CVE-2021-4145

mediumpriority · track · 26EPSS 0.004 · 33 %ileDEEUUS

grimoire priorityP3 · Track

Exploitable?

—

no known exploitation

Likely / severe?

0.39% (33rd) EPSS

CVSS 4.9 · medium

Is it mine?

11 products

Check your exposure

Who says so?

4 sources

cnnvd · enisa_euvd · cert_bund · nvd

EPSS · scored 2026-10-27

A NULL pointer dereference issue was found in the block mirror layer of QEMU in versions prior to 6.2.0. The `self` pointer is dereferenced in mirror_wait_on_conflicts() without ensuring that it's not NULL. A malicious unprivileged user within the guest could use this flaw to crash the QEMU process on the host when writing data reaches the threshold of mirroring node.

cvss

Technical severity, 0–10. One row per scoring source.

6.5

010

base score 0–10 · higher = more severe · hover a vector to decode

v2.04.9mediumAV:L/AC:L/Au:N/C:N/I:N/A:Cprimary · NVD / NIST USexploitability 3.9 · impact 6.9

v3.16.5mediumCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:Hprimary · NVD / NIST USexploitability 2 · impact 4

v3.16mediumCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H/E:Usecondary · CVSS-BT (t0sche)

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-476USprimary

affected products (11)

Products and version ranges known to be affected.

Avaya Aura Application Enablement Servicesall versionscert_bundDEcpe:/a:avaya:aura_application_enablement_services:-
Avaya Aura Communication Managerall versionscert_bundDEcpe:/a:avaya:communication_manager:-
Broadcom Brocade Switchall versionscert_bundDEcpe:/h:brocade:switch:-
Gentoo Linuxall versionscert_bundDEcpe:/o:gentoo:linux:-
HPE Switchall versionscert_bundDEcpe:/h:hp:switch:-
Open Source QEMUall versionscert_bundDEcpe:/a:qemu:qemu:-
Oracle Linuxall versionscert_bundDEcpe:/o:oracle:linux:-
Red Hat Enterprise Linuxall versionscert_bundDEcpe:/o:redhat:enterprise_linux:-
n/a qemu≤ qemu-kvm 6.2.0enisa_euvdEU
qemu qemu= 6.1.0nvdUScpe:2.3:a:qemu:qemu:*:*:*:*:*:*:*:*
redhat enterprise linux= 8.0nvdUScpe:2.3:o:redhat:enterprise_linux:*:*:*:*:*:*:*:*

advisories (2)

Vendor and ecosystem advisories describing this.

WID-SEC-W-2022-1125QEMU: Schwachstelle ermöglicht Denial of ServiceDeutsch2021-12-21csaf · cert_bundDE
Ein lokaler Angreifer kann eine Schwachstelle in QEMU ausnutzen, um einen Denial of Service Angriff durchzuführen.
WID-SEC-W-2023-1969HPE Fabric OS: Mehrere Schwachstellen ermöglichen PrivilegieneskalationDeutsch2023-08-06csaf · cert_bundDE
Ein entfernter, anonymer Angreifer kann mehrere Schwachstellen in HPE Fabric OS für HPE Fibre Channel und SAN Switches ausnutzen, um seine Privilegien zu erhöhen, Informationen offenzulegen oder einen Denial of Service Zustand herbeizuführen.

also known as (3)

Other names and identifiers for this entity.

sources

Which sources assert this record, and when.

cnnvd enisa_euvd cert_bund nvd NVD CVE.org MITRE

published 2022-01-25modified 2026-06-17

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+8781 more

references (15)

External citations — patches, advisories, analysis.

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