Gardener implements the automated management and operation of Kubernetes clusters as a service. A security vulnerability was discovered in Gardener prior to versions 1.116.4, 1.117.5, 1.118.2, and 1.119.0 that could allow a user with administrative privileges for a Gardener project to obtain control over the seed cluster(s) where their shoot clusters are managed. This CVE affects all Gardener installations no matter of the public cloud provider(s) used for the seed clusters/shoot clusters. `gardener/gardener` (`gardenlet`) is the affected component. Versions 1.116.4, 1.117.5, 1.118.2, and 1.119.0 fix the issue.

gardener

Gardener External DNS Management is an environment to manage external DNS entries for a kubernetes cluster. A security vulnerability was discovered in Gardener's External DNS Management prior to version 0.23.6 that could allow a user with administrative privileges for a Gardener project or a user with administrative privileges for a shoot cluster, including administrative privileges for a single namespace of the shoot cluster, to obtain control over the seed cluster where the shoot cluster is managed. This CVE affects all Gardener installations no matter of the public cloud provider(s) used for the seed clusters/shoot clusters. The affected component is `gardener/external-dns-management`. The `external-dns-management` component may also be deployed on the seeds by the `gardener/gardener-extension-shoot-dns-service` extension when the extension is enabled. In this case, all versions of the `shoot-dns-service` extension `<= v1.60.0` are affected by this vulnerability. Version 0.23.6 of Gardener External DNS Management fixes the issue.

In Gardener before 0.20.0, incorrect access control in seed clusters allows information disclosure by sending HTTP GET requests from one's own shoot clusters to foreign shoot clusters. This occurs because traffic from shoot to seed via the VPN endpoint is not blocked.

gardener

Following the Gardener architecture, the Kubernetes apiserver of a Gardener managed shoot cluster resides in the corresponding seed cluster. Due to missing network isolation a shoot's apiserver can access services/endpoints in the private network of its corresponding seed cluster. Combined with other minor Kubernetes security issues, the missing network isolation theoretically can lead to compromise other shoot or seed clusters in the "Gardener" context. The issue is rated high due to the high impact of a potential exploitation in "Gardener" context. This was fixed in Gardener release 0.12.4.

gardener