NVD / CVE Program· CNA XEN

CVE-2022-42332: x86 shadow plus log-dirty mode use-after-free In environments where host assisted address translation is necessary but Hardware Assisted Pag

Noroxi assessment

Priority: Monitor (action score 31/100)

The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
Probability of exploitation in the next 30 days: 0.27% (FIRST EPSS).
Someone with local access to the system can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
Fixed version: xen (Alpine:v3.15) 4.15.5-r0; xen (Alpine:v3.16) 4.16.4-r0; xen (Alpine:v3.18) 4.17.0-r5.

Low priority for now. Upgrade to xen (Alpine:v3.15) 4.15.5-r0; xen (Alpine:v3.16) 4.16.4-r0; xen (Alpine:v3.18) 4.17.0-r5 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

x86 shadow plus log-dirty mode use-after-free In environments where host assisted address translation is necessary but Hardware Assisted Paging (HAP) is unavailable, Xen will run guests in so called shadow mode. Shadow mode maintains a pool of memory used for both shadow page tables as well as auxiliary data structures. To migrate or snapshot guests, Xen additionally runs them in so called log-dirty mode. The data structures needed by the log-dirty tracking are part of aformentioned auxiliary data. In order to keep error handling efforts within reasonable bounds, for operations which may require memory allocations shadow mode logic ensures up front that enough memory is available for the worst case requirements. Unfortunately, while page table memory is properly accounted for on the code path requiring the potential establishing of new shadows, demands by the log-dirty infrastructure were not taken into consideration. As a result, just established shadow page tables could be freed again immediately, while other code is still accessing them on the assumption that they would remain allocated.

HighCVSS 7.8 · v3.1—No exploit Fix available

Memory safety

Published: Mar 21, 2023
Updated: Jun 17, 2026
EPSS: 0.2% · 19th percentile
CWE: CWE-416

Report tools

JSON

Action score

Monitor

Low priority for now.

CVSS: 31 / 40 · 7.8 / 10
CISA KEV: 0 / 30 · Not listed
EPSS: 0 / 30 · 0.2%

CISA SSVC decision

Exploitation: none
Automatable: no
Technical impact: total

Vulnrichment: CISA's decision-tree inputs.

Get told when this record changes

Not in KEV: no record of exploitation in the wild
No public exploit code on record
A fix has been released

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

Vendor	Product	CPE
xen	xen	cpe:2.3:o:xen:xen
debian	debian linux	cpe:2.3:o:debian:debian_linux
fedoraproject	fedora	cpe:2.3:o:fedoraproject:fedora

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

debian debian linux11.0
fedoraproject fedora37
fedoraproject fedora38
xen xen3.2.0 and later

Versions reported by the vendor

Affected version ranges reported by the assigning authority (XEN). Independent of NVD's CPE analysis and usually ahead of it.

Xen xen
- consult Xen advisory XSA-427unknown

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

Ecosystem	Package	Affected range	Fix
Alpine:v3.15	xen	from 3.2.0 · before 4.15.5-r0	4.15.5-r0
Alpine:v3.16	xen	from 3.2.0 · before 4.16.4-r0	4.16.4-r0
Alpine:v3.18	xen	from 3.2.0 · before 4.17.0-r5	4.17.0-r5
Debian:11	xen	before 4.14.5+94-ge49571868d-1	4.14.5+94-ge49571868d-1
Debian:12	xen	before 4.17.0+74-g3eac216e6e-1	4.17.0+74-g3eac216e6e-1
openSUSE:Leap Micro 5.3	xen	before 4.16.3_06-150400.4.25.1	4.16.3_06-150400.4.25.1
openSUSE:Tumbleweed	xen	before 4.17.0_06-1.1	4.17.0_06-1.1
SUSE:Linux Enterprise High Performance Computing 15 SP1-LTSS	xen	before 4.12.4_34-150100.3.86.1	4.12.4_34-150100.3.86.1
SUSE:Linux Enterprise High Performance Computing 15 SP2-LTSS	xen	before 4.13.4_20-150200.3.71.1	4.13.4_20-150200.3.71.1
SUSE:Linux Enterprise High Performance Computing 15 SP3-ESPOS	xen	before 4.14.5_12-150300.3.48.1	4.14.5_12-150300.3.48.1
SUSE:Linux Enterprise Micro 5.3	xen	before 4.16.3_06-150400.4.25.1	4.16.3_06-150400.4.25.1
SUSE:Linux Enterprise Server 12 SP2-BCL	xen	before 4.7.6_32-43.104.1	4.7.6_32-43.104.1
SUSE:Linux Enterprise Software Development Kit 12 SP5	xen	before 4.12.4_34-3.88.1	4.12.4_34-3.88.1
SUSE:OpenStack Cloud 9	xen	before 4.11.4_38-2.89.1	4.11.4_38-2.89.1

Same product

xen: all records

Other highest-scoring records for the same primary product.

CVE-2017-10921The grant-table feature in Xen through 4.8.x does not ensure sufficient type counts for a GNTMAP_device_map and GNTMAP_host_map mapping, whi
41Plan
CVE-2017-10920The grant-table feature in Xen through 4.8.x mishandles a GNTMAP_device_map and GNTMAP_host_map mapping, when followed by only a GNTMAP_host
41Plan
CVE-2017-10918Xen through 4.8.x does not validate memory allocations during certain P2M operations, which allows guest OS users to obtain privileged host
41Plan

Published before and after this one in the same product

← EarlierCVE-2022-42330Jan 26, 2023 · Guests can cause Xenstore crash via soft reset When a guest issues a "Soft Reset" (e.g.
30Monitor
← EarlierCVE-2022-42331Mar 21, 2023 · x86: speculative vulnerability in 32bit SYSCALL path Due to an oversight in the very original Spectre/Meltdown security work (XSA-254), one
22Monitor
Later →CVE-2022-42333Mar 21, 2023 · x86/HVM pinned cache attributes mis-handling T[his CNA information record relates to multiple CVEs; the text explains which aspects/vulnerab
34Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / package	Fixed version	Source
alpine:xen	4.15.5-r0 · Alpine:v3.15	Package registry (OSV)
debian:xen	4.17.0+74-g3eac216e6e-1 · Debian:12	Package registry (OSV)
opensuse:xen	4.16.3_06-150400.4.25.1 · openSUSE:Leap Micro 5.3	Package registry (OSV)
suse:xen	4.12.4_34-3.88.1 · SUSE:Linux Enterprise Software Development Kit 12 SP5	Package registry (OSV)
suse:xen	4.16.3_06-150400.4.25.1 · SUSE:Linux Enterprise Micro 5.3	Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

Jan BeulichSUSE.'}]}}}

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

Someone with local access to the system can trigger it.
A low-privileged account is enough.
No user action is required.
No special conditions are required; it is repeatable.

If successful

Confidentiality: high · data can be read
Integrity: high · data or configuration can be modified
Availability: high · the service can be disrupted

Attack vector: Local
Attack complexity: Low
Privileges required: Low
User interaction: None
Scope: Unchanged
Confidentiality impact: High
Integrity impact: High
Availability impact: High

Weakness class (CWE)

CWE-416 · Use After Free

CVSS vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

nvd-primary

Root cause

After a memory region is freed, another reference pointing to it is still used. By then, the same region may have been allocated for different data.

The bug in code

The whole CWE-416 class

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

Vulnerable

1free(dev->buf);
2/* ... another thread is still running ... */
3process(dev->buf);

Fixed

1lock(&dev->lock);
2free(dev->buf);
3dev->buf = NULL;
4unlock(&dev->lock);

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

Fix✗ → ✓Sep 28, 2026, 10:46 PM UTC

For records you follow, these changes also arrive as notifications. →

References

www.openwall.com/lists/oss-security/2023/03/21/1

Show all references (6 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records