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Fencer Vulns
medium 6.0

CVE-2021-4158 json

A NULL pointer dereference issue was found in the ACPI code of QEMU.

published 2022-08-24 4 y ago modified 2026-06-17 4 mo ago also EUVD-2021-34026

cvss
6.0
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.4%
EPSS 0.4% chance of exploitation in 30 days, percentile 34%
public exploits
0
none known

Summary

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.

Patch / fix

  • qemu qemu 7.0.0
  • qemu Debian 14, Debian 13, Debian 12 1:6.2+dfsg-2

debian advisories DEBIAN-CVE-2021-4158

  • qemu Ubuntu 22.04 LTS 1:6.2+dfsg-2ubuntu5

ubuntu advisories UBUNTU-CVE-2021-4158

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • SLOF RHEL 8 20210217-1.module+el8.6.0+14480+c0a3aa0f
  • hivex RHEL 8 1.3.18-23.module+el8.6.0+14480+c0a3aa0f
  • netcf RHEL 8 0.2.8-12.module+el8.6.0+14480+c0a3aa0f
  • swtpm RHEL 8 0.7.0-1.20211109gitb79fd91.module+el8.6.0+14480+c0a3aa0f
  • libnbd RHEL 8 1.6.0-5.module+el8.6.0+14480+c0a3aa0f
  • nbdkit RHEL 8 1.24.0-4.module+el8.6.0+14480+c0a3aa0f
  • libtpms RHEL 8 0.9.1-0.20211126git1ff6fe1f43.module+el8.6.0+14480+c0a3aa0f
  • libvirt RHEL 8 8.0.0-5.module+el8.6.0+14480+c0a3aa0f

red hat advisories RHSA-2022:1759RHSA-2022:7967

  • qemu openSUSE Tumbleweed 6.2.0-40.1

opensuse advisories openSUSE-SU-2024:11862-1

  • qemu-kvm AlmaLinux 9 17:7.0.0-13.el9
  • qemu-img AlmaLinux 9 17:7.0.0-13.el9
  • qemu-kvm-core AlmaLinux 9 17:7.0.0-13.el9
  • qemu-kvm-tools AlmaLinux 9 17:7.0.0-13.el9
  • qemu-pr-helper AlmaLinux 9 17:7.0.0-13.el9
  • qemu-kvm-common AlmaLinux 9 17:7.0.0-13.el9
  • qemu-guest-agent AlmaLinux 9 17:7.0.0-13.el9
  • qemu-kvm-audio-pa AlmaLinux 9 17:7.0.0-13.el9

almalinux advisories ALSA-2022:7967ALSA-2022:1759

  • qemu-kvm Rocky Linux 9 7:7.0.0-13.el9
  • hivex Rocky Linux 8 1.3.18-23.module+el8.7.0+1084+97b81f61
  • hivex Rocky Linux 8 1.3.18-23.module+el8.6.0+847+b490afdd
  • netcf Rocky Linux 8 0.2.8-12.module+el8.7.0+1084+97b81f61
  • netcf Rocky Linux 8 0.2.8-12.module+el8.4.0+534+4680a14e
  • netcf Rocky Linux 8 0.2.8-12.module+el8.6.0+847+b490afdd
  • swtpm Rocky Linux 8 0.7.0-1.20211109gitb79fd91.module+el8.6.0+847+b490afdd
  • libnbd Rocky Linux 8 1.6.0-5.module+el8.7.0+1084+97b81f61

rocky linux advisories RLSA-2022:7967RLSA-2022:1759

  • qemu Alpine 3.24, Alpine 3.23, Alpine 3.22 +5 more 7.0.0-r0

alpine advisories ALPINE-CVE-2021-4158

Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • qemu CBL-Mariner 2.0 6.2.0-7
  • qemu Azure Linux 3.0 6.2.0-18

azure linux advisories AZL-10679AZL-35153

Azure Linux vulnerability data, Copyright (c) Microsoft Corporation, from https://github.com/microsoft/AzureLinuxVulnerabilityData via OSV, under the MIT licence; changed: normalised to fixed package versions per release. MIT

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2021-4158 updated cvss 6.0

QEMU: NULL pointer dereference in pci_write() in hw/acpi/pcihp.c

  • Red Hat Enterprise Linux 8 Advanced Virtualization qemu-img, qemu-kvm, qemu-kiwi, qemu-kvm-core, qemu-kvm-tests, qemu-kvm-common, +9 more
    affected: workaround, no fix available “Fix deferred”
  • Red Hat OpenStack Platform 10 (Newton) qemu-img-rhev, qemu-kvm-rhev, qemu-kvm-tools-rhev, qemu-kvm-common-rhev Red Hat OpenStack Platform 13 (Queens) qemu-img-rhev, qemu-kvm-rhev, qemu-kvm-tools-rhev, qemu-kvm-common-rhev
    affected: workaround, no fix planned “Out of support scope”
  • Red Hat Enterprise Linux AppStream (v. 8) libnbd 1.6.0-5.module+el8.6.0+14480+c0a3aa0f, netcf 0.2.8-12.module+el8.6.0+14480+c0a3aa0f, hivex 1.3.18-23.module+el8.6.0+14480+c0a3aa0f, libvirt 8.0.0-5.module+el8.6.0+14480+c0a3aa0f, nbdfuse 1.6.0-5.module+el8.6.0+14480+c0a3aa0f, nbdkit 1.24.0-4.module+el8.6.0+14480+c0a3aa0f, +104 more
    fixed: vendor fix RHSA-2022:1759
  • Red Hat Enterprise Linux AppStream (v. 9) qemu-img 7.0.0-13.el9, qemu-kvm 7.0.0-13.el9, qemu-kvm-core 7.0.0-13.el9, qemu-kvm-tools 7.0.0-13.el9, qemu-pr-helper 7.0.0-13.el9, qemu-kvm-common 7.0.0-13.el9, +15 more
    fixed: vendor fix RHSA-2022:7967
  • Red Hat Enterprise Linux CRB (v. 8) libnbd 1.6.0-5.module+el8.6.0+14480+c0a3aa0f, netcf 0.2.8-12.module+el8.6.0+14480+c0a3aa0f, hivex 1.3.18-23.module+el8.6.0+14480+c0a3aa0f, libvirt 8.0.0-5.module+el8.6.0+14480+c0a3aa0f, nbdfuse 1.6.0-5.module+el8.6.0+14480+c0a3aa0f, SLOF 20210217-1.module+el8.6.0+14480+c0a3aa0f, +38 more
    fixed: vendor fix RHSA-2022:1759
  • Red Hat Enterprise Linux 6 qemu-img, qemu-kvm, qemu-kvm-tools, qemu-guest-agent, qemu-guest-agent-win32 Red Hat Enterprise Linux 7 qemu-img, qemu-kvm, libcacard, qemu-img-ma, qemu-kvm-ma, qemu-kvm-tools, +5 more Red Hat Enterprise Linux 8 Advanced Virtualization qemu-img, qemu-kvm, qemu-kiwi, qemu-kvm-core, qemu-kvm-tests, qemu-kvm-common, +9 more
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

0.40% chance of exploitation in the next 30 days, higher than 34% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • gitlab.com https://gitlab.com/qemu-project/qemu/-/issues/770 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
NVD 3.1 6.0 CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:N/I:N/A:H

Affected products

  • n/a QEMU

Classification

Weakness

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.