MitM attack in Kubernetes



Published: 2021-06-23
Risk Medium
Patch available YES
Number of vulnerabilities 1
CVE-ID CVE-2021-25736
CWE-ID CWE-693
Exploitation vector Network
Public exploit N/A
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) Protection Mechanism Failure

EUVDB-ID: #VU54339

Risk: Medium

CVSSv3.1: 5.6 [CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N/E:U/RL:O/RC:C]

CVE-ID: CVE-2021-25736

CWE-ID: CWE-693 - Protection Mechanism Failure

Exploit availability: No

Description

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

The vulnerability exists due to insufficient implementation of security measures in the Windows kube-proxy component. In a cloud environment that does not set the “.status.loadBalancer.ingress.ip” field in the LoadBalancer service status configuration (for example in AWS) the packets can be misrouted and reach an unintended destination. An attacker can bypass implemented security restrictions and perform MitM attack.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Kubernetes: 1.18.0 - 1.20.5

External links

http://access.redhat.com/errata/RHSA-2021:2130


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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