Open Redirect in Kubernetes

CVE-2021-25737

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.

EPSS: 0.013 (68.2th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 2.7 (Low). Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:L/I:N/A:N.

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2021-25737?
CVE-2021-25737 is a low-severity vulnerability in Kubernetes, classified under Incomplete List of Disallowed Inputs. CVSS score: 2.7/10. Published 2021-09-06.
How severe is CVE-2021-25737?
Low severity. CVSS v3 base score is 2.7 out of 10.
Is CVE-2021-25737 known to be exploited?
13 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.