{"id":"UBUNTU-CVE-2020-8562","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private networks on the control plane.","modified":"2025-07-14T07:00:33.345952Z","published":"2022-02-01T11:15:00Z","withdrawn":"2025-08-28T16:59:42Z","upstream":["CVE-2020-8562"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2020-8562"},{"type":"REPORT","url":"https://www.openwall.com/lists/oss-security/2021/05/04/8"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2020-8562"}],"affected":[{"package":{"name":"kubernetes","ecosystem":"Ubuntu:Pro:20.04:LTS","purl":"pkg:deb/ubuntu/kubernetes@1.0?arch=source&distro=esm-apps/focal"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.0"],"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2020/UBUNTU-CVE-2020-8562.json"}},{"package":{"name":"kubernetes","ecosystem":"Ubuntu:22.04:LTS","purl":"pkg:deb/ubuntu/kubernetes@1.0?arch=source&distro=jammy"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.0"],"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2020/UBUNTU-CVE-2020-8562.json"}},{"package":{"name":"kubernetes","ecosystem":"Ubuntu:24.04:LTS","purl":"pkg:deb/ubuntu/kubernetes@1.0?arch=source&distro=noble"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.0"],"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2020/UBUNTU-CVE-2020-8562.json"}}],"schema_version":"1.7.3","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:L/I:N/A:N"},{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N"},{"type":"Ubuntu","score":"low"}]}