KubeVirt is a virtual machine management add-on for Kubernetes. Versions 1.5.3 and below, and 1.6.0 contained a flawed implementation of the Kubernetes aggregation layer's authentication flow which could enable bypass of RBAC controls. It was discovered that the virt-api component fails to correctly authenticate the client when receiving API requests over mTLS. In particular, it fails to validate the CN (Common Name) field in the received client TLS certificates against the set of allowed values defined in the extension-apiserver-authentication configmap. Failre to validate certain fields in the client TLS certificate may allow an attacker to bypass existing RBAC controls by directly communicating with the aggregated API server, impersonating the Kubernetes API server and its aggregator component. This issue is fixed in versions 1.5.3 and 1.6.1.
| Métrique | Valeur | Interprétation |
|---|---|---|
|
AV (Vecteur d'Attaque)
Attack Vector
|
Local (L)
|
Exploit nécessite un accès local au système |
|
AC (Complexité d'Attaque)
Attack Complexity
|
High (H)
|
Conditions spécifiques doivent être réunies pour exploiter |
|
PR (Privilèges Requis)
Privileges Required
|
Low (L)
|
Authentifié avec compte utilisateur basique |
|
UI (Interaction Utilisateur)
User Interaction
|
None (N)
|
Aucune interaction utilisateur nécessaire |
|
S (Périmètre)
Scope
|
Unchanged (U)
|
Impact reste dans le périmètre du composant compromis |
|
C (Impact Confidentialité)
Confidentiality Impact
|
None (N)
|
Aucune divulgation d'informations |
|
I (Impact Intégrité)
Integrity Impact
|
None (N)
|
Aucune modification de données possible |
|
A (Impact Disponibilité)
Availability Impact
|
High (H)
|
Interruption totale du service possible |
KubeVirt Affected by an Authentication Bypass in Kubernetes Aggregation Layer