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CVE-2023-53503

Vulnérabilité non évaluée dans Linux (Linux)

CVSS 0.0 · Non évaluée
EPSS 0.2%
Linux•Linux•Versions : <=6.1.*, 5.10.181, 3.11, <3.11, 0, <31668cebf45adfb6283e465e641c4f5a21b07afa, <=6.3.*, 6.4, 6.3.4, <620a3c28221bb219b81bc0bffd065cc187494302, <=5.10.*, 6.1.30, <b4319e457d6e3fb33e443efeaf4634fc36e8a9ed, <100c0ad6c04597fefeaaba2bb1827cc015d95067, <5354b2af34064a4579be8bc0e2f15a7b70f14b5f, <=*, <=5.15.*, 5.15.113, 2f2e09eb15849562aede80ed007658e4504ded26

Description

In the Linux kernel, the following vulnerability has been resolved: ext4: allow ext4_get_group_info() to fail Previously, ext4_get_group_info() would treat an invalid group number as BUG(), since in theory it should never happen. However, if a malicious attaker (or fuzzer) modifies the superblock via the block device while it is the file system is mounted, it is possible for s_first_data_block to get set to a very large number. In that case, when calculating the block group of some block number (such as the starting block of a preallocation region), could result in an underflow and very large block group number. Then the BUG_ON check in ext4_get_group_info() would fire, resutling in a denial of service attack that can be triggered by root or someone with write access to the block device. For a quality of implementation perspective, it's best that even if the system administrator does something that they shouldn't, that it will not trigger a BUG. So instead of BUG'ing, ext4_get_group_info() will call ext4_error and return NULL. We also add fallback code in all of the callers of ext4_get_group_info() that it might NULL. Also, since ext4_get_group_info() was already borderline to be an inline function, un-inline it. The results in a next reduction of the compiled text size of ext4 by roughly 2k.

Gravité et risque d'exploitation

CVE-2023-53503 obtient un score CVSS de 0.0/10, soit une gravité non évaluée. Selon le modèle EPSS, la probabilité qu'elle soit exploitée dans les 30 prochains jours est de 0.15 %, ce qui la place devant 4.3 % des CVE référencées.

Que faire ?

  • Vérifiez si Linux (versions <=6.1.*, 5.10.181, 3.11, <3.11, 0, <31668cebf45adfb6283e465e641c4f5a21b07afa, <=6.3.*, 6.4, 6.3.4, <620a3c28221bb219b81bc0bffd065cc187494302, <=5.10.*, 6.1.30, <b4319e457d6e3fb33e443efeaf4634fc36e8a9ed, <100c0ad6c04597fefeaaba2bb1827cc015d95067, <5354b2af34064a4579be8bc0e2f15a7b70f14b5f, <=*, <=5.15.*, 5.15.113, 2f2e09eb15849562aede80ed007658e4504ded26) 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

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