|
Message-ID: <CABdrxGBr+uS70N8OhVvLZ=qW8EaGLJkA84Q0vAjQ3tpv6bdX0Q@mail.gmail.com> Date: Fri, 10 Jun 2022 09:11:47 -0700 From: CJ Cullen <cjcullen@...gle.com> To: oss-security@...ts.openwall.com Subject: [kubernetes] CVE-2021-25748: Ingress-nginx `path` sanitization can be bypassed with newline character Issue Details A security issue was discovered in ingress-nginx <https://github.com/kubernetes/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. 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 <https://www.first.org/cvss/calculator/3.1#CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:L>), and assigned CVE-2021-25748. 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), you are not affected. Multitenant environments where non-admin users have permissions to create Ingress objects are most affected by this issue. Affected Versions - <v1.2.1 Fixed Versions - v1.2.1 Mitigation If you are unable to roll out the fix, this vulnerability can be mitigated by implementing an admission policy that restricts the `spec.rules[].http.paths[].path` field on the networking.k8s.io/Ingress resource to known safe characters (see the newly added rules <https://github.com/kubernetes/ingress-nginx/blame/main/internal/ingress/inspector/rules.go>, or the suggested value for annotation-value-word-blocklist <https://kubernetes.github.io/ingress-nginx/user-guide/nginx-configuration/configmap/#annotation-value-word-blocklist> ). Detection If you find evidence that this vulnerability has been exploited, please contact security@...ernetes.io Additional Details See ingress-nginx Issue #8686 <https://github.com/kubernetes/ingress-nginx/issues/8686> for more details. Acknowledgements This vulnerability was reported by Gafnit Amiga. Thank You, CJ Cullen on behalf of the Kubernetes Security Response Committee
Powered by blists - more mailing lists
Please check out the Open Source Software Security Wiki, which is counterpart to this mailing list.
Confused about mailing lists and their use? Read about mailing lists on Wikipedia and check out these guidelines on proper formatting of your messages.