CVE-2023-46254
capsule-proxy service discloses Namespaces of colliding tenants to owners of different tenants with the same ServiceAccount name
Impact
### Summary 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. ### Details - 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` > Please, notice the same ServiceAccount name, although in different namespaces. 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`) 2. Tenant owners are ServiceAccount, with the same resource name, but in different Namespaces. The CVE doesn't allow any privilege escalation on the outer tenant Namespace-scoped resources, since the Kubernetes RBAC is enforcing this.
Affected packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| go | github.com/projectcapsule/capsule | <= 0.4.4 | 0.4.5 |
| go | github.com/projectcapsule/capsule-proxy | <= 0.4.4 | 0.4.5 |
Affected products
| Vendor | Product | Affected versions |
|---|---|---|
| Clastix | Capsule | before 0.4.5 |
| Clastix | Capsule-Proxy | before 0.4.5 |
Weakness classification
References
- NVD record
- CVE.org record
- GitHub advisory
- https://github.com/projectcapsule/capsule-proxy/commit/615202f7b02eaec7681336bd63daed1f39ae00c5
- https://github.com/projectcapsule/capsule-proxy/security/advisories/GHSA-6758-979h-249x
- https://github.com/advisories/GHSA-6758-979h-249x
- https://nvd.nist.gov/vuln/detail/CVE-2023-46254
- https://github.com/projectcapsule/capsule-proxy/releases/tag/v0.4.5