Overview
- 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.
- Source
- security-advisories@github.com
- NVD status
- Analyzed
Risk scores
CVSS 3.1
- Type
- Primary
- Base score
- 4.3
- Impact score
- 1.4
- Exploitability score
- 2.8
- Vector string
- CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
- Severity
- MEDIUM
Weaknesses
- nvd@nist.gov
- NVD-CWE-noinfo
- security-advisories@github.com
- CWE-200
Social media
- Hype score
- Not currently trending
Configurations
[
{
"nodes": [
{
"negate": false,
"cpeMatch": [
{
"criteria": "cpe:2.3:a:clastix:capsule:*:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "0A4C4DC0-2E0E-4FA7-92DA-30E31FC51CC9",
"versionEndExcluding": "0.4.5"
},
{
"criteria": "cpe:2.3:a:clastix:capsule-proxy:*:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "ECFAD73A-15CD-473C-8D55-645E5E5E395F",
"versionEndExcluding": "0.4.5"
}
],
"operator": "OR"
}
]
}
]