Resource exhaustion in Kubernetes
CVE-2020-8557
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.
Vulnerability class: DoS (Denial of Service)
EPSS: 0.005 (40.0th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 5.5 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.
Affected products
- Kubernetes — versions 1.15, 1.14, 1.13
Weakness classification (CWE)
Public proof-of-concept exploits
- ARPSyndicate/cvemon
- Kiranp295/CKS
- Live-Hack-CVE/CVE-2020-8557
- Metarget/metarget
- SebastianUA/Certified-Kubernetes-Security-Specialist
- adavarski/HomeLab-Proxmox-k8s-DevSecOps-playground
- adavarski/HomeLab-k8s-DevSecOps-playground
- ashrafulislamcs/-Certified-Kubernetes-Security-Specialist
- neargle/my-re0-k8s-security
- neargle/re0-kubernetes-sec-archive
References
- jordan@liggitt.net (x_refsource_CONFIRM, Patch, Third Party Advisory, Issue Tracking)
- jordan@liggitt.net (mailing-list, x_refsource_MLIST, Mailing List, Third Party Advisory)
- jordan@liggitt.net (x_refsource_CONFIRM, Third Party Advisory)
Frequently asked questions
- What is CVE-2020-8557?
- CVE-2020-8557 is a medium-severity vulnerability in Kubernetes, classified under Uncontrolled Resource Consumption. CVSS score: 5.5/10. Published 2020-07-23.
- How severe is CVE-2020-8557?
- Medium severity. CVSS v3 base score is 5.5 out of 10.
- Is CVE-2020-8557 known to be exploited?
- 12 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.