5.5

CVE-2023-46835: x86/AMD: mismatch in IOMMU quarantine page table levels

Modified
AliasesALPINE-CVE-2023-46835UBUNTU-CVE-2023-46835DEBIAN-CVE-2023-46835
Published 05-01-2024Last modified 04-11-2025

Vulnerability summary

CVE-2023-46835 is a medium (CVSS 5.5) Out-of-bounds Write vulnerability in xen. EPSS estimates a 0.28% chance of exploitation in the next 30 days, higher than 20.9% of scored vulnerabilities.

Priority
Routine

Not severe (CVSS 5.5, local access); no exploitation reported by the 5 checked sources

Source freshness unavailable

How is this decided?
CVSS score
5.5/10
010
Medium · v3.1 (CVE.org)
EPSS score
0.28%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 8 · Related 8
OPENSUSE-SU-2024:13442-1SUSE-SU-2023:4466-1SUSE-SU-2023:4475-1SUSE-SU-2023:4476-1SUSE-SU-2023:4484-1SUSE-SU-2023:4485-1

Timeline

  1. 05-01-2024
    PublishedVulnerability first disclosed.
  2. 04-11-2025
    Last modifiedVulnerability information updated.

Description

The current setup of the quarantine page tables assumes that the quarantine domain (dom_io) has been initialized with an address width of DEFAULT_DOMAIN_ADDRESS_WIDTH (48) and hence 4 page table levels. However dom_io being a PV domain gets the AMD-Vi IOMMU page tables levels based on the maximum (hot pluggable) RAM address, and hence on systems with no RAM above the 512GB mark only 3 page-table levels are configured in the IOMMU. On systems without RAM above the 512GB boundary amd_iommu_quarantine_init() will setup page tables for the scratch page with 4 levels, while the IOMMU will be configured to use 3 levels only, resulting in the last page table directory (PDE) effectively becoming a page table entry (PTE), and hence a device in quarantine mode gaining write access to the page destined to be a PDE. Due to this page table level mismatch, the sink page the device gets read/write access to is no longer cleared between device assignment, possibly leading to data leaks.

CVSS metrics

5 scores · 5 sources · 1 version

EPSS trend

Probability

0.28%

Chance of exploitation in the next 30 days

Percentile

21%

Versus all other CVEs

30-day change

No change 0.00 pp

From 0.28% on 04-10-2026

04-10-202603-11-2026

Known exploited

Compare KEV catalogs
CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Version check

Known conditions: local access, low-privilege account, no user interaction (CVSS vector). Other conditions: not stated in public data.

Alpine1 product
  • xen< 4.15.5-r3 | < 4.16.5-r4 | < 4.17.2-r4
Debian1 product
  • xen< 4.17.2+76-ge1f9cb16e2-1~deb12u1 | < 4.17.2+76-ge1f9cb16e2-1
Ubuntu1 product
  • xenAll versions (No fix recorded)

3 vendors · 3 products

References

7 links