

Fix Recommendation

Navigate to and open:

/etc/systemd/resolved.conf

Add or update the "FallbackDNS" entry to the following:

FallbackDNS=

Restart the Systemd resolved service by running the following command:

# systemctl restart systemd-resolved

Note: If this option is not given, a compiled-in list of DNS servers is used instead, which is undesirable.

Check Contents

At the command line, run the following command to verify systemd fallback DNS is disabled:

# resolvectl status | grep '^Fallback DNS'

If the output indicates that Fallback DNS servers are configured, this is a finding.

Vulnerability Number

V-258898

Documentable

False

Rule Version

PHTN-40-000236

Severity Override Guidance

At the command line, run the following command to verify systemd fallback DNS is disabled:

# resolvectl status | grep '^Fallback DNS'

If the output indicates that Fallback DNS servers are configured, this is a finding.

Check Content Reference

M

Target Key

5569