Privilege escalation in Kubertenes

1) Privilege escalation

EUVDB-ID: #VU16224

Risk: High

CVSSv4.0: 8.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:P/U:Amber]

CVE-ID: CVE-2018-1002105

CWE-ID: CWE-264 - Permissions, Privileges, and Access Controls

Exploit availability: Yes

Description

The vulnerability allows a remote attacker to gain elevated privileges on the target system.

The weakness exists due to an error when handling proxy requests. With a specially crafted request, users that are authorized to establish a connection through the Kubernetes API server to a backend server can then send arbitrary requests over the same connection directly to that backend, authenticated with the Kubernetes API server’s TLS credentials used to establish the backend connection.

Mitigation

The vulnerability has been fixed in the versions 1.10.11, 1.11.5, 1.12.3, 1.13.0-rc.1.

Vulnerable software versions

Kubernetes: 1.3.0 - 1.12.2

CPE2.3

• cpe:2.3:a:kubernetes:kubernetes:1.3.10:*:*:*:*:*:*:*
• cpe:2.3:a:kubernetes:kubernetes:1.4.12:*:*:*:*:*:*:*
• cpe:2.3:a:kubernetes:kubernetes:1.5.8:*:*:*:*:*:*:*
• cpe:2.3:a:kubernetes:kubernetes:1.6.13:*:*:*:*:*:*:*
• cpe:2.3:a:kubernetes:kubernetes:1.7.16:*:*:*:*:*:*:*
• cpe:2.3:a:kubernetes:kubernetes:1.8.15:*:*:*:*:*:*:*
• cpe:2.3:a:kubernetes:kubernetes:1.9.11:*:*:*:*:*:*:*
• cpe:2.3:a:kubernetes:kubernetes:1.12.2:*:*:*:*:*:*:*

External links

https://github.com/kubernetes/kubernetes/issues/71411

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. However, proof of concept for this vulnerability is available.