CVE-2020-8562
WITHDRAWN: Potential proxy IP restriction bypass in Kubernetes in k8s.io/kubernetes
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.
How to fix CVE-2020-8562
To remediate CVE-2020-8562, upgrade the affected package to a fixed version below.
- —upgrade to 1.20.5+really1.20.2-1 or later
- —no fix listed
- —no fix listed
Is CVE-2020-8562 being exploited?
Low — EPSS is 0.1%, meaning exploitation activity has not been observed at scale.
Affected packages (3)
- from 0, < 1.20.5+really1.20.2-1
- >= 1.21.0, <= 1.21.1
- from 0
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 3.1 | LOW3.1 | CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N |