Vulnerability in Kubelet (CVE-2020-8558)
Summary
Vulnerability in Kubelet (CVE-2020-8558). Successful exploitation can lead to full system takeover.
Original description
The description as published by the source.
A security issue was discovered in the Kubelet and kube-proxy components of Kubernetes which allows adjacent hosts to reach TCP and UDP services bound to 127.0.0.1 running on the node or in the node's network namespace. For example, if a cluster administrator runs a TCP service on a node that listens on 127.0.0.1:1234, because of this bug, that service would be potentially reachable by other hosts on the same LAN as the node, or by containers running on the same node as the service. If the example service on port 1234 required no additional authentication (because it assumed that only other localhost processes could reach it), then it could be vulnerable to attacks that make use of this bug.
Source: OSV.dev (Open Source Vulnerabilities) NVD GitHub Advisory OSV
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2020-8558 has been found in Kubelet.
Successful exploitation can lead to full system takeover.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "Kubelet CVE-2020-8558" on the vendor's site.
CVE-2020-8558 (Kubelet)
Attack vector: adjacent-network / unauthenticated / no user interaction
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
A vulnerability (unclassified) exists in Kubelet.
Check the vendor advisory for the affected versions of Kubelet.
Severity: ?. Successful exploitation can lead to full system takeover.
Update to the patched release per vendor advisory.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'Kubelet' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1Identify exposure identify
grep -r 'Kubelet' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
Kubeletを grep し、稼働しているサービス・バージョンを把握する。 -
2Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
Affected packages
Fix status by distribution
Fixed packages published by each distribution for this CVE
- Debian DEBIAN-CVE-2020-8558 kubernetes Fixed in: 1.18.5-1
References
- advisory security.netapp.com
- advisory nvd.nist.gov
- package github.com
- web github.com
- web groups.google.com
- web github.com
- web bugzilla.redhat.com
- web cve.mitre.org
- web github.com
- web groups.google.com
- web labs.bishopfox.com
- web security.netapp.com
- web openwall.com