CVE-2025-40362
Vulnérabilité élevée dans Linux (Linux)
Description
In the Linux kernel, the following vulnerability has been resolved: ceph: fix multifs mds auth caps issue The mds auth caps check should also validate the fsname along with the associated caps. Not doing so would result in applying the mds auth caps of one fs on to the other fs in a multifs ceph cluster. The bug causes multiple issues w.r.t user authentication, following is one such example. Steps to Reproduce (on vstart cluster): 1. Create two file systems in a cluster, say 'fsname1' and 'fsname2' 2. Authorize read only permission to the user 'client.usr' on fs 'fsname1' $ceph fs authorize fsname1 client.usr / r 3. Authorize read and write permission to the same user 'client.usr' on fs 'fsname2' $ceph fs authorize fsname2 client.usr / rw 4. Update the keyring $ceph auth get client.usr >> ./keyring With above permssions for the user 'client.usr', following is the expectation. a. The 'client.usr' should be able to only read the contents and not allowed to create or delete files on file system 'fsname1'. b. The 'client.usr' should be able to read/write on file system 'fsname2'. But, with this bug, the 'client.usr' is allowed to read/write on file system 'fsname1'. See below. 5. Mount the file system 'fsname1' with the user 'client.usr' $sudo bin/mount.ceph usr@.fsname1=/ /kmnt_fsname1_usr/ 6. Try creating a file on file system 'fsname1' with user 'client.usr'. This should fail but passes with this bug. $touch /kmnt_fsname1_usr/file1 7. Mount the file system 'fsname1' with the user 'client.admin' and create a file. $sudo bin/mount.ceph admin@.fsname1=/ /kmnt_fsname1_admin $echo "data" > /kmnt_fsname1_admin/admin_file1 8. Try removing an existing file on file system 'fsname1' with the user 'client.usr'. This shoudn't succeed but succeeds with the bug. $rm -f /kmnt_fsname1_usr/admin_file1 For more information, please take a look at the corresponding mds/fuse patch and tests added by looking into the tracker mentioned below. v2: Fix a possible null dereference in doutc v3: Don't store fsname from mdsmap, validate against ceph_mount_options's fsname and use it v4: Code refactor, better warning message and fix possible compiler warning [ Slava.Dubeyko: "fsname check failed" -> "fsname mismatch" ]
Gravité et risque d'exploitation
CVE-2025-40362 obtient un score CVSS de 8.8/10, soit une gravité élevée. Selon le modèle EPSS, la probabilité qu'elle soit exploitée dans les 30 prochains jours est de 0.16 %, ce qui la place devant 5.2 % des CVE référencées.
Que faire ?
- Vérifiez si Linux (versions <ca3da8b27ab9a0923ad477447cfb8fc7f4b4c523, <07640d34a781bb2e39020a39137073c03c4aa932, <=*, <=6.12.*, <22c73d52a6d05c5a2053385c0d6cd9984732799d, <=6.17.*, 6.10, 6.18, 6.17.8, 596afb0b8933ba6ed7227adcc538db26feb25c74, 0, 6.12.58, <6.10) 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.