ClearanceKit intercepts file-system access events on macOS and enforces per-process access policies. The ECDSA private key used to sign the on-disk policy database (`/Library/Application Support/clearancekit/store.db`) is stored in the macOS System Keychain. The key was created via the two-step pattern `SecKeyCreateRandomKey` (in-memory) followed by `SecItemAdd(kSecValueRef:, kSecAttrAccess:)` (persist). Prior to version 5.0.10, for `kSecClassKey` items in the legacy System Keychain, `kSecAttrAccess` passed to `SecItemAdd` is silently ignored — the persisted key inherits no ACL restriction. The same access builder applied to `kSecClassGenericPassword` items correctly binds the ACL, making this bug specific to the EC key. The result is that any process running as root can use the key to produce valid signatures over arbitrary policy content. Version 5.0.10 fixes the issue. No known workarounds are available. Disabling the system extension and manually removing the System Keychain item labelled `clearancekit policy signing key` would prevent the forged-signature path but also disables policy enforcement.
| Métrique | Valeur | Interprétation |
|---|---|---|
|
AV (Vecteur d'Attaque)
Attack Vector
|
Local (L)
|
Exploit nécessite un accès local au système |
|
AC (Complexité d'Attaque)
Attack Complexity
|
Low (L)
|
Peu de conditions requises pour exploiter |
|
PR (Privilèges Requis)
Privileges Required
|
High (H)
|
Authentifié avec privilèges administratifs |
|
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
|
High (H)
|
Modification totale des données possible |
|
A (Impact Disponibilité)
Availability Impact
|
None (N)
|
Aucune interruption de service |
ClearanceKit: Policy signing key in System Keychain has permissive ACL allowing any local-root process to forge signed policy