SSHFS is a network filesystem client for connecting to SSH servers. Prior to version 3.7.6, a rogue SFTP server can return absolute symlink targets or relative targets containing parent-directory components that SSHFS passes through FUSE for resolution by the client kernel against the local filesystem. The documented transform_symlinks mitigation does not contain relative targets because transform_symlink() returns early at sshfs.c:2181, while sshfs_readlink() at sshfs.c:2234 to sshfs.c:2236 otherwise copies the server-supplied link target to the kernel. A victim or victim-side tool that follows such a link through ordinary operations such as cp, rsync, backup tooling, or an editor can disclose readable local files back to the server or write server-controlled content to writable local files, potentially including startup or scheduled-task files. This issue is fixed in version 3.7.6.
| 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
|
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
|
Changed (C)
|
Impact s'Ă©tend au-delĂ 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
|
None (N)
|
Aucune interruption de service |
SSHFS Symlink Escape: Rogue SFTP Server → Local File Read/Write