CVE-2020-8562

NameCVE-2020-8562
DescriptionAs 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.
SourceCVE (at NVD; CERT, LWN, oss-sec, fulldisc, bugtraq, EDB, Metasploit, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, Mageia, GitHub advisories/code/issues, web search, more)
Debian Bugs990793

Vulnerable and fixed packages

The table below lists information on source packages.

Source PackageReleaseVersionStatus
kubernetes (PTS)bullseye1.20.5+really1.20.2-1fixed
bookworm, sid1.20.5+really1.20.2-1.1vulnerable

The information below is based on the following data on fixed versions.

PackageTypeReleaseFixed VersionUrgencyOriginDebian Bugs
kubernetessourcebullseye(not affected)
kubernetessource(unstable)(unfixed)990793

Notes

[bullseye] - kubernetes <not-affected> (Kubernetes in Bullseye only ships the client)
https://www.openwall.com/lists/oss-security/2021/05/04/8
Server components no longer built since 1.20.5+really1.20.2-1

Search for package or bug name: Reporting problems