CVE-2023-46254 Service accounts can see namespaces of other tenants in capsule-proxy
Tenant owners can list namespaces of other tenants with identical ServiceAccount names, exposing infrastructure metadata.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2023-46254?
CVE-2023-46254 is a medium-severity vulnerability in projectcapsule capsule-proxy, published on 6 Nov 2023. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
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 doesn't 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.
Weakness: CWE-200
Which versions are affected by CVE-2023-46254?
4 open source packages ship an affected version, including github.com/projectcapsule/capsule-proxy and github.com/projectcapsule/capsule. It affects 2 products.
| Package | Affected | Fixed in |
|---|---|---|
github.com/projectcapsule/capsule-proxy Go | All versions | 0.4.5 |
github.com/projectcapsule/capsule-proxy Go | All versions | 0.4.5 |
github.com/projectcapsule/capsule Go | All versions | 0.4.5 |
github.com/projectcapsule/capsule Go | All versions | 0.4.5 |
Products include Clastix Capsule, Clastix Capsule-Proxy.
How do I fix CVE-2023-46254?
Upgrade github.com/projectcapsule/capsule-proxy to 0.4.5 or later.
Is CVE-2023-46254 being exploited?
There is no known exploitation of CVE-2023-46254 in the wild and no public exploit code.
Other vulnerabilities in projectcapsule capsule-proxy
Sources
Also known as GHSA-6758-979h-249x.