CVE-2021-25748: Ingress-nginx `path` sanitization can be bypassed with newline character
First published: Wed May 24 2023(Updated: )
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.
Credit: jordan@liggitt.net jordan@liggitt.net
| Affected Software | Affected Version | How to fix |
|---|---|---|
| go/k8s.io/ingress-nginx | <1.2.1 | 1.2.1 |
| Kubernetes ingress-nginx | <1.2.1 |
Never miss a vulnerability like this again
Sign up to SecAlerts for real-time vulnerability data matched to your software, aggregated from hundreds of sources.
Reference Links
- https://nvd.nist.gov/vuln/detail/CVE-2021-25748
- https://github.com/kubernetes/ingress-nginx/issues/8686
- https://groups.google.com/g/kubernetes-security-announce/c/avaRYa9c7I8
- https://github.com/kubernetes/ingress-nginx/pull/8623
- https://github.com/kubernetes/ingress-nginx/releases/tag/controller-v1.2.1
- https://github.com/advisories/GHSA-863x-868h-968x (Advisory)
Frequently Asked Questions
What is CVE-2021-25748?
CVE-2021-25748 is a security vulnerability in ingress-nginx that allows a user to bypass sanitization and obtain credentials by using a newline character in the 'spec.rules[].http.paths[].path' field of an Ingress object.
What is the severity of CVE-2021-25748?
The severity of CVE-2021-25748 is medium with a CVSS score of 6.5.
How can a user exploit CVE-2021-25748?
A user can exploit CVE-2021-25748 by creating or updating ingress objects and using a newline character in the 'spec.rules[].http.paths[].path' field.
Which software is affected by CVE-2021-25748?
The software affected by CVE-2021-25748 is the k8s.io/ingress-nginx package version up to exclusive 1.2.1 and Kubernetes Ingress-nginx version up to exclusive 1.2.1.
How do I remediate CVE-2021-25748?
To remediate CVE-2021-25748, update the k8s.io/ingress-nginx package to version 1.2.1 or higher.
- collector/github-advisory
- alias/GHSA-863x-868h-968x
- alias/CVE-2021-25748
- collector/github-advisory-latest
- package-manager/go
- collector/nvd-latest
- collector/nvd-index
- collector/nvd-cve
- agent/author
- agent/references
- agent/type
- agent/softwarecombine
- collector/mitre-cve
- source/MITRE
- agent/last-modified-date
- agent/severity
- agent/weakness
- agent/title
- agent/description
- agent/first-publish-date
- agent/event
- agent/tags
- agent/trending
- vendor/kubernetes
- canonical/kubernetes ingress-nginx