Rack provides an interface for developing web applications in Ruby. Prior to versions 2.2.13, 3.0.14, and 3.1.12, `Rack::Static` can serve files under the specified `root:` even if `urls:` are provided, which may expose other files under the specified `root:` unexpectedly. The vulnerability occurs because `Rack::Static` does not properly sanitize user-supplied paths before serving files. Specifically, encoded path traversal sequences are not correctly validated, allowing attackers to access files outside the designated static file directory. By exploiting this vulnerability, an attacker can gain access to all files under the specified `root:` directory, provided they are able to determine then path of the file. Versions 2.2.13, 3.0.14, and 3.1.12 contain a patch for the issue. Other mitigations include removing usage of `Rack::Static`, or ensuring that `root:` points at a directory path which only contains files which should be accessed publicly. It is likely that a CDN or similar static file server would also mitigate the issue.
| 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
|
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 |
Local File Inclusion in Rack::Static