Insecure default permissions to cache directory in Kubernetes

1) Insecure default permissions

EUVDB-ID: #VU22937

Risk: Low

CVSSv3.1: 3.9 [CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N/E:U/RL:O/RC:C]

CVE-ID: CVE-2019-11244

CWE-ID: CWE-276 - Incorrect Default Permissions

Exploit availability: No

Description

The vulnerability allows a local user to escalate privileges on the system.

The vulnerability exists due to insecure default permissions for cache files directory, specified by "-cache-dir" option . A local user in a non-default Kubernetes configuration gain gain read/write access to cache files and gain access to sensitive information or disrupt kubectl invocation.

Mitigation

Install update from vendor's website.

Vulnerable software versions

Kubernetes: 1.8.0 - 1.14.9

External links

http://github.com/kubernetes/kubernetes/issues/76676
http://github.com/kubernetes/kubernetes/issues/80581
http://github.com/kubernetes/kubernetes/pull/77874/commits/f228ae3364729caed59087e23c42868454bc3ff4

Q & A

Can this vulnerability be exploited remotely?

No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.

Is there known malware, which exploits this vulnerability?

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