CVE-2025-38499
Medium
Elevated severity or exploit probability.
CVSS breakdown
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
| Attack Vector | L | Local |
| Attack Complexity | L | Low |
| Privileges Required | L | Low |
| User Interaction | N | None |
| Scope | U | Unchanged |
| Confidentiality | H | High |
| Integrity | H | High |
| Availability | H | High |
Timeline
- 2025-08-11 — Published (NVD)
- 2026-07-30 — Last modified (NVD)
Description
In the Linux kernel, the following vulnerability has been resolved: clone_private_mnt(): make sure that caller has CAP_SYS_ADMIN in the right userns What we want is to verify there is that clone won't expose something hidden by a mount we wouldn't be able to undo. "Wouldn't be able to undo" may be a result of MNT_LOCKED on a child, but it may also come from lacking admin rights in the userns of the namespace mount belongs to. clone_private_mnt() checks the former, but not the latter. There's a number of rather confusing CAP_SYS_ADMIN checks in various userns during the mount, especially with the new mount API; they serve different purposes and in case of clone_private_mnt() they usually, but not always end up covering the missing check mentioned above.
Affected
References
- https://git.kernel.org/stable/c/36fecd740de2d542d2091d65d36554ee2bcf9c65
- https://git.kernel.org/stable/c/38628ae06e2a37770cd794802a3f1310cf9846e3
- https://git.kernel.org/stable/c/c28f922c9dcee0e4876a2c095939d77fe7e15116
- https://git.kernel.org/stable/c/d717325b5ecf2a40daca85c61923e17f32306179
- https://git.kernel.org/stable/c/dc6a664089f10eab0fb36b6e4f705022210191d2
- https://git.kernel.org/stable/c/e77078e52fbf018ab986efb3c79065ab35025607
- https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html
- https://cert-portal.siemens.com/productcert/html/ssa-082556.html