Input validation error in Kubernetes



Published: 2021-09-01 | Updated: 2021-09-12
Risk Medium
Patch available YES
Number of vulnerabilities 1
CVE-ID CVE-2021-25735
CWE-ID CWE-20
Exploitation vector Network
Public exploit Public exploit code for vulnerability #1 is available.
Vulnerable software
Subscribe 		Kubernetes
Server applications / Frameworks for developing and running applications

Vendor Kubernetes

Security Bulletin

This security bulletin contains one medium risk vulnerability.

1) Input validation error

EUVDB-ID: #VU56245

Risk: Medium

CVSSv3.1: 4.7 [CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N/E:U/RL:O/RC:C]

CVE-ID: CVE-2021-25735

CWE-ID: CWE-20 - Improper input validation

Exploit availability: Yes

Description

The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to insufficient validation of user-supplied input in kube-apiserver that could allow Node updates to bypass a Validating Admission Webhook. An authenticated user could exploit this by modifying Node properties to values that should have been prevented by registered admission webhooks.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Kubernetes: 1.18.0 - 1.20.5

External links

http://github.com/kubernetes/kubernetes/issues/100096
http://bugzilla.redhat.com/show_bug.cgi?id=1937562


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.



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