certfr_avis - certfr-2026-avi-0347

CERTFR-2026-AVI-0347

Vulnerability from certfr_avis

Une vulnérabilité a été découverte dans Xen. Elle permet à un attaquant de provoquer un contournement de la politique de sécurité.

Solutions

Se référer au bulletin de sécurité de l'éditeur pour l'obtention des correctifs (cf. section Documentation).

Impacted products

	Vendor	Product	Description
	XEN	Xen	Xen sur Linux sans les correctifs de sécurité xsa482-linux-1.patch et xsa482-linux-2.patch

References

Title

Publication Time

CVE-2026-31788 (GCVE-0-2026-31788)

Vulnerability from cvelistv5

Published

2026-03-25 10:25

Modified

2026-04-13 06:08

Severity ?

8.2 (High) - CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H

Summary

In the Linux kernel, the following vulnerability has been resolved: xen/privcmd: restrict usage in unprivileged domU The Xen privcmd driver allows to issue arbitrary hypercalls from user space processes. This is normally no problem, as access is usually limited to root and the hypervisor will deny any hypercalls affecting other domains. In case the guest is booted using secure boot, however, the privcmd driver would be enabling a root user process to modify e.g. kernel memory contents, thus breaking the secure boot feature. The only known case where an unprivileged domU is really needing to use the privcmd driver is the case when it is acting as the device model for another guest. In this case all hypercalls issued via the privcmd driver will target that other guest. Fortunately the privcmd driver can already be locked down to allow only hypercalls targeting a specific domain, but this mode can be activated from user land only today. The target domain can be obtained from Xenstore, so when not running in dom0 restrict the privcmd driver to that target domain from the beginning, resolving the potential problem of breaking secure boot. This is XSA-482 --- V2: - defer reading from Xenstore if Xenstore isn't ready yet (Jan Beulich) - wait in open() if target domain isn't known yet - issue message in case no target domain found (Jan Beulich)

References

URL

Tags

	https://git.kernel.org/stable/c/87a803edb2ded911cb587c53bff179d2a2ed2a28
	https://git.kernel.org/stable/c/1879319d790f7d57622cdc22807b60ea78b56b6d
	https://git.kernel.org/stable/c/78432d8f0372c71c518096395537fa12be7ff24e
	https://git.kernel.org/stable/c/389bae9a4409934e8b8d4dbdaaf02a3ae71cf8e4
	https://git.kernel.org/stable/c/cbede2e833da1893afbea9b3ff29b5dda23a4a91
	https://git.kernel.org/stable/c/453b8fb68f3641fea970db88b7d9a153ed2a37e8

Impacted products

Vendor

Product

Version

Linux

Version: 1c5de1939c204bde9cce87f4eb3d26e9f9eb732b
Version: 1c5de1939c204bde9cce87f4eb3d26e9f9eb732b
Version: 1c5de1939c204bde9cce87f4eb3d26e9f9eb732b
Version: 1c5de1939c204bde9cce87f4eb3d26e9f9eb732b
Version: 1c5de1939c204bde9cce87f4eb3d26e9f9eb732b
Version: 1c5de1939c204bde9cce87f4eb3d26e9f9eb732b

Linux

Version: 2.6.37

Show details on NVD website

JSON

To clipboard

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Sightings

Author	Source	Type	Date

Nomenclature

Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
Confirmed: The vulnerability is confirmed from an analyst perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
Patched: This vulnerability was successfully patched by the user reporting the sighting.
Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
Not confirmed: The user expresses doubt about the veracity of the vulnerability.
Not patched: This vulnerability was not successfully patched by the user reporting the sighting.

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