[Security Advisory] CVE-2020-8551, CVE-2020-8552: Denial of service (Medium)

[Tim Allclair]

Hello Kubernetes Community,

Two security issues were discovered in Kubernetes that could lead to a recoverable denial of service.

CVE-2020-8551 affects the kubelet, and has been rated Medium (CVSS:3.0/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L).

CVE-2020-8552 affects the API server, and has also been rated Medium (CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L).

Am I vulnerable?

If an attacker can make an authorized resource request to an unpatched API server (see below), then you may be vulnerable to CVE-2020-8552. If an attacker can make an authorized request to an unpatched kubelet, then you may be vulnerable to CVE-2020-8551.

Affected Versions

CVE-2020-8551 affects:

• kubelet v1.17.0 - v1.17.2
• kubelet v1.16.0 - v1.16.6
• kubelet v1.15.0 - v1.15.10\
• kubelets prior to v1.15.0 are unaffected

CVE-2020-8552 affects:

• kube-apiserver v1.17.0 - v1.17.2
• kube-apiserver v1.16.0 - v1.16.6
• kube-apiserver < v1.15.10

How do I mitigate this vulnerability?

Prior to upgrading, these vulnerabilities can be mitigated by:

• Preventing unauthenticated or unauthorized access to the affected components
• The apiserver and kubelet should auto restart in the event of an OOM error

Fixed Versions

Both vulnerabilities are patched in kubernetes versions

• v1.17.3
• v1.16.7
• v1.15.10

To upgrade, refer to the documentation: https://kubernetes.io/docs/tasks/administer-cluster/cluster-management/#upgrading-a-cluster

Additional Details

See the GitHub issues for more details:

CVE-2020-8551: https://github.com/kubernetes/kubernetes/issues/89377
CVE-2020-8552: https://github.com/kubernetes/kubernetes/issues/89378

Thank You,

Tim Allclair on behalf of the Kubernetes Product Security Committee