CVE-2023-5043

Ingress nginx annotation injection causes arbitrary command execution.

Ingress nginx annotation injection causes arbitrary command execution.

Issue Details

A security issue was identified in ingress-nginx where the nginx.ingress.kubernetes.io/configuration-snippet 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-2023-5043.

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 #10571 for more details.

Acknowledgements

This vulnerability was reported by suanve

Thank You, CJ Cullen on behalf of the Kubernetes Security Response Committee

Ingress nginx annotation injection causes arbitrary command execution.

Ingress nginx annotation injection causes arbitrary command execution.

Issue Details

A security issue was identified in ingress-nginx where the nginx.ingress.kubernetes.io/configuration-snippet 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-2023-5043.

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 #10571 for more details.

Acknowledgements

This vulnerability was reported by suanve

Thank You, CJ Cullen on behalf of the Kubernetes Security Response Committee