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NVD / CVE Program· CNA mitre

CVE-2020-25604: An issue was discovered in Xen through 4.14.x.

Noroxi assessment

Priority: Monitor (action score 18/100)

  • 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: 0.26% (FIRST EPSS).
  • Someone with local access to the system can trigger it. A low-privileged account is enough. No user action is required. Special conditions such as timing or configuration are required.
  • Fixed version: xen (Alpine:v3.10) 4.12.3-r4; xen (Alpine:v3.11) 4.13.1-r4; xen (Alpine:v3.13) 4.14.0-r1.
  • Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Upgrade to xen (Alpine:v3.10) 4.12.3-r4; xen (Alpine:v3.11) 4.13.1-r4; xen (Alpine:v3.13) 4.14.0-r1 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 Xen through 4.14.x. There is a race condition when migrating timers between x86 HVM vCPUs. When migrating timers of x86 HVM guests between its vCPUs, the locking model used allows for a second vCPU of the same guest (also operating on the timers) to release a lock that it didn't acquire. The most likely effect of the issue is a hang or crash of the hypervisor, i.e., a Denial of Service (DoS). All versions of Xen are affected. Only x86 systems are vulnerable. Arm systems are not vulnerable. Only x86 HVM guests can leverage the vulnerability. x86 PV and PVH cannot leverage the vulnerability. Only guests with more than one vCPU can exploit the vulnerability.

MediumCVSS 4.7 · v3.1—No exploit Fix available
Published
Sep 23, 2020
Updated
Jun 16, 2026
EPSS
0.2% · 17th percentile

Report tools

JSON

Action score

18

Monitor

Low priority for now.

CVSS
18 / 40 · 4.7 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.2%

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

If any of these changes, we'll tell you in the daily email digest.

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When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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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.

VendorProduct
xenxen
fedoraprojectfedora
debiandebian linux
opensuseleap

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
  • fedoraproject fedora31
  • fedoraproject fedora32
  • fedoraproject fedora33
  • opensuse leap15.2
  • xen xenup to 4.14.0 inclusive

Package-level exposure

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

EcosystemPackageAffected rangeFix
Alpine:v3.10xenbefore 4.12.3-r44.12.3-r4
Alpine:v3.11xenbefore 4.13.1-r44.13.1-r4
Alpine:v3.13xenbefore 4.14.0-r14.14.0-r1
Alpine:v3.9xenbefore 4.11.4-r24.11.4-r2
Debian:10xenbefore 4.11.4+37-g3263f257ca-14.11.4+37-g3263f257ca-1
Debian:12xenbefore 4.14.0+80-gd101b417b7-14.14.0+80-gd101b417b7-1
openSUSE:Leap 15.2xenbefore 4.13.1_08-lp152.2.9.14.13.1_08-lp152.2.9.1
SUSE:HPE Helion OpenStack 8xenbefore 4.9.4_12-3.74.14.9.4_12-3.74.1
SUSE:Linux Enterprise High Performance Computing 15-ESPOSxenbefore 4.10.4_16-3.41.14.10.4_16-3.41.1
SUSE:Linux Enterprise Module for Basesystem 15 SP1xenbefore 4.12.3_08-3.28.14.12.3_08-3.28.1
SUSE:Linux Enterprise Module for Basesystem 15 SP2xenbefore 4.13.1_08-3.10.14.13.1_08-3.10.1
SUSE:Linux Enterprise Server 11 SP4-LTSSxenbefore 4.4.4_44-61.55.14.4.4_44-61.55.1
SUSE:Linux Enterprise Software Development Kit 12 SP5xenbefore 4.12.3_08-3.24.14.12.3_08-3.24.1
SUSE:OpenStack Cloud 7xenbefore 4.7.6_10-43.67.14.7.6_10-43.67.1
SUSE:OpenStack Cloud 9xenbefore 4.11.4_08-2.36.14.11.4_08-2.36.1

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-2020-25602Sep 23, 2020 · An issue was discovered in Xen through 4.14.x.
    24Monitor
  • ← EarlierCVE-2020-25603Sep 23, 2020 · An issue was discovered in Xen through 4.14.x.
    31Monitor
  • Later →CVE-2020-27670Oct 22, 2020 · An issue was discovered in Xen through 4.14.x allowing x86 guest OS users to cause a denial of service (data corruption), cause a data leak,
    31Monitor

Remediation

Which version to upgrade to

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

Product / packageFixed versionSource
alpine:xen4.12.3-r4 · Alpine:v3.10Package registry (OSV)
debian:xen4.14.0+80-gd101b417b7-1 · Debian:12Package registry (OSV)
opensuse:xen4.13.1_08-lp152.2.9.1 · openSUSE:Leap 15.2Package registry (OSV)
suse:xen4.4.4_44-61.55.1 · SUSE:Linux Enterprise Server 11 SP4-LTSSPackage 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).

National notice (Türkiye Cybersecurity Directorate / USOM)

Official security notices citing this record; remediation advice is on the agency's page.

All national notices →

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.
  • Special conditions such as timing or configuration are required.

If successful

Confidentiality
none
Integrity
none
Availability
high · the service can be disrupted
Attack vector
Local
Attack complexity
High
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality impact
None
Integrity impact
None
Availability impact
High

Weakness class (CWE)

CWE-362 · Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')

CVSS vector

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

nvd-primary

Attack context

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

ATT&CK techniques

—

Change log

  1. Fix✗ → ✓

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

References

Show all references (6 more)

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

All records