#VU22431 UNIX symbolic link following in Kubernetes - CVE-2019-11251

Vulnerability identifier: #VU22431

Vulnerability risk: Low

CVSSv4.0: 1.1 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2019-11251

CWE-ID: CWE-61

Exploitation vector: Local

Exploit availability: No

Vulnerable software:
Kubernetes
Server applications / Frameworks for developing and running applications

Vendor: Kubernetes

Description

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

The vulnerability exists due to a symlink following issue in kubectl cp. A local user can create two symbolic links and overwrite files on the system with privileges of the application.

Successful exploitation of this vulnerability may result in privilege escalation.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Kubernetes: 1.13.0 rc1 - 1.15.3

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External links
https://github.com/kubernetes/kubernetes/pull/82143
https://github.com/kubernetes/kubernetes/pull/82143
https://github.com/kubernetes/kubernetes/pull/82384
https://github.com/kubernetes/kubernetes/pull/82502
https://github.com/kubernetes/kubernetes/pull/82503

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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.