A security issue was discovered in ingress-nginx where the protection afforded by the auth-url Ingress annotation may not be effective in the presence of a specific misconfiguration.

If the ingress-nginx controller is configured with a default custom-errors configuration that includes HTTP errors 401 or 403, and if the configured default custom-errors backend is defective and fails to respect the X-Code HTTP header, then an Ingress with the auth-url annotation may be accessed even when authentication fails.

Note that the built-in custom-errors backend works correctly. To trigger this issue requires an administrator to specifically configure ingress-nginx with a broken external component.

A security issue was discovered in ingress-nginx cthe rules.http.paths.path Ingress field can be used to inject configuration into nginx. This can lead to arbitrary code execution in the context of the ingress-nginx controller, and disclosure of Secrets accessible to the controller. (Note that in the default installation, the controller can access all Secrets cluster-wide.)