Confidential Containers Guest Components provides guest tools and components for confidential container workloads. From 0.16.0 until 0.20.0, a crafted OCI image layer can make image_rs::stream::unpack::unpack() create a hardlink outside its destination directory. In image-rs/src/stream/unpack.rs, try_hardlink_fallback() validates the hardlink source but computes the destination with destination.join(&entry_rel). Rust Path::join replaces the base when entry_rel is an absolute tar entry path, so fs::hard_link(&src_canon, &dst_entry_abs) can write attacker-controlled content to an arbitrary absolute path. In Confidential Containers the workload owner already controls trusted image content, so the issue is a workload-owner escape into the pod virtual machine rather than a crossing of the image trust boundary, but it may enable access to pod virtual machine capabilities and attestation abuse. This issue is fixed in version 0.20.0.
| Métrique | Valeur | Interprétation |
|---|---|---|
|
AV (Vecteur d'Attaque)
Attack Vector
|
Network (N)
|
Exploit possible à distance via réseau (HTTP, API, etc.) |
|
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
|
Changed (C)
|
Impact s'étend au-delà du composant compromis |
|
C (Impact Confidentialité)
Confidentiality Impact
|
Low (L)
|
Divulgation limitée 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 |
Confidential Containers Guest Components image-rs: zip-slip-class arbitrary file write via absolute entry path in hardlink fallback