Headline
CVE-2023-5044: CVE-2023-5044: Code injection via nginx.ingress.kubernetes.io/permanent-redirect annotation · Issue #10572 · kubernetes/ingress-nginx
Code injection via nginx.ingress.kubernetes.io/permanent-redirect annotation.
Issue Details
A security issue was identified in ingress-nginx where the nginx.ingress.kubernetes.io/permanent-redirect annotation on an Ingress object (in the networking.k8s.io or extensions API group) can be used to inject arbitrary commands, and obtain the credentials of the ingress-nginx controller. In the default configuration, that credential has access to all secrets in the cluster.
This issue has been rated High (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:L), and assigned CVE-2023-5044.
Affected Components and Configurations
This bug affects ingress-nginx. If you do not have ingress-nginx installed on your cluster, you are not affected. You can check this by running kubectl get po -n ingress-nginx.
If you are running the “chrooted” ingress-nginx controller introduced in v1.2.0 (gcr.io/k8s-staging-ingress-nginx/controller-chroot), command execution is possible but credential extraction is not, so the High severity does not apply.
Multi-tenant environments where non-admin users have permissions to create Ingress objects are most affected by this issue.
Affected Versions
- <v1.9.0
Versions allowing mitigation
- v1.9.0
Mitigation
Ingress Administrators should set the --enable-annotation-validation flag to enforce restrictions on the contents of ingress-nginx annotation fields.
Detection
If you find evidence that this vulnerability has been exploited, please contact [email protected]
Additional Details
See ingress-nginx Issue #10572 for more details.
Acknowledgements
This vulnerability was reported by Jan-Otto Kröpke (Cloudeteer GmbH)
Thank You,
CJ Cullen on behalf of the Kubernetes Security Response Committee
Related news
Three unpatched high-severity security flaws have been disclosed in the NGINX Ingress controller for Kubernetes that could be weaponized by a threat actor to steal secret credentials from the cluster. The vulnerabilities are as follows - CVE-2022-4886 (CVSS score: 8.8) - Ingress-nginx path sanitization can be bypassed to obtain the credentials of the ingress-nginx controller CVE-2023-5043 (