4.3 Medium
CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
LOW
Integrity Impact
NONE
Availability Impact
NONE
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
4.7 Medium
AI Score
Confidence
High
0.0004 Low
EPSS
Percentile
13.9%
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.
CPE | Name | Operator | Version |
---|---|---|---|
clastix:capsule | clastix capsule | lt | 0.4.5 |
clastix:capsule-proxy | clastix capsule-proxy | lt | 0.4.5 |
[
{
"vendor": "projectcapsule",
"product": "capsule-proxy",
"versions": [
{
"version": "< 0.4.5",
"status": "affected"
}
]
}
]
4.3 Medium
CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
LOW
Integrity Impact
NONE
Availability Impact
NONE
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
4.7 Medium
AI Score
Confidence
High
0.0004 Low
EPSS
Percentile
13.9%