CVE-2020-8562

{"containers": {"cna": {"affected": [{"product": "Kubernetes", "vendor": "Kubernetes", "versions": [{"lessThan": "*", "status": "affected", "version": "0", "versionType": "semver"}]}], "credits": [{"lang": "en", "value": "Javier Provecho"}], "datePublic": "2021-05-04T00:00:00.000Z", "descriptions": [{"lang": "en", "value": "As mitigations to a report from 2019 and CVE-2020-8555, Kubernetes attempts to prevent proxied connections from accessing link-local or localhost networks when making user-driven connections to Services, Pods, Nodes, or StorageClass service providers. As part of this mitigation Kubernetes does a DNS name resolution check and validates that response IPs are not in the link-local (169.254.0.0/16) or localhost (127.0.0.0/8) range. Kubernetes then performs a second DNS resolution without validation for the actual connection. If a non-standard DNS server returns different non-cached responses, a user may be able to bypass the proxy IP restriction and access private networks on the control plane."}], "metrics": [{"cvssV3_1": {"attackComplexity": "HIGH", "attackVector": "NETWORK", "availabilityImpact": "NONE", "baseScore": 2.2, "baseSeverity": "LOW", "confidentialityImpact": "LOW", "integrityImpact": "NONE", "privilegesRequired": "HIGH", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:L/I:N/A:N", "version": "3.1"}}], "problemTypes": [{"descriptions": [{"cweId": "CWE-367", "description": "CWE-367 Time-of-check Time-of-use (TOCTOU) Race Condition", "lang": "en", "type": "CWE"}]}], "providerMetadata": {"orgId": "a6081bf6-c852-4425-ad4f-a67919267565", "shortName": "kubernetes", "dateUpdated": "2026-06-01T21:45:40.339Z"}, "references": [{"tags": ["x_refsource_MISC"], "url": "https://kubernetes.io/blog/2026/05/26/reconciling-unfixed-kubernetes-cves/"}, {"tags": ["x_refsource_MISC"], "url": "https://github.com/kubernetes/kubernetes/issues/101493"}, {"tags": ["x_refsource_MISC"], "url": "https://groups.google.com/g/kubernetes-security-announce/c/-MFX60_wdOY"}, {"tags": ["x_refsource_CONFIRM"], "url": "https://security.netapp.com/advisory/ntap-20220225-0002/"}], "source": {"defect": ["https://github.com/kubernetes/kubernetes/issues/101493"], "discovery": "EXTERNAL"}, "title": "Bypass of Kubernetes API Server proxy TOCTOU", "workarounds": [{"lang": "en", "value": "If this issue affects your clusters\u2019 control planes, you can use dnsmasq for name resolution and configure the min-cache-ttl and neg-ttl parameters to a low non-zero value to enforce cached replies for proxied connections"}], "x_generator": {"engine": "Vulnogram 0.0.9"}}, "adp": [{"providerMetadata": {"orgId": "af854a3a-2127-422b-91ae-364da2661108", "shortName": "CVE", "dateUpdated": "2024-08-04T10:03:46.172Z"}, "title": "CVE Program Container", "references": [{"tags": ["x_refsource_MISC", "x_transferred"], "url": "https://github.com/kubernetes/kubernetes/issues/101493"}, {"tags": ["x_refsource_MISC", "x_transferred"], "url": "https://groups.google.com/g/kubernetes-security-announce/c/-MFX60_wdOY"}, {"tags": ["x_refsource_CONFIRM", "x_transferred"], "url": "https://security.netapp.com/advisory/ntap-20220225-0002/"}]}]}, "cveMetadata": {"assignerOrgId": "a6081bf6-c852-4425-ad4f-a67919267565", "assignerShortName": "kubernetes", "cveId": "CVE-2020-8562", "datePublished": "2022-02-01T10:33:00.317Z", "dateReserved": "2020-02-03T00:00:00.000Z", "dateUpdated": "2026-06-01T21:45:40.339Z", "state": "PUBLISHED"}, "dataType": "CVE_RECORD", "dataVersion": "5.2"}

{}

{"affected": [{"affectedData": [{"product": "Kubernetes", "vendor": "Kubernetes", "versions": [{"lessThan": "*", "status": "affected", "version": "0", "versionType": "semver"}]}], "source": "jordan@liggitt.net"}], "configurations": [{"nodes": [{"cpeMatch": [{"criteria": "cpe:2.3:a:kubernetes:kubernetes:*:*:*:*:*:*:*:*", "matchCriteriaId": "7BE1AD99-F12A-4F6E-8EA5-578F32A1F15F", "versionEndIncluding": "1.18.18", "vulnerable": true}, {"criteria": "cpe:2.3:a:kubernetes:kubernetes:*:*:*:*:*:*:*:*", "matchCriteriaId": "34CCC198-AAA6-4DAE-94C4-B8CE55F621F7", "versionEndIncluding": "1.19.10", "versionStartIncluding": "1.19.0", "vulnerable": true}, {"criteria": "cpe:2.3:a:kubernetes:kubernetes:*:*:*:*:*:*:*:*", "matchCriteriaId": "6868B56F-DDBE-4CDA-9537-A0CAD3CDB1AB", "versionEndIncluding": "1.20.6", "versionStartIncluding": "1.20.0", "vulnerable": true}, {"criteria": "cpe:2.3:a:kubernetes:kubernetes:1.21.0:*:*:*:*:*:*:*", "matchCriteriaId": "1A3D8AFD-1FB4-4F98-8522-E57A15DD00BB", "vulnerable": true}], "negate": false, "operator": "OR"}]}], "cveTags": [], "descriptions": [{"lang": "en", "value": "As mitigations to a report from 2019 and CVE-2020-8555, Kubernetes attempts to prevent proxied connections from accessing link-local or localhost networks when making user-driven connections to Services, Pods, Nodes, or StorageClass service providers. As part of this mitigation Kubernetes does a DNS name resolution check and validates that response IPs are not in the link-local (169.254.0.0/16) or localhost (127.0.0.0/8) range. Kubernetes then performs a second DNS resolution without validation for the actual connection. If a non-standard DNS server returns different non-cached responses, a user may be able to bypass the proxy IP restriction and access private networks on the control plane."}, {"lang": "es", "value": "Como mitigaci\u00f3n a un informe de 2019 y CVE-2020-8555, Kubernetes intenta impedir que las conexiones proxy accedan a las redes link-local o localhost cuando son realizadas conexiones impulsadas por el usuario a los servicios, pods, nodos o proveedores de servicios StorageClass. Como parte de esta mitigaci\u00f3n, Kubernetes realiza una comprobaci\u00f3n de resoluci\u00f3n de nombres DNS y comprueba que las IPs de respuesta no est\u00e9n en el rango link-local (169.254.0.0/16) o localhost (127.0.0/8). A continuaci\u00f3n, Kubernetes lleva a cabo una segunda resoluci\u00f3n de DNS sin comprobar para la conexi\u00f3n real. Si un servidor DNS no est\u00e1ndar devuelve diferentes respuestas no almacenadas en cach\u00e9, un usuario puede ser capaz de omitir la restricci\u00f3n de la IP del proxy y acceder a redes privadas en el plano de control"}], "id": "CVE-2020-8562", "lastModified": "2026-06-17T03:26:33.373", "metrics": {"cvssMetricV2": [{"acInsufInfo": false, "baseSeverity": "LOW", "cvssData": {"accessComplexity": "MEDIUM", "accessVector": "NETWORK", "authentication": "SINGLE", "availabilityImpact": "NONE", "baseScore": 3.5, "confidentialityImpact": "PARTIAL", "integrityImpact": "NONE", "vectorString": "AV:N/AC:M/Au:S/C:P/I:N/A:N", "version": "2.0"}, "exploitabilityScore": 6.8, "impactScore": 2.9, "obtainAllPrivilege": false, "obtainOtherPrivilege": false, "obtainUserPrivilege": false, "source": "nvd@nist.gov", "type": "Primary", "userInteractionRequired": false}], "cvssMetricV31": [{"cvssData": {"attackComplexity": "HIGH", "attackVector": "NETWORK", "availabilityImpact": "NONE", "baseScore": 2.2, "baseSeverity": "LOW", "confidentialityImpact": "LOW", "integrityImpact": "NONE", "privilegesRequired": "HIGH", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:L/I:N/A:N", "version": "3.1"}, "exploitabilityScore": 0.7, "impactScore": 1.4, "source": "jordan@liggitt.net", "type": "Secondary"}, {"cvssData": {"attackComplexity": "HIGH", "attackVector": "NETWORK", "availabilityImpact": "NONE", "baseScore": 3.1, "baseSeverity": "LOW", "confidentialityImpact": "LOW", "integrityImpact": "NONE", "privilegesRequired": "LOW", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N", "version": "3.1"}, "exploitabilityScore": 1.6, "impactScore": 1.4, "source": "nvd@nist.gov", "type": "Primary"}]}, "published": "2022-02-01T11:15:10.903", "references": [{"source": "jordan@liggitt.net", "tags": ["Issue Tracking", "Mitigation", "Third Party Advisory"], "url": "https://github.com/kubernetes/kubernetes/issues/101493"}, {"source": "jordan@liggitt.net", "tags": ["Mailing List", "Third Party Advisory"], "url": "https://groups.google.com/g/kubernetes-security-announce/c/-MFX60_wdOY"}, {"source": "jordan@liggitt.net", "url": "https://kubernetes.io/blog/2026/05/26/reconciling-unfixed-kubernetes-cves/"}, {"source": "jordan@liggitt.net", "tags": ["Third Party Advisory"], "url": "https://security.netapp.com/advisory/ntap-20220225-0002/"}, {"source": "af854a3a-2127-422b-91ae-364da2661108", "tags": ["Issue Tracking", "Mitigation", "Third Party Advisory"], "url": "https://github.com/kubernetes/kubernetes/issues/101493"}, {"source": "af854a3a-2127-422b-91ae-364da2661108", "tags": ["Mailing List", "Third Party Advisory"], "url": "https://groups.google.com/g/kubernetes-security-announce/c/-MFX60_wdOY"}, {"source": "af854a3a-2127-422b-91ae-364da2661108", "tags": ["Third Party Advisory"], "url": "https://security.netapp.com/advisory/ntap-20220225-0002/"}], "sourceIdentifier": "jordan@liggitt.net", "vulnStatus": "Modified", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-367"}], "source": "jordan@liggitt.net", "type": "Secondary"}, {"description": [{"lang": "en", "value": "CWE-367"}], "source": "nvd@nist.gov", "type": "Primary"}]}

{"acknowledgement": "Red Hat would like to thank the Kubernetes Product Security Committee for reporting this issue. Upstream acknowledges Javier Provecho (Telefonica) as the original reporter.", "bugzilla": {"description": "kubernetes: Bypass of Kubernetes API Server proxy TOCTOU", "id": "1954914", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=1954914"}, "csaw": false, "cvss3": {"cvss3_base_score": "2.2", "cvss3_scoring_vector": "CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:L/I:N/A:N", "status": "draft"}, "cwe": "CWE-367", "details": ["As mitigations to a report from 2019 and CVE-2020-8555, Kubernetes attempts to prevent proxied connections from accessing link-local or localhost networks when making user-driven connections to Services, Pods, Nodes, or StorageClass service providers. As part of this mitigation Kubernetes does a DNS name resolution check and validates that response IPs are not in the link-local (169.254.0.0/16) or localhost (127.0.0.0/8) range. Kubernetes then performs a second DNS resolution without validation for the actual connection. If a non-standard DNS server returns different non-cached responses, a user may be able to bypass the proxy IP restriction and access private networks on the control plane.", "A security issue was discovered in Kubernetes where an authorized user may be able to access private networks on the Kubernetes control plane components. Kubernetes clusters are only affected if an untrusted user can create or modify Node objects and proxy to them, or an untrusted user can create or modify StorageClass objects and access KubeControllerManager logs."], "name": "CVE-2020-8562", "package_state": [{"cpe": "cpe:/a:redhat:openshift:3.11", "fix_state": "Fix deferred", "package_name": "atomic-openshift", "product_name": "Red Hat OpenShift Container Platform 3.11"}, {"cpe": "cpe:/a:redhat:openshift:4", "fix_state": "Fix deferred", "package_name": "openshift", "product_name": "Red Hat OpenShift Container Platform 4"}], "public_date": "2021-05-04T00:00:00Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2020-8562\nhttps://nvd.nist.gov/vuln/detail/CVE-2020-8562\nhttps://groups.google.com/g/kubernetes-security-announce/c/-MFX60_wdOY"], "threat_severity": "Low"}

{}