Vulnerabilities (CVE)

Improper input validation in the Kubernetes API server in versions v1.0-1.12 and versions prior to v1.13.12, v1.14.8, v1.15.5, and v1.16.2 allows authorized users to send malicious YAML or JSON payloads, causing the API server to consume excessive CPU or memory, potentially crashing and becoming unavailable. Prior to v1.14.0, default RBAC policy authorized anonymous users to submit requests that could trigger this vulnerability. Clusters upgraded from a version prior to v1.14.0 keep the more per ... Improper input validation in the Kubernetes API server in versions v1.0-1.12 and versions prior to v1.13.12, v1.14.8, v1.15.5, and v1.16.2 allows authorized users to send malicious YAML or JSON payloads, causing the API server to consume excessive CPU or memory, potentially crashing and becoming unavailable. Prior to v1.14.0, default RBAC policy authorized anonymous users to submit requests that could trigger this vulnerability. Clusters upgraded from a version prior to v1.14.0 keep the more permissive policy by default for backwards compatibility.

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A vulnerability exists in F5 BIG-IP Container Ingress Services that may allow excessive permissions to read cluster secrets.  Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.

kubectl does not neutralize escape, meta or control sequences contained in the raw data it outputs to a terminal. This includes but is not limited to the unstructured string fields in objects such as Events.

A SQL Injection vulnerability exists in Esri ArcGIS Server versions 11.3, 11.4 and 11.5 on Windows, Linux and Kubernetes. This vulnerability allows a remote, unauthenticated attacker to execute arbitrary SQL commands via a specific ArcGIS Feature Service operation. Successful exploitation can potentially result in unauthorized access, modification, or deletion of data from the underlying Enterprise Geodatabase.

Kube-proxy on Windows can unintentionally forward traffic to local processes listening on the same port (“spec.ports[*].port”) as a LoadBalancer Service when the LoadBalancer controller does not set the “status.loadBalancer.ingress[].ip” field. Clusters where the LoadBalancer controller sets the “status.loadBalancer.ingress[].ip” field are unaffected.

Default access permissions for Persistent Volumes (PVs) created by the Kubernetes Azure cloud provider in versions 1.6.0 to 1.6.5 are set to "container" which exposes a URI that can be accessed without authentication on the public internet. Access to the URI string requires privileged access to the Kubernetes cluster or authenticated access to the Azure portal.

Kubernetes in OpenShift3 allows remote authenticated users to use the private images of other users should they know the name of said image.

Kubernetes version 1.5.0-1.5.4 is vulnerable to a privilege escalation in the PodSecurityPolicy admission plugin resulting in the ability to make use of any existing PodSecurityPolicy object.

The API server in Kubernetes does not properly check admission control, which allows remote authenticated users to access additional resources via a crafted patched object.

Kubernetes before 1.2.0-alpha.5 allows remote attackers to read arbitrary pod logs via a container name.

Openshift allows remote attackers to gain privileges by updating a build configuration that was created with an allowed type to a type that is not allowed.

A security issue was discovered in Kubernetes where a user that can create pods on Windows nodes may be able to escalate to admin privileges on those nodes. Kubernetes clusters are only affected if they include Windows nodes.

A security issue was discovered in Kubernetes where a user that can create pods on Windows nodes may be able to escalate to admin privileges on those nodes. Kubernetes clusters are only affected if they include Windows nodes.

Users may be able to launch containers that bypass the mountable secrets policy enforced by the ServiceAccount admission plugin when using ephemeral containers. The policy ensures pods running with a service account may only reference secrets specified in the service account’s secrets field. Kubernetes clusters are only affected if the ServiceAccount admission plugin and the `kubernetes.io/enforce-mountable-secrets` annotation are used together with ephemeral containers.

Users may be able to launch containers using images that are restricted by ImagePolicyWebhook when using ephemeral containers. Kubernetes clusters are only affected if the ImagePolicyWebhook admission plugin is used together with ephemeral containers.

A security issue was discovered in Kubernetes where a user that can create pods and persistent volumes on Windows nodes may be able to escalate to admin privileges on those nodes. Kubernetes clusters are only affected if they are using an in-tree storage plugin for Windows nodes.

A security issue was discovered in Kubelet that allows pods to bypass the seccomp profile enforcement. Pods that use localhost type for seccomp profile but specify an empty profile field, are affected by this issue. In this scenario, this vulnerability allows the pod to run in unconfined (seccomp disabled) mode. This bug affects Kubelet.

Users may have access to secure endpoints in the control plane network. Kubernetes clusters are only affected if an untrusted user can modify Node objects and send proxy requests to them. Kubernetes supports node proxying, which allows clients of kube-apiserver to access endpoints of a Kubelet to establish connections to Pods, retrieve container logs, and more. While Kubernetes already validates the proxying address for Nodes, a bug in kube-apiserver made it possible to bypass this validation. B ... Users may have access to secure endpoints in the control plane network. Kubernetes clusters are only affected if an untrusted user can modify Node objects and send proxy requests to them. Kubernetes supports node proxying, which allows clients of kube-apiserver to access endpoints of a Kubelet to establish connections to Pods, retrieve container logs, and more. While Kubernetes already validates the proxying address for Nodes, a bug in kube-apiserver made it possible to bypass this validation. Bypassing this validation could allow authenticated requests destined for Nodes to to the API server's private network.

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Users authorized to list or watch one type of namespaced custom resource cluster-wide can read custom resources of a different type in the same API group without authorization. Clusters are impacted by this vulnerability if all of the following are true: 1. There are 2+ CustomResourceDefinitions sharing the same API group 2. Users have cluster-wide list or watch authorization on one of those custom resources. 3. The same users are not authorized to read another custom resource in the same API gr ... Users authorized to list or watch one type of namespaced custom resource cluster-wide can read custom resources of a different type in the same API group without authorization. Clusters are impacted by this vulnerability if all of the following are true: 1. There are 2+ CustomResourceDefinitions sharing the same API group 2. Users have cluster-wide list or watch authorization on one of those custom resources. 3. The same users are not authorized to read another custom resource in the same API group.

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Windows workloads can run as ContainerAdministrator even when those workloads set the runAsNonRoot option to true.

A security issue was discovered in Kubernetes where a user may be able to create a container with subpath volume mounts to access files & directories outside of the volume, including on the host filesystem.

A security issue was discovered with Kubernetes that could enable users to send network traffic to locations they would otherwise not have access to via a confused deputy attack.

A security issue was discovered in Kubernetes where a user may be able to redirect pod traffic to private networks on a Node. Kubernetes already prevents creation of Endpoint IPs in the localhost or link-local range, but the same validation was not performed on EndpointSlice IPs.

A security issue was discovered in kube-apiserver that could allow node updates to bypass a Validating Admission Webhook. Clusters are only affected by this vulnerability if they run a Validating Admission Webhook for Nodes that denies admission based at least partially on the old state of the Node object. Validating Admission Webhook does not observe some previous fields.

In Kubernetes clusters using Ceph RBD as a storage provisioner, with logging level of at least 4, Ceph RBD admin secrets can be written to logs. This occurs in kube-controller-manager's logs during provisioning of Ceph RBD persistent claims. This affects < v1.19.3, < v1.18.10, < v1.17.13.

In Kubernetes, if the logging level is set to at least 9, authorization and bearer tokens will be written to log files. This can occur both in API server logs and client tool output like kubectl. This affects <= v1.19.3, <= v1.18.10, <= v1.17.13, < v1.20.0-alpha2.

In Kubernetes clusters using a logging level of at least 4, processing a malformed docker config file will result in the contents of the docker config file being leaked, which can include pull secrets or other registry credentials. This affects < v1.19.3, < v1.18.10, < v1.17.13.

In Kubernetes clusters using VSphere as a cloud provider, with a logging level set to 4 or above, VSphere cloud credentials will be leaked in the cloud controller manager's log. This affects < v1.19.3.

As mitigations to a report from 2019 and CVE-2020-8555, Kubernetes attempts to prevent proxied connections from accessing link-local or localhost networks when making user-driven connections to Services, Pods, Nodes, or StorageClass service providers. As part of this mitigation Kubernetes does a DNS name resolution check and validates that response IPs are not in the link-local (169.254.0.0/16) or localhost (127.0.0.0/8) range. Kubernetes then performs a second DNS resolution without validation ... As mitigations to a report from 2019 and CVE-2020-8555, Kubernetes attempts to prevent proxied connections from accessing link-local or localhost networks when making user-driven connections to Services, Pods, Nodes, or StorageClass service providers. As part of this mitigation Kubernetes does a DNS name resolution check and validates that response IPs are not in the link-local (169.254.0.0/16) or localhost (127.0.0.0/8) range. Kubernetes then performs a second DNS resolution without validation for the actual connection. If a non-standard DNS server returns different non-cached responses, a user may be able to bypass the proxy IP restriction and access private networks on the control plane.

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A security issue was discovered in Kubernetes where actors that control the responses of MutatingWebhookConfiguration or ValidatingWebhookConfiguration requests are able to redirect kube-apiserver requests to private networks of the apiserver. If that user can view kube-apiserver logs when the log level is set to 10, they can view the redirected responses and headers in the logs.

The Kubernetes kube-apiserver in versions v1.6-v1.15, and versions prior to v1.16.13, v1.17.9 and v1.18.6 are vulnerable to an unvalidated redirect on proxied upgrade requests that could allow an attacker to escalate privileges from a node compromise to a full cluster compromise.

The Kubelet and kube-proxy components in versions 1.1.0-1.16.10, 1.17.0-1.17.6, and 1.18.0-1.18.3 were found to contain a security issue which allows adjacent hosts to reach TCP and UDP services bound to 127.0.0.1 running on the node or in the node's network namespace. Such a service is generally thought to be reachable only by other processes on the same host, but due to this defeect, could be reachable by other hosts on the same LAN as the node, or by containers running on the same node as the ... The Kubelet and kube-proxy components in versions 1.1.0-1.16.10, 1.17.0-1.17.6, and 1.18.0-1.18.3 were found to contain a security issue which allows adjacent hosts to reach TCP and UDP services bound to 127.0.0.1 running on the node or in the node's network namespace. Such a service is generally thought to be reachable only by other processes on the same host, but due to this defeect, could be reachable by other hosts on the same LAN as the node, or by containers running on the same node as the service.

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The Kubernetes kubelet component in versions 1.1-1.16.12, 1.17.0-1.17.8 and 1.18.0-1.18.5 do not account for disk usage by a pod which writes to its own /etc/hosts file. The /etc/hosts file mounted in a pod by kubelet is not included by the kubelet eviction manager when calculating ephemeral storage usage by a pod. If a pod writes a large amount of data to the /etc/hosts file, it could fill the storage space of the node and cause the node to fail.

The Kubernetes kube-controller-manager in versions v1.0-1.14, versions prior to v1.15.12, v1.16.9, v1.17.5, and version v1.18.0 are vulnerable to a Server Side Request Forgery (SSRF) that allows certain authorized users to leak up to 500 bytes of arbitrary information from unprotected endpoints within the master's host network (such as link-local or loopback services).

Kubernetes API server in all versions allow an attacker who is able to create a ClusterIP service and set the spec.externalIPs field, to intercept traffic to that IP address. Additionally, an attacker who is able to patch the status (which is considered a privileged operation and should not typically be granted to users) of a LoadBalancer service can set the status.loadBalancer.ingress.ip to similar effect.

The Kubernetes API server component in versions prior to 1.15.9, 1.16.0-1.16.6, and 1.17.0-1.17.2 has been found to be vulnerable to a denial of service attack via successful API requests.

The Kubelet component in versions 1.15.0-1.15.9, 1.16.0-1.16.6, and 1.17.0-1.17.2 has been found to be vulnerable to a denial of service attack via the kubelet API, including the unauthenticated HTTP read-only API typically served on port 10255, and the authenticated HTTPS API typically served on port 10250.

Cloud Native Computing Foundation (CNCF) CNI (Container Networking Interface) 0.7.4 has a network firewall misconfiguration which affects Kubernetes. The CNI 'portmap' plugin, used to setup HostPorts for CNI, inserts rules at the front of the iptables nat chains; which take precedence over the KUBE- SERVICES chain. Because of this, the HostPort/portmap rule could match incoming traffic even if there were better fitting, more specific service definition rules like NodePorts later in the chain. Th ... Cloud Native Computing Foundation (CNCF) CNI (Container Networking Interface) 0.7.4 has a network firewall misconfiguration which affects Kubernetes. The CNI 'portmap' plugin, used to setup HostPorts for CNI, inserts rules at the front of the iptables nat chains; which take precedence over the KUBE- SERVICES chain. Because of this, the HostPort/portmap rule could match incoming traffic even if there were better fitting, more specific service definition rules like NodePorts later in the chain. The issue is fixed in CNI 0.7.5 and Kubernetes 1.11.9, 1.12.7, 1.13.5, and 1.14.0.

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The Kubernetes API Server component in versions 1.1-1.14, and versions prior to 1.15.10, 1.16.7 and 1.17.3 allows an authorized user who sends malicious YAML payloads to cause the kube-apiserver to consume excessive CPU cycles while parsing YAML.

The Kubernetes kube-controller-manager in versions v1.0-v1.17 is vulnerable to a credential leakage via error messages in mount failure logs and events for AzureFile and CephFS volumes.