Security restrictions bypass in Kubernetes

1) Security restrictions bypass

EUVDB-ID: #VU56902

Risk: Medium

CVSSv4.0: 7.4 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:P/U:Green]

CVE-ID: CVE-2021-25741

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

Exploit availability: Yes

Description

The vulnerability allows a remote user to bypass implemented security restrictions.

The vulnerability exists due to application does not properly impose security restrictions by allowing hostPath-like access without use of the hostPath feature. A remote user can create a container with subpath volume mounts to access files and directories outside of the volume, including on the host filesystem.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Kubernetes: - - 1.22.1

CPE2.3

• cpe:2.3:a:kubernetes:kubernetes:0.2:*:*:*:*:*:*:*
• cpe:2.3:a:kubernetes:kubernetes:0.3:*:*:*:*:*:*:*
• cpe:2.3:a:kubernetes:kubernetes:0.4.4:*:*:*:*:*:*:*
• cpe:2.3:a:kubernetes:kubernetes:0.5.6:*:*:*:*:*:*:*
• cpe:2.3:a:kubernetes:kubernetes:0.6.2:*:*:*:*:*:*:*
• cpe:2.3:a:kubernetes:kubernetes:0.7.4:*:*:*:*:*:*:*
• cpe:2.3:a:kubernetes:kubernetes:0.8.4:*:*:*:*:*:*:*
• cpe:2.3:a:kubernetes:kubernetes:0.9.3:*:*:*:*:*:*:*
• cpe:2.3:a:kubernetes:kubernetes:0.10.1:*:*:*:*:*:*:*
• cpe:2.3:a:kubernetes:kubernetes:0.11.0:*:*:*:*:*:*:*

External links

https://groups.google.com/g/kubernetes-security-announce/c/nyfdhK24H7s
https://github.com/kubernetes/kubernetes/issues/104980

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote authenticated user 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.