CVE-2020-8557

Kubernetes node disk Denial of Service by writing to container /etc/hosts

Description

The Kubernetes kubelet component in versions 1.1-1.16.12, 1.17.0-1.17.8 and 1.18.0-1.18.5 do not account for disk usage by a pod which writes to its own /etc/hosts file. The /etc/hosts file mounted in a pod by kubelet is not included by the kubelet eviction manager when calculating ephemeral storage usage by a pod. If a pod writes a large amount of data to the /etc/hosts file, it could fill the storage space of the node and cause the node to fail.

Category

5.5
CVSS
Severity: Medium
CVSS 3.1 •
CVSS 2.0 •
EPSS 0.29%
Third-Party Advisory github.com Third-Party Advisory google.com Third-Party Advisory netapp.com
Affected: Kubernetes Kubernetes
Published at:
Updated at:

References

Link Tags
https://github.com/kubernetes/kubernetes/issues/93032 patch third party advisory issue tracking
https://groups.google.com/g/kubernetes-security-announce/c/cB_JUsYEKyY/m/vVSO61AhBwAJ third party advisory mailing list
https://security.netapp.com/advisory/ntap-20200821-0002/ third party advisory

Frequently Asked Questions

What is the severity of CVE-2020-8557?
CVE-2020-8557 has been scored as a medium severity vulnerability.
How to fix CVE-2020-8557?
To fix CVE-2020-8557, make sure you are using an up-to-date version of the affected component(s) by checking the vendor release notes. As for now, there are no other specific guidelines available.
Is CVE-2020-8557 being actively exploited in the wild?
As for now, there are no information to confirm that CVE-2020-8557 is being actively exploited. According to its EPSS score, there is a ~0% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
What software or system is affected by CVE-2020-8557?
CVE-2020-8557 affects Kubernetes Kubernetes.
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