CVE-2020-8562
Bypass of Kubernetes API Server proxy TOCTOU
LOW 3.1EPSS 1.1%
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.
- Affected
- Kubernetes
- CVSS v3.1 NVD
- 3.1 LOW
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N - CVSS v3.1 LIGGITT
- 2.2 LOW
CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:L/I:N/A:N - CVSS v2.0 NVD
- 3.5 LOW
AV:N/AC:M/Au:S/C:P/I:N/A:N - EPSS
- 1.08% chance of exploitation in the next 30 days, 63rd percentile
- Published
- 2022-02-01
- Updated
- 2026-06-01