capsule-proxy is a reverse proxy for Capsule kubernetes multi-tenancy framework. A bug in the RoleBinding reflector used by capsule-proxy gives ServiceAccount tenant owners the right to list Namespaces of other tenants backed by the same owner kind and name. For example consider two tenants solar and wind. Tenant solar, owned by a ServiceAccount named tenant-owner in the Namespace solar. Tenant wind, owned by a ServiceAccount named tenant-owner in the Namespace wind. The Tenant owner solar would be able to list the namespaces of the Tenant wind and vice-versa, although this is not correct. The bug introduces an exfiltration vulnerability since allows the listing of Namespace resources of other Tenants, although just in some specific conditions: 1. capsule-proxy runs with the --disable-caching=false (default value: false) and 2. Tenant owners are ServiceAccount, with the same resource name, but in different Namespaces. This vulnerability doesnt allow any privilege escalation on the outer tenant Namespace-scoped resources, since the Kubernetes RBAC is enforcing this. This issue has been addressed in version 0.4.5. Users are advised to upgrade. There are no known workarounds for this vulnerability.
The product exposes sensitive information to an actor that is not explicitly authorized to have access to that information.
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Capsule | Clastix | * | 0.4.5 (excluding) |
| Capsule-proxy | Clastix | * | 0.4.5 (excluding) |
There are many different kinds of mistakes that introduce information exposures. The severity of the error can range widely, depending on the context in which the product operates, the type of sensitive information that is revealed, and the benefits it may provide to an attacker. Some kinds of sensitive information include:
Information might be sensitive to different parties, each of which may have their own expectations for whether the information should be protected. These parties include:
Information exposures can occur in different ways:
It is common practice to describe any loss of confidentiality as an “information exposure,” but this can lead to overuse of CWE-200 in CWE mapping. From the CWE perspective, loss of confidentiality is a technical impact that can arise from dozens of different weaknesses, such as insecure file permissions or out-of-bounds read. CWE-200 and its lower-level descendants are intended to cover the mistakes that occur in behaviors that explicitly manage, store, transfer, or cleanse sensitive information.