#VU94655 Time-of-check Time-of-use (TOCTOU) Race Condition in Kubernetes - CVE-2020-8562

Vulnerability identifier: #VU94655

Vulnerability risk: Low

CVSSv4.0: 0.5 [CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2020-8562

CWE-ID: CWE-367

Exploitation vector: Network

Exploit availability: No

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

Vendor: Kubernetes

Description

The vulnerability allows a remote privileged user to gain access to potentially sensitive information.

The vulnerability exists due to a time-of-check time-of-use (TOCTOU) race condition flaw in the API Server proxy. A remote privileged user can send a specially-crafted request and exploit this vulnerability to gain access to private networks on the Kubernetes control plane components.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Kubernetes: 1.19.0 - 1.19.10, 1.20.0 - 1.20.6

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External links
https://groups.google.com/g/kubernetes-security-announce/c/-MFX60_wdOY
https://github.com/kubernetes/kubernetes/issues/101493
https://security.netapp.com/advisory/ntap-20220225-0002/

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote authenticated privileged user via the Internet.

Is there known malware, which exploits this vulnerability?

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