Contrast is a Kubernetes runtime for confidential containers. In versions before 1.12.1, the secure persistent volume feature is vulnerable to a malicious host supplying a crafted LUKS2 volume to a pod VM. LUKS2 volume metadata is not authenticated and, with cryptsetup versions prior to 2.8.1, a header specifying the null keyslot encryption algorithm (cipher_null-ecb) is accepted without error. Because the Contrast Initializer assumes a device is protected if `cryptsetup open` succeeds with the secret seed, the guest will open the attacker-supplied volume and write secret data in plaintext, or under a volume key known to the attacker, allowing the host to read confidential data that should have been encrypted. Contrast v1.12.1 ships cryptsetup 2.8.1, which disables null ciphers in keyslots when the passphrase is non-empty; v1.13.0 adds detached-header validation in guest memory and integrity protection for secure persistent storage. Contrast persistent volumes were not integrity protected, so integrity impact is not considered.
| 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
|
High (H)
|
Divulgation totale d'informations |
|
I (Impact Intégrité)
Integrity Impact
|
None (N)
|
Aucune modification de données possible |
|
A (Impact Disponibilité)
Availability Impact
|
None (N)
|
Aucune interruption de service |
Contrast before 1.12.1 Insecure LUKS2 Persistent Storage