CNF-21212: RAN Hardening (5.0) - PAM Empty Passwords (H2)

[sebrandon1]

Summary

Adds MachineConfig to remove the nullok option from PAM authentication on both master and worker nodes.

This addresses a HIGH severity finding from the ACSC Essential Eight compliance profile — the no_empty_passwords rule requires preventing authentication with empty passwords.

• Deploys the correct RHCOS 9 /etc/pam.d/system-auth with nullok removed
• Uses the actual RHCOS 9 PAM stack (not the broken operator-generated RHEL 8 template)
• Separate master and worker MachineConfig files

Upstream

We have an open PR to fix this in the RHCOS base image so this MachineConfig remediation would no longer be needed:

• coreos/rhel-coreos-config#255 — Disable empty password authentication via authselect without-nullok

We also have an upstream fix for the broken compliance-operator remediation:

• ComplianceAsCode/content#14602 — Fix no_empty_passwords remediation for RHCOS 9

Remediation Group

• H2: PAM Empty Passwords

Files

• 75-pam-auth-high-master.yaml
• 75-pam-auth-high-worker.yaml

Verification

After applying to a cluster, verify with:

oc debug node/ -- chroot /host grep nullok /etc/pam.d/system-auth
# Expected: no output (nullok removed)

Jira

• Story: CNF-21212
• Epic: CNF-22573 (RAN Hardening for 5.0)

Supersedes #736 — migrated from compliance/4.22/* to compliance/5.0/* branch naming.

OCP 5.0 Verification (2026-06-22)

Cluster: cnfdt16 — OCP 5.0.0-0.nightly-2026-06-18-000016, RHCOS 10.2

Finding: Hardening still needed. RHCOS 10 authselect templates still ship with nullok.

$ grep nullok /etc/authselect/system-auth
auth        sufficient    pam_unix.so nullok
password    sufficient    pam_unix.so yescrypt shadow nullok use_authtok

$ grep nullok /etc/authselect/password-auth
auth        sufficient    pam_unix.so nullok
password    sufficient    pam_unix.so yescrypt shadow nullok use_authtok

$ authselect current
Profile ID: local
Enabled features: None     # without-nullok NOT enabled

The without-nullok authselect feature exists but is not enabled by default. Upstream PRs (coreos/rhel-coreos-config#255, ComplianceAsCode/content#14602) remain open.

[openshift-ci-robot]

@sebrandon1: This pull request references CNF-21212 which is a valid jira issue.

Warning: The referenced jira issue has an invalid target version for the target branch this PR targets: expected the story to target the "5.0.0" version, but no target version was set.

Details

In response to this:

Summary

Adds MachineConfig to remove the nullok option from PAM authentication on both master and worker nodes.

This addresses HIGH severity E8 compliance check rhcos4-e8-no-empty-passwords which requires preventing authentication with empty passwords.

• Deploys the correct RHCOS 9 /etc/pam.d/system-auth with nullok removed
• Uses the actual RHCOS 9 PAM stack (not the broken operator-generated RHEL 8 template)
• Separate master and worker MachineConfig files

Upstream

We have an open PR to fix this in the RHCOS base image so this MachineConfig remediation would no longer be needed:

• coreos/rhel-coreos-config#255 — Disable empty password authentication via authselect without-nullok

We also have an upstream fix for the broken compliance-operator remediation:

• ComplianceAsCode/content#14602 — Fix no_empty_passwords remediation for RHCOS 9

Remediation Group

• H2: PAM Empty Passwords

Files

• 75-pam-auth-high-master.yaml
• 75-pam-auth-high-worker.yaml

Verification

After applying to a cluster, verify with:

oc debug node/ -- chroot /host grep nullok /etc/pam.d/system-auth
# Expected: no output (nullok removed)

Jira

• Story: CNF-21212
• Epic: CNF-22573 (RAN Hardening for 5.0)

Supersedes #736 — migrated from compliance/4.22/* to compliance/5.0/* branch naming.

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the openshift-eng/jira-lifecycle-plugin repository.

[openshift-ci]

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📒 Files selected for processing (2)

• telco-ran/configuration/kube-compare-reference/informational/hardening/75-pam-auth-high-master.yaml
• telco-ran/configuration/kube-compare-reference/informational/hardening/75-pam-auth-high-worker.yaml

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[openshift-ci-robot]

@sebrandon1: This pull request references CNF-21212 which is a valid jira issue.

Warning: The referenced jira issue has an invalid target version for the target branch this PR targets: expected the story to target the "5.0.0" version, but no target version was set.

Details

In response to this:

Summary

Adds MachineConfig to remove the nullok option from PAM authentication on both master and worker nodes.

This addresses HIGH severity E8 compliance check rhcos4-e8-no-empty-passwords which requires preventing authentication with empty passwords.

• Deploys the correct RHCOS 9 /etc/pam.d/system-auth with nullok removed
• Uses the actual RHCOS 9 PAM stack (not the broken operator-generated RHEL 8 template)
• Separate master and worker MachineConfig files

Upstream

We have an open PR to fix this in the RHCOS base image so this MachineConfig remediation would no longer be needed:

• coreos/rhel-coreos-config#255 — Disable empty password authentication via authselect without-nullok

We also have an upstream fix for the broken compliance-operator remediation:

• ComplianceAsCode/content#14602 — Fix no_empty_passwords remediation for RHCOS 9

Remediation Group

• H2: PAM Empty Passwords

Files

• 75-pam-auth-high-master.yaml
• 75-pam-auth-high-worker.yaml

Verification

After applying to a cluster, verify with:

oc debug node/ -- chroot /host grep nullok /etc/pam.d/system-auth
# Expected: no output (nullok removed)

Jira

• Story: CNF-21212
• Epic: CNF-22573 (RAN Hardening for 5.0)

Supersedes #736 — migrated from compliance/4.22/* to compliance/5.0/* branch naming.

OCP 5.0 Verification (2026-06-22)

Cluster: cnfdt16 — OCP 5.0.0-0.nightly-2026-06-18-000016, RHCOS 10.2

Finding: Hardening still needed. RHCOS 10 authselect templates still ship with nullok.

$ grep nullok /etc/authselect/system-auth
auth        sufficient    pam_unix.so nullok
password    sufficient    pam_unix.so yescrypt shadow nullok use_authtok

$ grep nullok /etc/authselect/password-auth
auth        sufficient    pam_unix.so nullok
password    sufficient    pam_unix.so yescrypt shadow nullok use_authtok

$ authselect current
Profile ID: local
Enabled features: None     # without-nullok NOT enabled

The without-nullok authselect feature exists but is not enabled by default. Upstream PRs (coreos/rhel-coreos-config#255, ComplianceAsCode/content#14602) remain open.

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the openshift-eng/jira-lifecycle-plugin repository.

[openshift-ci-robot]

@sebrandon1: This pull request references CNF-21212 which is a valid jira issue.

Warning: The referenced jira issue has an invalid target version for the target branch this PR targets: expected the story to target the "5.0.0" version, but no target version was set.

Details

In response to this:

Summary

Adds MachineConfig to remove the nullok option from PAM authentication on both master and worker nodes.

This addresses a HIGH severity finding from the ACSC Essential Eight compliance profile — the no_empty_passwords rule requires preventing authentication with empty passwords.

• Deploys the correct RHCOS 9 /etc/pam.d/system-auth with nullok removed
• Uses the actual RHCOS 9 PAM stack (not the broken operator-generated RHEL 8 template)
• Separate master and worker MachineConfig files

Upstream

We have an open PR to fix this in the RHCOS base image so this MachineConfig remediation would no longer be needed:

• coreos/rhel-coreos-config#255 — Disable empty password authentication via authselect without-nullok

We also have an upstream fix for the broken compliance-operator remediation:

• ComplianceAsCode/content#14602 — Fix no_empty_passwords remediation for RHCOS 9

Remediation Group

• H2: PAM Empty Passwords

Files

• 75-pam-auth-high-master.yaml
• 75-pam-auth-high-worker.yaml

Verification

After applying to a cluster, verify with:

oc debug node/ -- chroot /host grep nullok /etc/pam.d/system-auth
# Expected: no output (nullok removed)

Jira

• Story: CNF-21212
• Epic: CNF-22573 (RAN Hardening for 5.0)

Supersedes #736 — migrated from compliance/4.22/* to compliance/5.0/* branch naming.

OCP 5.0 Verification (2026-06-22)

Cluster: cnfdt16 — OCP 5.0.0-0.nightly-2026-06-18-000016, RHCOS 10.2

Finding: Hardening still needed. RHCOS 10 authselect templates still ship with nullok.

$ grep nullok /etc/authselect/system-auth
auth        sufficient    pam_unix.so nullok
password    sufficient    pam_unix.so yescrypt shadow nullok use_authtok

$ grep nullok /etc/authselect/password-auth
auth        sufficient    pam_unix.so nullok
password    sufficient    pam_unix.so yescrypt shadow nullok use_authtok

$ authselect current
Profile ID: local
Enabled features: None     # without-nullok NOT enabled

The without-nullok authselect feature exists but is not enabled by default. Upstream PRs (coreos/rhel-coreos-config#255, ComplianceAsCode/content#14602) remain open.

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the openshift-eng/jira-lifecycle-plugin repository.