CVE-2023-35936
Vulnérabilité moyenne dans pandoc (jgm)
Description
Pandoc is a Haskell library for converting from one markup format to another, and a command-line tool that uses this library. Starting in version 1.13 and prior to version 3.1.4, Pandoc is susceptible to an arbitrary file write vulnerability, which can be triggered by providing a specially crafted image element in the input when generating files using the `--extract-media` option or outputting to PDF format. This vulnerability allows an attacker to create or overwrite arbitrary files on the system ,depending on the privileges of the process running pandoc. It only affects systems that pass untrusted user input to pandoc and allow pandoc to be used to produce a PDF or with the `--extract-media` option. The fix is to unescape the percent-encoding prior to checking that the resource is not above the working directory, and prior to extracting the extension. Some code for checking that the path is below the working directory was flawed in a similar way and has also been fixed. Note that the `--sandbox` option, which only affects IO done by readers and writers themselves, does not block this vulnerability. The vulnerability is patched in pandoc 3.1.4. As a workaround, audit the pandoc command and disallow PDF output and the `--extract-media` option.
Gravité et risque d'exploitation
CVE-2023-35936 obtient un score CVSS de 6.0/10, soit une gravité moyenne. Selon le modèle EPSS, la probabilité qu'elle soit exploitée dans les 30 prochains jours est de 0.37 %, ce qui la place devant 29.2 % des CVE référencées.
Que faire ?
- Vérifiez si pandoc (versions >= 1.13, < 3.1.4) 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/jgm/pandoc/security/advisories/GHSA-xj5q-fv23-575g
- https://lists.debian.org/debian-lts-announce/2023/07/msg00029.html
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/QI6RBP6ZKVC2OOCV6SU2FUHPMAXDDJFU/
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/JGRJHU2FTSGTHHRTNDF7STEKLKKA25JN/
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/LYP3FKDS3KAYMQUZVVL73IUI4CWSKLKP/
