CVE-2021-25748

Name: CVE-2021-25748
Creator: NVD / NIST
Published: 2023-05-24T17:15:09.253+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 6.5/10EPSS 0.69%

Last modified Jun 17, 2026

CVE-2021-25748 is a medium-severity vulnerability rated 6.5/10 on the CVSS scale. A security issue was discovered in ingress-nginx where a user that can create or update ingress objects can use a newline character to bypass the sanitization of the `spec.rules[].http.paths[].path` field of an Ingress object (in the `networking.k8s.io` or `extensions` API group) to obtain the credentials of the ingress-nginx controller. In the default configuration, that credential has access to all secrets in the cluster.. EPSS estimates a 0.69% chance of exploitation in the next 30 days.

Description

A security issue was discovered in ingress-nginx where a user that can create or update ingress objects can use a newline character to bypass the sanitization of the `spec.rules[].http.paths[].path` field of an Ingress object (in the `networking.k8s.io` or `extensions` API group) to obtain the credentials of the ingress-nginx controller. In the default configuration, that credential has access to all secrets in the cluster.

Metrics

CVSS 3.1

6.5/10

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

EPSS Probability

0.69%

48.2th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-20

Affected Software

Vendor	Product	Versions
Kubernetes	Ingress-Nginx	< 1.2.1

References

https://github.com/kubernetes/ingress-nginx/issues/8686Issue Tracking, Mitigation, Vendor Advisory
https://groups.google.com/g/kubernetes-security-announce/c/avaRYa9c7I8Mailing List, Mitigation, Vendor Advisory
https://github.com/kubernetes/ingress-nginx/issues/8686Issue Tracking, Mitigation, Vendor Advisory
https://groups.google.com/g/kubernetes-security-announce/c/avaRYa9c7I8Mailing List, Mitigation, Vendor Advisory

Timeline

Published: May 24, 2023
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-25748?

How severe is CVE-2021-25748?

CVE-2021-25748 has a CVSS score of 6.5/10 (MEDIUM severity). The EPSS model estimates a 0.69% probability of exploitation in the next 30 days.

How do I fix CVE-2021-25748?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-25748?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST