CVE-2021-25737

low

Published 2021-09-07 · Modified 2026-03-03

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CVSS v3

—

CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N

CVSS v4 NEW

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not yet in upstream

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

No mitigations published for this CVE yet.

The vendor-content worker queues fetches as references arrive (check back in a few minutes). Or — if you've already worked around this in production — publish your fix to the community-verified tier.

✚ Propose a mitigation on Community → Mitigations published via the community go through AI scoring + 2 human reviewers + 7-day silent objection window before landing here with source_tier=community-verified.

OS impact

SUSE Affected 1 release

Version	Status	Fixed in
—	Affected	—

Arch Fixed 1 release

Version	Status	Fixed in
—	Fixed	`1.21.1-1`

Debian Fixed 5 releases

Version	Status	Fixed in
trixie	Fixed	`1.20.5+really1.20.2-1`
sid	Fixed	`1.20.5+really1.20.2-1`
forky	Fixed	`1.20.5+really1.20.2-1`
bullseye	Fixed	`1.20.5+really1.20.2-1`
bookworm	Fixed	`1.20.5+really1.20.2-1`

Package impact

Ecosystem	Package	Vulnerable	Fixed
Go	k8s.io/kubernetes	`>=1.16.0,<1.18.19`	`1.18.19`
Go	k8s.io/kubernetes	`>=1.19.0,<1.19.11`	`1.19.11`
Go	k8s.io/kubernetes	`>=1.20.0,<1.20.7`	`1.20.7`
Go	k8s.io/kubernetes	`>=1.21.0,<1.21.1`	`1.21.1`

References

Community-verified mitigations for this CVE will appear above when contributors publish them.

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