VULNERABILITY INTELLIGENCE
CVE-2020-8562
CVSS score2.2 LOW
EPSS probability1.19%
CISA KEVNot currently listed
Published2022-02-01
Last modified2026-06-17
CVSS vectorCVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:L/I:N/A:N
Description
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.
Weakness classification
- CWE-367: Time-of-check Time-of-use (TOCTOU) Race Condition
Primary references
- jordan@liggitt.net — Issue Tracking, Mitigation, Third Party Advisory
- jordan@liggitt.net — Mailing List, Third Party Advisory
- jordan@liggitt.net
- jordan@liggitt.net — Third Party Advisory
- af854a3a-2127-422b-91ae-364da2661108 — Issue Tracking, Mitigation, Third Party Advisory
- af854a3a-2127-422b-91ae-364da2661108 — Mailing List, Third Party Advisory
- af854a3a-2127-422b-91ae-364da2661108 — Third Party Advisory