#VU85950 Path traversal in Java client for Kubernetes & OpenShift - CVE-2021-20218

Vulnerability identifier: #VU85950

Vulnerability risk: Medium

CVSSv4.0: 4.9 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2021-20218

CWE-ID: CWE-22

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Java client for Kubernetes & OpenShift
Client/Desktop applications / Software for system administration

Vendor: fabric8io

Description

The vulnerability allows a remote attacker to perform directory traversal attacks.

The vulnerability exists due to malicious pod/container can cause applications using the fabric8 kubernetes-client `copy` command to extract files outside the working path. A remote attacker can send a specially crafted HTTP request and read arbitrary files on the system.

Mitigation
Install update from vendor's website.

Vulnerable software versions

Java client for Kubernetes & OpenShift: before 4.7.2, 4.11.2, 4.13.2, 5.0.2, 4.7.2, 4.7.2, 4.7.2

---

External links
https://bugzilla.redhat.com/show_bug.cgi?id=1923405
https://github.com/fabric8io/kubernetes-client/issues/2715

---

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.