SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityModified

CVE-2020-8562

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.

LOW 3.1EPSS 1.08%

Does this matter?

Lower severity and a low EPSS score (1.08%). Track it; it rarely justifies an emergency change on its own.

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.

CVSS 3.1
3.1 LOWCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N
EPSS
1.08% probability · 63th percentile
CISA KEV
Not listed
Weakness
CWE-367
Affected
kubernetes/kubernetes
Source
jordan@liggitt.net

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.