| Group
Guide to the Secure Configuration of Red Hat OpenShift Container Platform 4
Group contains 6 groups and 12 rules |
| Group
OpenShift Settings
Group contains 5 groups and 12 rules |
[ref]
Each section of this configuration guide includes information about the default configuration
of an OpenShift cluster and a set of recommendations for hardening the configuration. For each
hardening recommendation, information on how to implement the control and/or how to verify or audit
the control is provided. In some cases, remediation information is also provided.
Many of the settings in the hardening guide are in place by default. The audit information for these
settings is provided in order to verify that the cluster admininstrator has not made changes that
would be less secure than the OpenShift defaults. A small number of items require configuration.
Finally, there are some recommendations that require decisions by the system operator, such as audit
log size, retention, and related settings. |
| Group
OpenShift Kube API Server
Group contains 2 rules |
[ref]
This section contains recommendations for kube-apiserver configuration. |
Rule
Configure the Encryption Provider Cipher
[ref] | To ensure the correct cipher, set the encryption type aescbc in the
apiserver object which configures the API server itself.
spec:
encryption:
type: aescbc
For more information, follow
the relevant documentation. Warning:
This rule's check operates on the cluster configuration dump.
Therefore, you need to use a tool that can query the OCP API, retrieve the /apis/config.openshift.io/v1/apiservers/cluster API endpoint to the local /kubernetes-api-resources/apis/config.openshift.io/v1/apiservers/cluster file. | | Rationale: | aescbc is currently the strongest encryption provider, it should
be preferred over other providers.
| | Severity: | medium | | Rule ID: | xccdf_org.ssgproject.content_rule_api_server_encryption_provider_cipher | | Identifiers and References | References:
CIP-003-3 R4.2, SC-28, SC-28(1), 1.2.34 | |
|
Rule
Use Strong Cryptographic Ciphers on the API Server
[ref] | To ensure that the API Server is configured to only use strong
cryptographic ciphers, verify the openshift-kube-apiserver
configmap contains the following set of ciphers, with no additions:
"servingInfo":{
...
"cipherSuites": [
"TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256",
"TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256",
"TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384",
"TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384",
"TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256",
"TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256",
],
...
Warning:
This rule's check operates on the cluster configuration dump.
Therefore, you need to use a tool that can query the OCP API, retrieve the /api/v1/namespaces/openshift-kube-apiserver/configmaps/config API endpoint to the local /kubernetes-api-resources/api/v1/namespaces/openshift-kube-apiserver/configmaps/config file. Warning:
Once configured, API Server clients that cannot support modern
cryptographic ciphers will not be able to make connections to the API
server. | | Rationale: | TLS ciphers have had a number of known vulnerabilities and weaknesses,
which can reduce the protection provided. By default, OpenShift supports
a number of TLS ciphersuites including some that have security concerns,
weakening the protection provided. | | Severity: | medium | | Rule ID: | xccdf_org.ssgproject.content_rule_api_server_tls_cipher_suites | | Identifiers and References | References:
1.2.35 | |
|
| Group
Authentication
Group contains 1 rule |
[ref]
In cloud workloads, there are many ways to create and configure
to multiple authentication services. Some of these authentication
methods by not be secure or common methodologies, or they may not
be secure by default. This section introduces mechanisms for
configuring authentication systems to OpenShift. |
Rule
Do Not Use htpasswd-based IdP
[ref] |
For users to interact with OpenShift Container Platform, they must first
authenticate to the cluster. The authentication layer identifies the user
associated with requests to the OpenShift Container Platform API. The
authorization layer then uses information about the requesting user to
determine if the request is allowed.
Understanding authentication | Authentication | OpenShift Container Platform
The OpenShift Container Platform includes a built-in OAuth server for
token-based authentication. Developers and administrators obtain OAuth
access tokens to authenticate themselves to the API. It is recommended for
an administrator to configure OAuth to specify an identity provider after
the cluster is installed. User access to the cluster is managed through the
identity provider.
Understanding identity provider configuration | Authentication | OpenShift Container Platform
However, not all Identity Providers supported by OpenShift provide the same
level of capabilities. As an example, the htpasswd Identity Provider only
checks the username and password match and provides no means of 2FA, account
lockout or notification mechanism. This rule therefore only allows a subset
of identity providers.
Warning:
This rule's check operates on the cluster configuration dump.
Therefore, you need to use a tool that can query the OCP API, retrieve the /apis/config.openshift.io/v1/oauths/cluster API endpoint to the local /kubernetes-api-resources/apis/config.openshift.io/v1/oauths/cluster file. | | Rationale: |
With any authentication mechanism the ability to revoke credentials if they
are compromised or no longer required, is a key control. Kubernetes client
certificate authentication does not allow for this due to a lack of support
for certificate revocation.
OpenShift's built-in OAuth server allows credential revocation by relying on
the Identity provider, as well as giving the administrators the ability to
revoke any tokens given to a specific user.
In addition, using an external Identity provider allows for setting up notifications
on account creation or deletion, multi-factor authentication, disabling inactive
accounts or other features required by different compliance standards.
| | Severity: | medium | | Rule ID: | xccdf_org.ssgproject.content_rule_ocp_idp_no_htpasswd | | Identifiers and References | Identifiers:
CCE-84209-6 References:
CIP-003-3 R5.1.1, CIP-003-3 R5.3, CIP-004-3 R2.2.2, CIP-004-3 R2.2.3, CIP-004-3 R2.3, CIP-007-3 R.1.3, CIP-007-3 R5, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, CIP-007-3 R5.1.3, CIP-007-3 R5.2, CIP-007-3 R5.2.1, CIP-007-3 R5.2.3, CIP-007-3 R5.3.1, CIP-007-3 R5.3.2, CIP-007-3 R5.3.3, AC-2(1), AC-2(2), AC-2(3), AC-2(4), AC-2(7), AC-2(8), AC-7, IA-2, IA-2(1), IA-2(2), IA-2(3), IA-2(5), IA-2(12), IA-5(4) | |
|
| Group
Role-based Acess Control
Group contains 3 rules |
[ref]
Role-based access control (RBAC) objects determine
whether a user is allowed to perform a given action
within a project.
Cluster administrators can use the cluster roles and
bindings to control who has various access levels to
the OpenShift Container Platform platform itself
and all projects.
Developers can use local roles and bindings to control
who has access to their projects. Note that authorization
is a separate step from authentication, which is more
about determining the identity of who is taking the action. |
Rule
Ensure that the cluster-admin role is only used where required
[ref] | The RBAC role cluster-admin provides wide-ranging powers over the
environment and should be used only where and when needed. | | Rationale: | Kubernetes provides a set of default roles where RBAC is used. Some of these
roles such as cluster-admin provide wide-ranging privileges which should
only be applied where absolutely necessary. Roles such as cluster-admin
allow super-user access to perform any action on any resource. When used in
a ClusterRoleBinding, it gives full control over every resource in the
cluster and in all namespaces. When used in a RoleBinding, it gives full
control over every resource in the rolebinding's namespace, including the
namespace itself. | | Severity: | medium | | Rule ID: | xccdf_org.ssgproject.content_rule_rbac_limit_cluster_admin | | Identifiers and References | References:
CIP-003-3 R6, CIP-004-3 R3, CIP-007-3 R6.1, CM-6, CM-6(1), 5.1.1 | |
|
Rule
Minimize Access to Pod Creation
[ref] | The ability to create pods in a namespace can provide a
number of opportunities for privilege escalation. Where
applicable, remove create access to pod
objects in the cluster. | | Rationale: | The ability to create pods in a cluster opens up the cluster
for privilege escalation. | | Severity: | medium | | Rule ID: | xccdf_org.ssgproject.content_rule_rbac_pod_creation_access | | Identifiers and References | References:
CIP-003-3 R6, CIP-004-3 R3, CIP-007-3 R6.1, CM-6, CM-6(1), 5.1.4 | |
|
Rule
Minimize Wildcard Usage in Cluster and Local Roles
[ref] | Kubernetes Cluster and Local Roles provide access to resources
based on sets of objects and actions that can be taken on
those objects. It is possible to set either of these using a
wildcard * which matches all items. This violates the
principle of least privilege and leaves a cluster in a more
vulnerable state to privilege abuse. | | Rationale: | The principle of least privilege recommends that users are
provided only the access required for their role and nothing
more. The use of wildcard rights grants is likely to provide
excessive rights to the Kubernetes API. | | Severity: | medium | | Rule ID: | xccdf_org.ssgproject.content_rule_rbac_wildcard_use | | Identifiers and References | References:
CIP-003-3 R6, CIP-004-3 R3, CIP-007-3 R6.1, CM-6, CM-6(1), 5.1.3 | |
|
| Group
OpenShift - Registry Security Practices
Group contains 2 rules |
[ref]
Contains evaluations for OpenShift registry security practices, and cluster-wide registry configuration. |
Rule
Allowed registries are configured
[ref] | The configuration registrySources.allowedRegistries determines the
permitted registries that the OpenShift container runtime can access for builds
and pods. This configuration setting ensures that all registries other than
those specified are blocked.
You can set the allowed repositories by applying the following manifest using
oc patch , e.g. if you save the following snippet to
/tmp/allowed-registries-patch.yaml
spec:
registrySources:
allowedRegistries:
- my-trusted-registry.internal.example.com
you would call
oc patch image.config.openshift.io cluster --patch="$(cat /tmp/allowed-registries-patch.yaml)" --type=merge Warning:
This rule's check operates on the cluster configuration dump.
Therefore, you need to use a tool that can query the OCP API, retrieve the /apis/config.openshift.io/v1/images/cluster API endpoint to the local /kubernetes-api-resources/apis/config.openshift.io/v1/images/cluster file. | | Rationale: | Allowed registries should be configured to restrict the registries that the
OpenShift container runtime can access, and all other registries should be
blocked. | | Severity: | medium | | Rule ID: | xccdf_org.ssgproject.content_rule_ocp_allowed_registries | | Identifiers and References | | |
|
Rule
Allowed registries for import are configured
[ref] | The configuration allowedRegistriesForImport limits the container
image registries from which normal users may import images. This is important
to control, as a user who can stand up a malicious registry can then import
content which claims to include the SHAs of legimitate content layers.
You can set the allowed repositories for import by applying the following
manifest using oc patch , e.g. if you save the following snippet to
/tmp/allowed-import-registries-patch.yaml
spec:
allowedRegistriesForImport:
- domainName: my-trusted-registry.internal.example.com
insecure: false
you would call
oc patch image.config.openshift.io cluster --patch="$(cat /tmp/allowed-import-registries-patch.yaml)" --type=merge Warning:
This rule's check operates on the cluster configuration dump.
Therefore, you need to use a tool that can query the OCP API, retrieve the /apis/config.openshift.io/v1/images/cluster API endpoint to the local /kubernetes-api-resources/apis/config.openshift.io/v1/images/cluster file. | | Rationale: | Allowed registries for import should be specified to limit the registries
from which users may import images. | | Severity: | medium | | Rule ID: | xccdf_org.ssgproject.content_rule_ocp_allowed_registries_for_import | | Identifiers and References | | |
|
| Group
Security Context Constraints (SCC)
Group contains 4 rules |
[ref]
Similar to the way that RBAC resources control user access,
administrators can use Security Context Constraints (SCCs)
to control permissions for pods. These permissions include
actions that a pod, a collection of containers, can perform
and what resources it can access. You can use SCCs to define
a set of conditions that a pod must run with in order to be
accepted into the system. |
Rule
Limit Container Capabilities
[ref] | Containers should not enable more capabilites than needed as this
opens the door for malicious use. To enable only the
required capabilities, the appropriate Security Context Constraints (SCCs)
should set capabilities as a list in allowedCapabilities. Warning:
This rule's check operates on the cluster configuration dump.
Therefore, you need to use a tool that can query the OCP API, retrieve the following:
/apis/security.openshift.io/v1/securitycontextconstraints
API endpoint, filter with with the jq utility using the following filter
[.items[] | select(.metadata.name != "privileged")] | map(.allowedCapabilities == null)
and persist it to the local
/kubernetes-api-resources/apis/security.openshift.io/v1/securitycontextconstraints#1b1d5c3b8fa7fe90ab23ee8792e142cd7464b5c1713df0b5822ca4a94e5ab423
file.
| | Rationale: | By default, containers run with a default set of capabilities as assigned
by the Container Runtime which can include dangerous or highly privileged
capabilities. Capabilities should be dropped unless absolutely critical for
the container to run software as added capabilities that are not required
allow for malicious containers or attackers. | | Severity: | medium | | Rule ID: | xccdf_org.ssgproject.content_rule_scc_limit_container_allowed_capabilities | | Identifiers and References | References:
CIP-003-3 R6, CIP-004-3 R3, CIP-007-3 R6.1, CM-6, CM-6(1), 5.2.8 | |
|
Rule
Limit Containers Ability to Escalate Privileges
[ref] | Containers should be limited to only the privileges required
to run and should not be allowed to escalate their privileges.
To prevent containers from escalating privileges,
the appropriate Security Context Constraints (SCCs)
should set allowPrivilegeEscalation to false. | | Rationale: | Privileged containers have access to more of the Linux Kernel
capabilities and devices. If a privileged container were
compromised, an attacker would have full access to the container
and host. | | Severity: | medium | | Rule ID: | xccdf_org.ssgproject.content_rule_scc_limit_privilege_escalation | | Identifiers and References | Identifiers:
CCE-83447-3 References:
CIP-003-3 R6, CIP-004-3 R3, CIP-007-3 R6.1, CM-6, CM-6(1), 5.2.5 | |
|
Rule
Limit Privileged Container Use
[ref] | Containers should be limited to only the privileges required
to run. To prevent containers from running as privileged containers,
the appropriate Security Context Constraints (SCCs) should set
allowPrivilegedContainer to false. | | Rationale: | Privileged containers have access to all Linux Kernel
capabilities and devices. If a privileged container were
compromised, an attacker would have full access to the container
and host. | | Severity: | medium | | Rule ID: | xccdf_org.ssgproject.content_rule_scc_limit_privileged_containers | | Identifiers and References | References:
CIP-003-3 R6, CIP-004-3 R3, CIP-007-3 R6.1, CM-6, CM-6(1), 5.2.1 | |
|
Rule
Limit Container Running As Root User
[ref] | Containers should be limited to only the privileges required
to run and should very rarely be run as root user. To prevent
containers from running as root user,
the appropriate Security Context Constraints (SCCs) should set
allowPrivilegedContainer to false. | | Rationale: | Privileged containers have access to all Linux Kernel
capabilities and devices. If a privileged container were
compromised, an attacker would have full access to the container
and host. | | Severity: | medium | | Rule ID: | xccdf_org.ssgproject.content_rule_scc_limit_root_containers | | Identifiers and References | References:
CIP-003-3 R6, CIP-004-3 R3, CIP-007-3 R6.1, CM-6, CM-6(1), 5.2.6 | |
|