Information disclosure in Kubernetes CSI sidecar containers for external-provisioner

1) Input validation error

EUVDB-ID: #VU23548

Risk: Low

CVSSv3.1: 2.9 [CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N/E:U/RL:O/RC:C]

CVE-ID: CVE-2019-11255

CWE-ID: CWE-20 - Improper input validation

Exploit availability: No

Description

The vulnerability allows a remote attacker to gain access to sensitive information.

The vulnerability exists due to insufficient validation of user-supplied input in Kubernetes CSI sidecar containers for external-provisioner (versions prior to 0.4.3 and 1.0.2, in version 1.1,  and versions prior to 1.2.2 and 1.3.1), external-snapshotter (versions prior to 0.4.2 and 1.0.2, in version 1.1, versions prior to 1.2.2), and external-resizer (versions 0.1,  and 0.2) . A local user can gain unauthorized PersistentVolume data access or volume mutation during snapshot, restore from snapshot, cloning and resizing operations.

Mitigation

Install update from vendor's website.

Vulnerable software versions

Kubernetes: 1.12.0 - 1.16.3

External links

http://access.redhat.com/errata/RHSA-2019:4099
http://github.com/kubernetes/kubernetes/issues/85233
http://groups.google.com/forum/#!topic/kubernetes-security-announce/aXiYN0q4uIw

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.