CVE-2022-31163
Vulnérabilité élevée dans tzinfo (tzinfo)
Description
TZInfo is a Ruby library that provides access to time zone data and allows times to be converted using time zone rules. Versions prior to 0.36.1, as well as those prior to 1.2.10 when used with the Ruby data source tzinfo-data, are vulnerable to relative path traversal. With the Ruby data source, time zones are defined in Ruby files. There is one file per time zone. Time zone files are loaded with `require` on demand. In the affected versions, `TZInfo::Timezone.get` fails to validate time zone identifiers correctly, allowing a new line character within the identifier. With Ruby version 1.9.3 and later, `TZInfo::Timezone.get` can be made to load unintended files with `require`, executing them within the Ruby process. Versions 0.3.61 and 1.2.10 include fixes to correctly validate time zone identifiers. Versions 2.0.0 and later are not vulnerable. Version 0.3.61 can still load arbitrary files from the Ruby load path if their name follows the rules for a valid time zone identifier and the file has a prefix of `tzinfo/definition` within a directory in the load path. Applications should ensure that untrusted files are not placed in a directory on the load path. As a workaround, the time zone identifier can be validated before passing to `TZInfo::Timezone.get` by ensuring it matches the regular expression `\A[A-Za-z0-9+\-_]+(?:\/[A-Za-z0-9+\-_]+)*\z`.
Gravité et risque d'exploitation
CVE-2022-31163 obtient un score CVSS de 7.5/10, soit une gravité élevée. Selon le modèle EPSS, la probabilité qu'elle soit exploitée dans les 30 prochains jours est de 2.45 %, ce qui la place devant 84.1 % des CVE référencées.
Que faire ?
- Vérifiez si tzinfo (versions < 0.3.61, >= 1.0.0, < 1.2.10) est présent sur votre parc.
- Appliquez le correctif ou la version corrigée indiqués dans les références de l'éditeur.
- À défaut de correctif, limitez l'exposition (filtrage réseau, désactivation du composant).
- Automatisez la détection : les agents CVE Heimdall (gratuits, open source) corrèlent l'inventaire de vos serveurs avec la base CVE.
Références
- https://github.com/tzinfo/tzinfo/security/advisories/GHSA-5cm2-9h8c-rvfx
- https://github.com/tzinfo/tzinfo/releases/tag/v0.3.61
- https://github.com/tzinfo/tzinfo/releases/tag/v1.2.10
- https://github.com/tzinfo/tzinfo/commit/9eddbb5c0e682736f61d0dd803b6031a5db9eadf
- https://github.com/tzinfo/tzinfo/commit/9905ca93abf7bf3e387bd592406e403cd18334c7
- https://lists.debian.org/debian-lts-announce/2022/08/msg00009.html