NVD / CVE Program· CNA mitre

CVE-2020-29569: An issue was discovered in the Linux kernel through 5.10.1, as used with Xen through 4.14.x.

Noroxi assessment

Priority: Monitor (action score 35/100)

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: 0.39% (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: linux-lts (Alpine:v3.13) 5.10.4-r0; linux (Debian:10) 4.19.171-2; linux (Debian:12) 5.9.15-1.

Low priority for now. Upgrade to linux-lts (Alpine:v3.13) 5.10.4-r0; linux (Debian:10) 4.19.171-2; linux (Debian:12) 5.9.15-1 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

An issue was discovered in the Linux kernel through 5.10.1, as used with Xen through 4.14.x. The Linux kernel PV block backend expects the kernel thread handler to reset ring->xenblkd to NULL when stopped. However, the handler may not have time to run if the frontend quickly toggles between the states connect and disconnect. As a consequence, the block backend may re-use a pointer after it was freed. A misbehaving guest can trigger a dom0 crash by continuously connecting / disconnecting a block frontend. Privilege escalation and information leaks cannot be ruled out. This only affects systems with a Linux blkback.

HighCVSS 8.8 · v3.1—No exploit Fix available

Published: Dec 15, 2020
Updated: Jun 16, 2026
EPSS: 0.3% · 33th percentile
CWE: CWE-416

Report tools

JSON

Action score

Monitor

Low priority for now.

CVSS: 35 / 40 · 8.8 / 10
CISA KEV: 0 / 30 · Not listed
EPSS: 0 / 30 · 0.3%

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
linux	linux kernel	cpe:2.3:o:linux:linux_kernel
netapp	hci compute node bios	cpe:2.3:o:netapp:hci_compute_node_bios
netapp	hci compute node	cpe:2.3:h:netapp:hci_compute_node
netapp	solidfire \& hci management node	cpe:2.3:a:netapp:solidfire_\&_hci_management_node
netapp	solidfire \& hci storage node	cpe:2.3:a:netapp:solidfire_\&_hci_storage_node
debian	debian linux	cpe:2.3:o:debian:debian_linux

Affected versions

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

debian debian linux10.0
debian debian linux9.0
linux linux kernel4.4.80 and later · before 4.4.254
linux linux kernel4.9.36 and later · before 4.9.249
linux linux kernel4.11.9 and later · before 4.12
linux linux kernel4.12 and later · before 4.14.213
linux linux kernel4.15 and later · before 4.19.164
linux linux kernel5.5 and later · before 5.10.4
linux linux kernel4.20 and later · before 5.4.86
linux linux kernel4.1.44 and later · before 4.2
netapp hci compute node biosall versions
netapp solidfire & hci management nodeall versions
netapp solidfire & hci storage nodeall versions
xen xenup to 4.14.1 inclusive

Package-level exposure

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

Ecosystem	Package	Affected range	Fix
Alpine:v3.13	linux-lts	before 5.10.4-r0	5.10.4-r0
Debian:10	linux	before 4.19.171-2	4.19.171-2
Debian:12	linux	before 5.9.15-1	5.9.15-1
Debian:9	linux	before 4.9.258-1	4.9.258-1
Debian:9	linux-4.19	before 4.19.171-2~deb9u1	4.19.171-2~deb9u1
openSUSE:Leap 15.1	kernel-debug	before 4.12.14-lp151.28.91.1	4.12.14-lp151.28.91.1
openSUSE:Leap 15.1	kernel-default	before 4.12.14-lp151.28.91.1	4.12.14-lp151.28.91.1
openSUSE:Leap 15.1	kernel-docs	before 4.12.14-lp151.28.91.1	4.12.14-lp151.28.91.1
openSUSE:Leap 15.1	kernel-kvmsmall	before 4.12.14-lp151.28.91.1	4.12.14-lp151.28.91.1
openSUSE:Leap 15.1	kernel-obs-build	before 4.12.14-lp151.28.91.1	4.12.14-lp151.28.91.1
openSUSE:Leap 15.1	kernel-obs-qa	before 4.12.14-lp151.28.91.1	4.12.14-lp151.28.91.1
openSUSE:Leap 15.1	kernel-source	before 4.12.14-lp151.28.91.1	4.12.14-lp151.28.91.1
openSUSE:Leap 15.1	kernel-syms	before 4.12.14-lp151.28.91.1	4.12.14-lp151.28.91.1
openSUSE:Leap 15.1	kernel-vanilla	before 4.12.14-lp151.28.91.1	4.12.14-lp151.28.91.1
openSUSE:Leap 15.2	kernel-debug	before 5.3.18-lp152.63.1	5.3.18-lp152.63.1
openSUSE:Leap 15.2	kernel-default	before 5.3.18-lp152.63.1	5.3.18-lp152.63.1
openSUSE:Leap 15.2	kernel-default-base	before 5.3.18-lp152.63.1.lp152.8.21.1	5.3.18-lp152.63.1.lp152.8.21.1
openSUSE:Leap 15.2	kernel-docs	before 5.3.18-lp152.63.1	5.3.18-lp152.63.1
openSUSE:Leap 15.2	kernel-kvmsmall	before 5.3.18-lp152.63.1	5.3.18-lp152.63.1
openSUSE:Leap 15.2	kernel-obs-build	before 5.3.18-lp152.63.1	5.3.18-lp152.63.1
openSUSE:Leap 15.2	kernel-obs-qa	before 5.3.18-lp152.63.1	5.3.18-lp152.63.1
openSUSE:Leap 15.2	kernel-preempt	before 5.3.18-lp152.63.1	5.3.18-lp152.63.1
openSUSE:Leap 15.2	kernel-source	before 5.3.18-lp152.63.1	5.3.18-lp152.63.1
openSUSE:Leap 15.2	kernel-syms	before 5.3.18-lp152.63.1	5.3.18-lp152.63.1

+96

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-2020-29567Dec 15, 2020 · An issue was discovered in Xen 4.14.x.
24Monitor
← EarlierCVE-2020-29568Dec 15, 2020 · An issue was discovered in Xen through 4.14.x.
26Monitor
Later →CVE-2020-29570Dec 15, 2020 · An issue was discovered in Xen through 4.14.x.
24Monitor

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:linux-lts	5.10.4-r0 · Alpine:v3.13	Package registry (OSV)
debian:linux	5.9.15-1 · Debian:12	Package registry (OSV)
debian:linux-4.19	4.19.171-2~deb9u1 · Debian:9	Package registry (OSV)
opensuse:kernel-debug	4.12.14-lp151.28.91.1 · openSUSE:Leap 15.1	Package registry (OSV)
opensuse:kernel-default	4.12.14-lp151.28.91.1 · openSUSE:Leap 15.1	Package registry (OSV)
opensuse:kernel-default-base	5.3.18-lp152.63.1.lp152.8.21.1 · openSUSE:Leap 15.2	Package registry (OSV)
opensuse:kernel-docs	4.12.14-lp151.28.91.1 · openSUSE:Leap 15.1	Package registry (OSV)
opensuse:kernel-kvmsmall	4.12.14-lp151.28.91.1 · openSUSE:Leap 15.1	Package registry (OSV)
opensuse:kernel-obs-build	4.12.14-lp151.28.91.1 · openSUSE:Leap 15.1	Package registry (OSV)
opensuse:kernel-obs-qa	4.12.14-lp151.28.91.1 · openSUSE:Leap 15.1	Package registry (OSV)
opensuse:kernel-preempt	5.3.18-lp152.63.1 · openSUSE:Leap 15.2	Package registry (OSV)
opensuse:kernel-source	4.12.14-lp151.28.91.1 · openSUSE:Leap 15.1	Package registry (OSV)
opensuse:kernel-syms	4.12.14-lp151.28.91.1 · openSUSE:Leap 15.1	Package registry (OSV)
opensuse:kernel-vanilla	4.12.14-lp151.28.91.1 · openSUSE:Leap 15.1	Package registry (OSV)
suse:kernel-azure	5.3.18-18.35.2 · SUSE:Linux Enterprise Module for Public Cloud 15 SP2	Package registry (OSV)
suse:kernel-default	4.12.14-122.60.1 · SUSE:Linux Enterprise High Availability Extension 12 SP5	Package registry (OSV)
suse:kernel-default-base	5.3.18-24.49.2.9.21.2 · SUSE:Linux Enterprise Module for Basesystem 15 SP2	Package registry (OSV)
suse:kernel-docs	4.12.14-122.60.2 · SUSE:Linux Enterprise Software Development Kit 12 SP5	Package registry (OSV)
suse:kernel-livepatch-SLE15-SP2_Update_10	1-5.3.2 · SUSE:Linux Enterprise Live Patching 15 SP2	Package registry (OSV)
suse:kernel-obs-build	4.12.14-122.60.1 · SUSE:Linux Enterprise Software Development Kit 12 SP5	Package registry (OSV)
suse:kernel-preempt	5.3.18-24.49.2 · SUSE:Linux Enterprise Module for Basesystem 15 SP2	Package registry (OSV)
suse:kernel-source	4.12.14-122.60.1 · SUSE:Linux Enterprise Server 12 SP5	Package registry (OSV)
suse:kernel-source-azure	5.3.18-18.35.2 · SUSE:Linux Enterprise Module for Public Cloud 15 SP2	Package registry (OSV)
suse:kernel-syms	4.12.14-122.60.1 · SUSE:Linux Enterprise Server 12 SP5	Package registry (OSV)
suse:kernel-syms-azure	5.3.18-18.35.2 · SUSE:Linux Enterprise Module for Public Cloud 15 SP2	Package registry (OSV)
suse:kgraft-patch-SLE12-SP5_Update_15	1-8.3.1 · SUSE:Linux Enterprise Live Patching 12 SP5	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.

No history yet (it accumulates with the daily EPSS job).

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.

No credits in the CNA record.

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

Impact can extend beyond the vulnerable component (scope changes).

Attack vector: Local
Attack complexity: Low
Privileges required: Low
User interaction: None
Scope: Changed
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:C/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, 10:47 PM UTC

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

References

lists.debian.org/debian-lts-announce/2021/02/msg00018.html

Show all references (5 more)

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

All records