CVE-2021-25737

low
Published 2021-09-07 · Modified 2026-03-03
CVSS v3
CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N
CVSS v2
VIR risk
2.5

Description

A security issue was discovered in Kubernetes where a user may be able to redirect pod traffic to private networks on a Node. Kubernetes already prevents creation of Endpoint IPs in the localhost or link-local range, but the same validation was not performed on EndpointSlice IPs.

Predictions

Exploit likelihood
30%
Patch ETA

Heuristic predictions, AS-IS, for prioritization only.

Mitigations

vendor Authored 2026-05-27

Vendor advisory: debian — https://security-tracker.debian.org/tracker/CVE-2021-25737

vendor Authored 2026-05-27

Vendor advisory: suse — https://www.suse.com/security/cve/CVE-2021-25737.html

vendor Authored 2026-05-27

Vendor advisory: arch — https://security.archlinux.org/ASA-202106-29

OS impact

OSVersionStatusFixed in
arch archfixed1.21.1-1
suse slesaffected
debian debianbookwormfixed1.20.5+really1.20.2-1
debian debianbullseyefixed1.20.5+really1.20.2-1
debian debianforkyfixed1.20.5+really1.20.2-1
debian debiansidfixed1.20.5+really1.20.2-1
debian debiantrixiefixed1.20.5+really1.20.2-1

Package impact

EcosystemPackageVulnerableFixed
golang Gok8s.io/kubernetes>=1.16.0,<1.18.191.18.19
golang Gok8s.io/kubernetes>=1.19.0,<1.19.111.19.11
golang Gok8s.io/kubernetes>=1.20.0,<1.20.71.20.7
golang Gok8s.io/kubernetes>=1.21.0,<1.21.11.21.1

References

Verify integrity in audit chain (admin only). AS-IS.