The Kubernetes API server mistakenly allows access to a cluster-scoped custom resource if the request is made as if the resource were namespaced. Authorizations for the resource accessed in this manner are enforced using roles and role bindings within the namespace, meaning that a user with access only to a resource in one namespace could create, view update or delete the cluster-scoped resource (according to their namespace role privileges).

A flaw was found in HTTP/2. Using HEADER frames with invalid HTTP headers and queuing of response RSTSTREAM frames, an attacker could cause a flood resulting in unbounded memory growth. The highest threat from this vulnerability is to system availability.

A flaw was found kubernetes. The parsing of YAML manifests by the Kubernetes API server could lead to a denial-of-service attack leaving it vulnerable to an instance of a "billion laughs" attack. The highest threat from this vulnerability is to system availability.

A flaw was discovered in the HPACK decoder of haproxy before 1.8.14, that is used for HTTP/2. An out-of-bounds read access in hpackvalididx() resulted in a remote crash and denial of service. According to the report, there is no risk of escalation or code execution.

A third issue was discovered with the Kubernetes kubectl cp command that could enable a directory traversal such that a malicious container could replace or create files on a user’s workstation. The vulnerability is a client-side defect and requires user interaction to be exploited.

This vulnerability allows a malicious container to cause a file to be created or replaced on the client computer when the client uses the kubectl cp operation. The vulnerability is a client-side defect and requires user interaction to be exploited.

Upstream Issue:

https://github.com/kubernetes/kubernetes/issues/80984

External References:

https://groups.google.com/forum/#!topic/kubernetes-security-discuss/Vf31dXp0EJc