Contrast, Edgeless Systems' runtime for confidential containers on Kubernetes, is affected in versions up to and including 1.9.0. The VOLUME directive in a Dockerfile (config.volumes in the OCI image configuration) is only a hint and is not handled specially by Kubernetes, but containerd adds a mount point for it when Kubernetes sets none, requiring the runtime to be able to push arbitrary data to the Kata agent. As a result, on bare-metal Contrast deployments (AKS deployments are not affected) that run an image declaring at least one VOLUME for which no Kubernetes mount exists at that path, the untrusted host can write arbitrary file trees below that mount point inside the confidential container, compromising the integrity of a directory that is typically important to the application's core functionality. Version 1.9.1 fixes the issue by disallowing this configuration in `contrast generate`.
| Métrique | Valeur | Interprétation |
|---|---|---|
|
AV (Vecteur d'Attaque)
Attack Vector
|
Adjacent (A)
|
Exploit nécessite un accès au segment réseau local |
|
AC (Complexité d'Attaque)
Attack Complexity
|
Low (L)
|
Peu de conditions requises 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
|
Low (L)
|
Modification limitée des données possible |
|
A (Impact Disponibilité)
Availability Impact
|
None (N)
|
Aucune interruption de service |
Edgeless Systems Contrast before 1.9.1 Insecure Volume Mount