Denial of service in Kubernetes API server

1) Resource exhaustion

EUVDB-ID: #VU22824

Risk: Medium

CVSSv3.1: 6.5 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2019-11253

CWE-ID: CWE-400 - Resource exhaustion

Exploit availability: No

Description

The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to improper input validation when processing YAML or JSON data in Kubernetes API server. A remote attacker can pass a malicious file to the API server and consume excessive memory and CPU resources, leading to a denial of service (DoS) attack.

Note, this vulnerability can be exploited by a remote non-authenticated attacker in Kubernetes versions prior to 1.14.0 due to default RBAC policy.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Kubernetes: 1.0.0 - 1.16.1

External links

http://access.redhat.com/errata/RHSA-2019:3239
http://github.com/kubernetes/kubernetes/issues/83253
http://groups.google.com/forum/#!topic/kubernetes-security-announce/jk8polzSUxs

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.