CVE-2023-32194: Vulnerability in Granting Create/All Global Roles for Namespaces

This long-read post discusses a recently identified vulnerability (CVE-2023-32194) concerning granting create or all (*) global roles for resource type "namespaces." Regardless of the API group, the subject will receive all permissions for core namespaces. This vulnerability could potentially result in a user gaining unauthorized access, creating, updating, or deleting a namespace in the project.

2. Exploit Details

The vulnerability occurs when an administrator attempts to grant a "create" or all (*) global roles to a user or service account for a resource type of "namespaces." Instead of assigning the intended permissions, the user will receive complete access to all namespaces in the project, regardless of the designated API group.

This could enable a malicious user to view and manipulate information they should not have access to, potentially leading to information leaks, data corruption, or unauthorized control over the project's resources.

3. Code Snippet

The following JSON file snippet demonstrates what a permissions assignment might look like when granting "create" permission for resource type "namespaces" and the vulnerability:

~~~JSON
{

"kind": "ClusterRole",

"apiVersion": "rbac.authorization.k8s.io/v1",

"name": "create-namespace"

},

"rules": [

{

"apiGroups": [""]

}
]
}
~~~

Due to the vulnerability, the user granted this role will actually receive all permissions ("*") for the core namespaces, which could be exploited in unintended ways.

Here are the official references related to this vulnerability

1. CVE-2023-32194 - National Vulnerability Database (NVD)
2. Kubernetes Issue Tracker - GitHub
3. Security Advisory for Kubernetes

Make sure to visit these sources for updated information about this vulnerability.

Consider the following mitigations and recommendations to prevent exploitation of this vulnerability

1. Review role assignments: Audit all existing user and service account permissions assignments, ensuring that resource type "namespaces" is only granted necessary permissions.
2. Use predefined roles: Whenever possible, use predefined roles that come with Kubernetes, which are carefully designed to minimize security risks.
3. Apply least-privilege principle: Limit users' and service accounts' privileges to the minimum required for their roles, reducing the risk of unintended access or misuse.
4. Monitor API access: Continuously monitor API access logs to detect suspicious activities that could indicate unauthorized access or privilege escalation attempts.
5. Keep your cluster up-to-date: Regularly update your Kubernetes cluster to the latest version, which includes security patches and vulnerability fixes.

By applying these mitigations and recommendations, you can significantly reduce the risk of exposing your project to potential threats and strengthen the overall security posture of your Kubernetes environment.

Timeline

Published on: 10/16/2024 13:15:12 UTC
Last modified on: 10/16/2024 16:38:14 UTC