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NVD / CVE Program· CNA redhat

CVE-2021-4158: A NULL pointer dereference issue was found in the ACPI code of QEMU.

Noroxi assessment

Priority: Monitor (action score 24/100)

  • 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. Administrator privileges are required. No user action is required. No special conditions are required; it is repeatable.
  • Fixed version: qemu-guest-agent (AlmaLinux:9) 17:7.0.0-13.el9; qemu-img (AlmaLinux:9) 17:7.0.0-13.el9; qemu-kvm (AlmaLinux:9) 17:7.0.0-13.el9.
  • Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Upgrade to qemu-guest-agent (AlmaLinux:9) 17:7.0.0-13.el9; qemu-img (AlmaLinux:9) 17:7.0.0-13.el9; qemu-kvm (AlmaLinux:9) 17:7.0.0-13.el9 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

A NULL pointer dereference issue was found in the ACPI code of QEMU. A malicious, privileged user within the guest could use this flaw to crash the QEMU process on the host, resulting in a denial of service condition.

MediumCVSS 6.0 · v3.1—No exploit Fix available
Published
Aug 24, 2022
Updated
Jun 17, 2026
EPSS
0.3% · 34th percentile

Report tools

JSON

Action score

24

Monitor

Low priority for now.

CVSS
24 / 40 · 6.0 / 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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  • when exploit code appears or is weaponized
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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
qemuqemu
redhatenterprise linux

Affected versions

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

  • qemu qemu6.0.0 and later · before 7.0.0
  • redhat enterprise linux9.0

Versions reported by the vendor

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

  • n/a QEMU

    • Affects v6.0.0 and above.affected

Package-level exposure

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

EcosystemPackageAffected rangeFix
AlmaLinux:9qemu-guest-agentbefore 17:7.0.0-13.el917:7.0.0-13.el9
AlmaLinux:9qemu-imgbefore 17:7.0.0-13.el917:7.0.0-13.el9
AlmaLinux:9qemu-kvmbefore 17:7.0.0-13.el917:7.0.0-13.el9
AlmaLinux:9qemu-kvm-audio-pabefore 17:7.0.0-13.el917:7.0.0-13.el9
AlmaLinux:9qemu-kvm-block-curlbefore 17:7.0.0-13.el917:7.0.0-13.el9
AlmaLinux:9qemu-kvm-block-rbdbefore 17:7.0.0-13.el917:7.0.0-13.el9
AlmaLinux:9qemu-kvm-commonbefore 17:7.0.0-13.el917:7.0.0-13.el9
AlmaLinux:9qemu-kvm-corebefore 17:7.0.0-13.el917:7.0.0-13.el9
AlmaLinux:9qemu-kvm-device-display-virtio-gpubefore 17:7.0.0-13.el917:7.0.0-13.el9
AlmaLinux:9qemu-kvm-device-display-virtio-gpu-ccwbefore 17:7.0.0-13.el917:7.0.0-13.el9
AlmaLinux:9qemu-kvm-device-display-virtio-gpu-glbefore 17:7.0.0-13.el917:7.0.0-13.el9
AlmaLinux:9qemu-kvm-device-display-virtio-gpu-pcibefore 17:7.0.0-13.el917:7.0.0-13.el9
AlmaLinux:9qemu-kvm-device-display-virtio-gpu-pci-glbefore 17:7.0.0-13.el917:7.0.0-13.el9
AlmaLinux:9qemu-kvm-device-display-virtio-vgabefore 17:7.0.0-13.el917:7.0.0-13.el9
AlmaLinux:9qemu-kvm-device-display-virtio-vga-glbefore 17:7.0.0-13.el917:7.0.0-13.el9
AlmaLinux:9qemu-kvm-device-usb-hostbefore 17:7.0.0-13.el917:7.0.0-13.el9
AlmaLinux:9qemu-kvm-device-usb-redirectbefore 17:7.0.0-13.el917:7.0.0-13.el9
AlmaLinux:9qemu-kvm-docsbefore 17:7.0.0-13.el917:7.0.0-13.el9
AlmaLinux:9qemu-kvm-toolsbefore 17:7.0.0-13.el917:7.0.0-13.el9
AlmaLinux:9qemu-kvm-ui-egl-headlessbefore 17:7.0.0-13.el917:7.0.0-13.el9
AlmaLinux:9qemu-kvm-ui-openglbefore 17:7.0.0-13.el917:7.0.0-13.el9
AlmaLinux:9qemu-pr-helperbefore 17:7.0.0-13.el917:7.0.0-13.el9
Debian:12qemubefore 1:6.2+dfsg-21:6.2+dfsg-2
openSUSE:Tumbleweedqemubefore 6.2.0-40.16.2.0-40.1

+46

Same product

qemu: all records

Other highest-scoring records for the same primary product.

  • CVE-2019-12928The QMP migrate command in QEMU version 4.0.0 and earlier is vulnerable to OS command injection, which allows the remote attacker to achieve
    60This week
  • CVE-2015-8556Local privilege escalation vulnerability in the Gentoo QEMU package before 2.5.0-r1.
    44Plan
  • CVE-2017-15118A stack-based buffer overflow vulnerability was found in NBD server implementation in qemu before 2.11 allowing a client to request an expor
    43Plan

Published before and after this one in the same product

  • ← EarlierCVE-2022-35414Jul 10, 2022 · softmmu/physmem.c in QEMU through 7.0.0 can perform an uninitialized read on the translate_fail path, leading to an io_readx or io_writex cr
    35Monitor
  • ← EarlierCVE-2020-14394Aug 17, 2022 · An infinite loop flaw was found in the USB xHCI controller emulation of QEMU while computing the length of the Transfer Request Block (TRB)
    12Monitor
  • Later →CVE-2021-3929Aug 25, 2022 · A DMA reentrancy issue was found in the NVM Express Controller (NVME) emulation in QEMU.
    32Monitor

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
almalinux:qemu-guest-agent17:7.0.0-13.el9 · AlmaLinux:9Package registry (OSV)
almalinux:qemu-img17:7.0.0-13.el9 · AlmaLinux:9Package registry (OSV)
almalinux:qemu-kvm17:7.0.0-13.el9 · AlmaLinux:9Package registry (OSV)
almalinux:qemu-kvm-audio-pa17:7.0.0-13.el9 · AlmaLinux:9Package registry (OSV)
almalinux:qemu-kvm-block-curl17:7.0.0-13.el9 · AlmaLinux:9Package registry (OSV)
almalinux:qemu-kvm-block-rbd17:7.0.0-13.el9 · AlmaLinux:9Package registry (OSV)
almalinux:qemu-kvm-common17:7.0.0-13.el9 · AlmaLinux:9Package registry (OSV)
almalinux:qemu-kvm-core17:7.0.0-13.el9 · AlmaLinux:9Package registry (OSV)
almalinux:qemu-kvm-device-display-virtio-gpu17:7.0.0-13.el9 · AlmaLinux:9Package registry (OSV)
almalinux:qemu-kvm-device-display-virtio-gpu-ccw17:7.0.0-13.el9 · AlmaLinux:9Package registry (OSV)
almalinux:qemu-kvm-device-display-virtio-gpu-gl17:7.0.0-13.el9 · AlmaLinux:9Package registry (OSV)
almalinux:qemu-kvm-device-display-virtio-gpu-pci17:7.0.0-13.el9 · AlmaLinux:9Package registry (OSV)
debian:qemu1:6.2+dfsg-2 · Debian:12Package registry (OSV)
opensuse:qemu6.2.0-40.1 · openSUSE:TumbleweedPackage registry (OSV)
red hat:qemu-guest-agent17:7.0.0-13.el9 · Red Hat:enterprise_linux:9::appstreamPackage registry (OSV)
red hat:qemu-guest-agent-debuginfo17:7.0.0-13.el9 · Red Hat:enterprise_linux:9::appstreamPackage registry (OSV)
red hat:qemu-img17:7.0.0-13.el9 · Red Hat:enterprise_linux:9::appstreamPackage registry (OSV)
red hat:qemu-img-debuginfo17:7.0.0-13.el9 · Red Hat:enterprise_linux:9::appstreamPackage registry (OSV)
red hat:qemu-kvm17:7.0.0-13.el9 · Red Hat:enterprise_linux:9::appstreamPackage registry (OSV)
red hat:qemu-kvm-audio-pa17:7.0.0-13.el9 · Red Hat:enterprise_linux:9::appstreamPackage registry (OSV)
red hat:qemu-kvm-audio-pa-debuginfo17:7.0.0-13.el9 · Red Hat:enterprise_linux:9::appstreamPackage registry (OSV)
red hat:qemu-kvm-block-curl17:7.0.0-13.el9 · Red Hat:enterprise_linux:9::appstreamPackage registry (OSV)
red hat:qemu-kvm-block-curl-debuginfo17:7.0.0-13.el9 · Red Hat:enterprise_linux:9::appstreamPackage registry (OSV)
red hat:qemu-kvm-block-rbd17:7.0.0-13.el9 · Red Hat:enterprise_linux:9::appstreamPackage registry (OSV)
red hat:qemu-kvm-block-rbd-debuginfo17:7.0.0-13.el9 · Red Hat:enterprise_linux:9::appstreamPackage registry (OSV)
red hat:qemu-kvm-common17:7.0.0-13.el9 · Red Hat:enterprise_linux:9::appstreamPackage registry (OSV)
rocky linux:qemu-kvm7:7.0.0-13.el9 · Rocky Linux:9Package 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.

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.
  • Administrator privileges are required.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
none
Integrity
none
Availability
high · the service can be disrupted

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

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

Weakness class (CWE)

CWE-476 · NULL Pointer Dereference

CVSS vector

CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/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.

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

Change log

  1. Fix✗ → ✓

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

References

Show all references (3 more)

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

All records