CVE-2023-46839

pci: phantom functions assigned to incorrect contexts

MEDIUM
5.3
CVSS Score
Published: March 20, 2024 at 10:35 AM UTC
Updated: June 17, 2026 at 06:31 AM UTC
2 products affected across 2 vendorsFedoraXen

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Severity
MEDIUM5.3
Exploit prediction
EPSS 0.8%
SSVC
No known exploit

Description

PCI devices can make use of a functionality called phantom functions, that when enabled allows the device to generate requests using the IDs of functions that are otherwise unpopulated. This allows a device to extend the number of outstanding requests. Such phantom functions need an IOMMU context setup, but failure to setup the context is not fatal when the device is assigned. Not failing device assignment when such failure happens can lead to the primary device being assigned to a guest, while some of the phantom functions are assigned to a different domain.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

Xen· Xenwordpress-plugin
95%
All versions
Vendor states this is fixed in consult Xen advisory XSA-449 (unknown)

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

References (3)

PatchVendor Advisory
Source: af854a3a-2127-422b-91ae-364da2661108
http://xenbits.xen.org/xsa/advisory-449.html
Mailing ListThird Party Advisory
Source: af854a3a-2127-422b-91ae-364da2661108
https://lists.fedoraproject.org/archives/list/[email protected]/message/XLL6SQ6IKFYXLYWITYZCRV5IBRK5G35R/

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

5.3MEDIUMCISA-ADP
Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
LOW
Integrity
NONE
Availability
NONE
Vector?

Quick Info

StatusANALYZED
CWE
NVD-CWE-noinfo

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