gitoxide is an implementation of git written in Rust. Prior to 0.21.1, a malicious tree can be constructed that will, when checked out with gitoxide, permit writing an attacker-controlled symlink into any existing directory the user has write access to. During checkout, all symlink index entries are deferred and created after regular files using a single shared gix_worktree::Stack. Internally, this uses a gix_fs::Stack. gix_fs::Stack::make_relative_path_current() caches validated path prefixes: when the previously-processed leaf component exactly matches the leading component(s) of the next path, the leaf-to-directory transition at gix-fs/src/stack.rs invokes only delegate.push_directory(), never delegate.push(). In gix_worktree::stack::delegate::StackDelegate, when the state member is State::CreateDirectoryAndAttributesStack, Attributes::push_directory() only loads attributes (from the ODB, in the clone case), and does not perform any other checks. The on-disk symlink_metadata() check and unlink-on-collision live in StackDelegate::push()'s invocation of create_leading_directory(), which is therefore bypassed for the cached prefix. The final symlink is created with plain std::os::unix::fs::symlink, which follows symlinks in parent directories. Therefore, it's possible to provide a tree with duplicate symlink and directory entries that exploits this. This vulnerability is fixed in 0.21.1.
| Métrique | Valeur | Interprétation |
|---|---|---|
|
AV (Vecteur d'Attaque)
Attack Vector
|
Local (L)
|
Exploit nécessite un accès local au système |
|
AC (Complexité d'Attaque)
Attack Complexity
|
Low (L)
|
Peu de conditions requises pour exploiter |
|
PR (Privilèges Requis)
Privileges Required
|
None (N)
|
Aucune authentification requise |
|
UI (Interaction Utilisateur)
User Interaction
|
Required (R)
|
NĂ©cessite une action utilisateur (clic lien, ouverture fichier, etc.) |
|
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
|
High (H)
|
Modification totale des données possible |
|
A (Impact Disponibilité)
Availability Impact
|
High (H)
|
Interruption totale du service possible |
gix-fs: Symlink prefix-reuse allows worktree escape during checkout