Kubernetes node disk Denial of Service by writing to container /etc/hosts
Priority LOW 25CWE-400Published · Updated
Key facts
- Attack vector
- Local
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Denial of service
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA, GitHub and Red Hat. Impact type from CWE-400.
Summary
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.
Why it matters now
EPSS 0.00434 37th percentileScored 2026-11-07
Fix Fixed Kubernetes (Kubernetes): 1.18.6, 1.17.9, 1.16.13k8s.io/kubernetes/pkg/kubelet (Go): 1.16.13, 1.17.9, 1.18.6Red Hat: 7 advisories
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Kubernetes | Kubernetes | 1.15; 1.14; 1.13; 1.12; 1.11; 1.10; 1.9; 1.8; 1.7; 1.6; 1.5; 1.4; 1.3; 1.2; 1.1; 1.18 to before 1.18.6; 1.17 to before 1.17.9; 1.16 to before 1.16.13 | 1.18.6, 1.17.9, 1.16.13 | Patch available | CNA |
| — | k8s.io/kubernetes/pkg/kubelet (Go) | 1.1.0 to before 1.16.13 | 1.16.13 | Patch available | GHSA-55qj-gj3x-jq9r |
| — | k8s.io/kubernetes/pkg/kubelet (Go) | 1.17.0 to before 1.17.9 | 1.17.9 | Patch available | GHSA-55qj-gj3x-jq9r |
| — | k8s.io/kubernetes/pkg/kubelet (Go) | 1.18.0 to before 1.18.6 | 1.18.6 | Patch available | GHSA-55qj-gj3x-jq9r |
- Kubernetes VendorKubernetes Affected 1.15; 1.14; 1.13; 1.12; 1.11; 1.10; 1.9; 1.8; 1.7; 1.6; 1.5; 1.4; 1.3; 1.2; 1.1; 1.18 to before 1.18.6; 1.17 to before 1.17.9; 1.16 to before 1.16.13 Fixed in 1.18.6, 1.17.9, 1.16.13 Patch available CNA
- k8s.io/kubernetes/pkg/kubelet (Go) Vendor— Affected 1.1.0 to before 1.16.13 Fixed in 1.16.13 Patch available GHSA-55qj-gj3x-jq9r
- k8s.io/kubernetes/pkg/kubelet (Go) Vendor— Affected 1.17.0 to before 1.17.9 Fixed in 1.17.9 Patch available GHSA-55qj-gj3x-jq9r
- k8s.io/kubernetes/pkg/kubelet (Go) Vendor— Affected 1.18.0 to before 1.18.6 Fixed in 1.18.6 Patch available GHSA-55qj-gj3x-jq9r
CPE configurations NVD · 1
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:kubernetes:kubernetes:*:*:*:*:*:*:*:* | before 1.16.13; 1.17.0 to before 1.17.9; 1.18.0 to before 1.18.6 | Vulnerable | Kubernetes |
- cpe:2.3:a:kubernetes:kubernetes:*:*:*:*:*:*:*:* Versions before 1.16.13; 1.17.0 to before 1.17.9; 1.18.0 to before 1.18.6 Vulnerable ·Kubernetes
Remediation
- Fix · CNA Kubernetes (Kubernetes) Fixed in 1.18.6, 1.17.9, 1.16.13
- Fix · GHSA-55qj-gj3x-jq9r k8s.io/kubernetes/pkg/kubelet (Go) Fixed in 1.16.13 Advisory →
- Fix · GHSA-55qj-gj3x-jq9r k8s.io/kubernetes/pkg/kubelet (Go) Fixed in 1.17.9 Advisory →
- Fix · GHSA-55qj-gj3x-jq9r k8s.io/kubernetes/pkg/kubelet (Go) Fixed in 1.18.6 Advisory →
Red Hat 7 advisories
- RHSA-2021:3915 Released 2021-10-28 · Red Hat rating ModerateOpenShift Container Platform 3.11.542 security update
- Red Hat OpenShift Container Platform 3.11 atomic-openshift-3.11.542-1.git.0.f2fd300.el7, atomic-openshift-clients-3.11.542-1.git.0.f2fd300.el7, atomic-openshift-clients-redistributable-3.11.542-1.git.0.f2fd300.el7 +10
- RHSA-2020:3809 Released 2020-09-23 · Red Hat rating ModerateOpenShift Container Platform 4.3.38 container image security update
- Red Hat OpenShift Container Platform 4.3 openshift4/ose-hyperkube, openshift4/ose-sriov-dp-admission-controller
- RHSA-2020:3808 Released 2020-09-23 · Red Hat rating ImportantOpenShift Container Platform 4.3.38 jenkins and openshift security update
- Red Hat OpenShift Container Platform 4.3 jenkins-2.235.5.1600415514-1.el7, openshift-4.3.37-202009120213.p0.git.0.dffefe4.el8, openshift-hyperkube-4.3.37-202009120213.p0.git.0.dffefe4.el8
Show 4 more Red Hat advisories
- RHSA-2020:3580 Released 2020-09-01 · Red Hat rating ModerateOpenShift Container Platform 4.4.19 openshift-enterprise-hyperkube-container security update
- Red Hat OpenShift Container Platform 4.4 openshift4/ose-hyperkube
- RHSA-2020:3579 Released 2020-09-01 · Red Hat rating ModerateOpenShift Container Platform 4.4.19 openshift security update
- Red Hat OpenShift Container Platform 4.4 openshift-4.4.0-202008250319.p0.git.0.d653415.el7, openshift-4.4.0-202008250319.p0.git.0.d653415.el8, openshift-hyperkube-4.4.0-202008250319.p0.git.0.d653415.el7 +1
- RHSA-2020:3520 Released 2020-08-24 · Red Hat rating ModerateOpenShift Container Platform 4.5.7 openshift-enterprise-hyperkube-container security update
- Red Hat OpenShift Container Platform 4.5 openshift4/ose-hyperkube
- RHSA-2020:3519 Released 2020-08-24 · Red Hat rating ImportantOpenShift Container Platform 4.5.7 jenkins and openshift packages security update
- Red Hat OpenShift Container Platform 4.5 jenkins-2.235.2.1597312414-1.el7, openshift-4.5.0-202008130146.p0.git.0.aaf1d57.el7, openshift-4.5.0-202008130146.p0.git.0.aaf1d57.el8 +2
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat OpenShift Container Platform 3.11 | Fixed | RHSA-2021:3915 |
| Red Hat OpenShift Container Platform 4.3 | Fixed | RHSA-2020:3808, RHSA-2020:3809 |
| Red Hat OpenShift Container Platform 4.4 | Fixed | RHSA-2020:3579, RHSA-2020:3580 |
| Red Hat OpenShift Container Platform 4.5 | Fixed | RHSA-2020:3519, RHSA-2020:3520 |
| Red Hat OpenShift Container Platform 4.6 | Fixed | — |
Not affected: 3 products
- Red Hat OpenShift Container Platform 3.11
- Red Hat OpenShift Container Platform 4.3
- Red Hat OpenShift Container Platform 4.5
Timeline
- 2026-10-02 Threatist record created from CVE-2020-8557
- 2026-10-03 Alias added: GHSA-55qj-gj3x-jq9r
- 2026-10-30 Fix available: Red Hat OpenShift Container Platform 4.6 · Red Hat
References
Advisory 4
Other 7
- https://github.com/kubernetes/kubernetes/pull/92921
- https://github.com/kubernetes/kubernetes/commit/530f199b6e07cdaab32361e39709ac45f3fdc446
- https://github.com/kubernetes/kubernetes/commit/68750fefd3df76b7b008ef7b18e8acd18d5c2f2e
- https://github.com/kubernetes/kubernetes/commit/7fd849cffa2f93061fbcb0a6ae4efd0539b1e981
- https://github.com/kubernetes/kubernetes
- https://pkg.go.dev/vuln/GO-2024-2753
- https://security.netapp.com/advisory/ntap-20200821-0002
More Kubernetes vulnerabilities
- TI-2018-16130 Improper privilege management in Kubernetes CVSS 3.0CRITICAL 9.8
- TI-2019-08418 Kubernetes kubelet exposes /debug/pprof info on healthz port CVSS 3.1HIGH 8.2
- TI-2023-05086 Kubernetes - Windows nodes - Insufficient input sanitization in in-tree storage plugin leads to privilege escalation CVSS 3.1HIGH 8.8
- TI-2023-03433 Kubernetes - Windows nodes - Insufficient input sanitization leads to privilege escalation CVSS 3.1HIGH 8.8
- TI-2023-02285 Bypass of seccomp profile enforcement CVSS 3.1MEDIUM 5.5
- TI-2017-14755 Link following in Kubernetes CVSS 3.0CRITICAL 9.6
Sources
- CVE-2020-8557 · CVE Program
- CVE-2020-8557 · NVD
- FIRST EPSS
- GHSA-55qj-gj3x-jq9r · GitHub Advisory Database · CC BY 4.0
- CVE-2020-8557 · Red Hat security data · CC BY 4.0
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