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Fencer Vulns
high 7.8

CVE-2023-34322 json

top-level shadow reference dropped too early for 64-bit PV guests

published 2024-01-05 2 y ago modified 2026-06-17 4 mo ago also EUVD-2023-38403

cvss
7.8
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 12%
public exploits
0
none known

Summary

For migration as well as to work around kernels unaware of L1TF (see XSA-273), PV guests may be run in shadow paging mode. Since Xen itself needs to be mapped when PV guests run, Xen and shadowed PV guests run directly the respective shadow page tables. For 64-bit PV guests this means running on the shadow of the guest root page table.

In the course of dealing with shortage of memory in the shadow pool associated with a domain, shadows of page tables may be torn down. This tearing down may include the shadow root page table that the CPU in question is presently running on. While a precaution exists to supposedly prevent the tearing down of the underlying live page table, the time window covered by that precaution isn't large enough.

Patch / fix

  • xen xen 4.15.0
  • xen Debian 12 4.17.2+76-ge1f9cb16e2-1~deb12u1
  • xen Debian 14, Debian 13 4.17.2+55-g0b56bed864-1

debian advisories DEBIAN-CVE-2023-34322

  • xen SLE Module for Server Applications 15 SP4, SLE Module for Basesystem 15 SP4, SLE Micro 5.4 +4 more 4.16.5_08-150400.4.40.1
  • xen SLE Module for Server Applications 15 SP5, SLE Module for Basesystem 15 SP5, SLE Micro 5.5 +1 more 4.17.2_08-150500.3.15.1
  • xen SLES for SAP 15 SP3, SLES 15 SP3-LTSS, SLE Micro 5.2 +6 more 4.14.6_04-150300.3.54.1
  • xen SLES for SAP 12 SP5, SLES 12 SP5, SLE Software Development Kit 12 SP5 4.12.4_38-3.94.1
  • xen SLE Module for Server Applications 15 SP4, SLE Module for Basesystem 15 SP4, SLE Micro 5.4 +2 more 4.16.5_04-150400.4.34.1
  • xen SLE Module for Server Applications 15 SP5, SLE Module for Basesystem 15 SP5, openSUSE Leap 15.5 4.17.2_04-150500.3.9.1
  • xen SLES for SAP 15 SP1, SLES 15 SP1-LTSS, SLE High Performance Computing 15 SP1-LTSS 4.12.4_38-150100.3.92.1
  • xen SLES for SAP 15 SP2, SLES 15 SP2-LTSS, SLE High Performance Computing 15 SP2-LTSS 4.13.5_04-150200.3.77.1

suse advisories SUSE-SU-2023:4476-1SUSE-SU-2023:4475-1SUSE-SU-2023:3903-1SUSE-SU-2023:3902-1SUSE-SU-2023:3895-1SUSE-SU-2023:3894-1

  • xen openSUSE Tumbleweed 4.17.2_04-1.1

opensuse advisories openSUSE-SU-2024:13257-1

  • xen Alpine 3.15 4.15.5-r1
  • xen Alpine 3.17, Alpine 3.16 4.16.5-r1
  • xen Alpine 3.24, Alpine 3.23, Alpine 3.22 +4 more 4.17.2-r1

alpine advisories ALPINE-CVE-2023-34322

Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

CISA SSVC

Exploitation
none
Automatable
yes
Technical impact
partial
Assessed
2 y ago

Exploit prediction

0.22% chance of exploitation in the next 30 days, higher than 12% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CISA ADP 3.1 7.8 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
NVD 3.1 7.8 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CNA 3.1 7.8 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Affected products

  • Xen Xen

Classification

Weakness
  • CWE-273 Improper Check for Dropped Privileges

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.