Описание
Kyverno's PolicyException objects can be created in any namespace by default
Summary
A kyverno ClusterPolicy, ie. "disallow-privileged-containers," can be overridden by the creation of a PolicyException in a random namespace.
Details
By design, PolicyExceptions are consumed from any namespace. Administrators may not recognize that this allows users with privileges to non-kyverno namespaces to create exceptions.
PoC
- Administrator creates "disallow-privileged-containers" ClusterPolicy that applies to resources in the namespace "ubuntu-restricted"
- Cluster user creates a PolicyException object for "disallow-privileged-containers" in namespace "ubuntu-restricted"
- Cluster user creates a pod with a privileged container in "ubuntu-restricted"
- Cluster user escalates to root on the node from the privileged container
Impact
Administrators attempting to enforce cluster security through kyverno policies, but that allow less privileged users to create resources
Пакеты
github.com/kyverno/kyverno
< 1.13.0
1.13.0
Связанные уязвимости
Kyverno is a policy engine designed for Kubernetes. A kyverno ClusterPolicy, ie. "disallow-privileged-containers," can be overridden by the creation of a PolicyException in a random namespace. By design, PolicyExceptions are consumed from any namespace. Administrators may not recognize that this allows users with privileges to non-kyverno namespaces to create exceptions. This vulnerability is fixed in 1.13.0.
