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Fencer Vulns
medium 6.5

CVE-2021-3667 json

An improper locking issue was found in the virStoragePoolLookupByTargetPath API of libvirt.

published 2022-03-02 4 y ago modified 2026-06-17 4 mo ago also EUVD-2021-26959

cvss
6.5
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
1.4%
EPSS 1.4% chance of exploitation in 30 days, percentile 72%
public exploits
0
none known

Summary

An improper locking issue was found in the virStoragePoolLookupByTargetPath API of libvirt. It occurs in the storagePoolLookupByTargetPath function where a locked virStoragePoolObj object is not properly released on ACL permission failure. Clients connecting to the read-write socket with limited ACL permissions could use this flaw to acquire the lock and prevent other users from accessing storage pool/volume APIs, resulting in a denial of service condition. The highest threat from this vulnerability is to system availability.

Patch / fix

  • libvirt Debian 14, Debian 13, Debian 12 7.6.0-1

debian advisories DEBIAN-CVE-2021-3667

  • libvirt Ubuntu 20.04 LTS 6.0.0-0ubuntu8.16
  • libvirt Ubuntu 22.04 LTS 7.6.0-0ubuntu3

ubuntu advisories UBUNTU-CVE-2021-3667

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 advanced virtualization 8.4 20200717-1.gite18ddad8.module+el8.4.0+8855+a9e237a9
  • hivex advanced virtualization 8.4 1.3.18-21.module+el8.4.0+11609+2eba841a
  • netcf advanced virtualization 8.4 0.2.8-12.module+el8.4.0+8855+a9e237a9
  • swtpm advanced virtualization 8.4 0.4.2-1.20201201git2df14e3.module+el8.4.0+9341+96cf2672
  • libnbd advanced virtualization 8.4 1.6.0-3.module+el8.4.0+9856+bbc47853
  • nbdkit advanced virtualization 8.4 1.24.0-1.module+el8.4.0+9341+96cf2672
  • libtpms advanced virtualization 8.4 0.7.4-4.20201106git2452a24dab.module+el8.4.0+10596+32ba7df3
  • libvirt advanced virtualization 8.4 7.0.0-14.4.module+el8.4.0+12413+d23780e6

red hat advisories RHSA-2021:3703RHSA-2021:3704RHSA-2021:4191

  • libvirt SLE Module for Server Applications 15 SP2, SLE Module for Basesystem 15 SP2, SLE Micro 5.0 6.0.0-13.21.1
  • libvirt SLES for SAP 15 SP1, SLES 15 SP1-LTSS, SLES 15 SP1-BCL +3 more 5.1.0-8.29.1
  • libvirt SLES for SAP 12 SP5, SLES 12 SP5, SLE Software Development Kit 12 SP5 5.1.0-13.25.1
  • libvirt SLE Module for Server Applications 15 SP3, SLE Module for Basesystem 15 SP3 7.1.0-6.5.1

suse advisories SUSE-SU-2021:3586-1SUSE-SU-2021:3540-1SUSE-SU-2021:3277-1SUSE-SU-2021:2812-1

  • libvirt openSUSE Tumbleweed 7.7.0-2.1
  • libvirt openSUSE Leap 15.2 6.0.0-lp152.9.15.1
  • libvirt openSUSE Leap 15.3 7.1.0-6.5.1

opensuse advisories openSUSE-SU-2024:11008-1openSUSE-SU-2021:1451-1openSUSE-SU-2021:2812-1

  • hivex AlmaLinux 8 1.3.18-21.module_el8.5.0+2608+72063365
  • netcf AlmaLinux 8 0.2.8-12.module_el8.5.0+2608+72063365
  • netcf AlmaLinux 8 0.2.8-12.module_el8.6.0+2880+7d9e3703
  • libnbd AlmaLinux 8 1.2.2-1.module_el8.5.0+2608+72063365
  • nbdkit AlmaLinux 8 1.16.2-4.module_el8.5.0+2608+72063365
  • libvirt AlmaLinux 8 6.0.0-37.module_el8.5.0+2608+72063365
  • nbdfuse AlmaLinux 8 1.2.2-1.module_el8.5.0+2608+72063365
  • seabios AlmaLinux 8 1.13.0-2.module_el8.5.0+2608+72063365

almalinux advisories ALSA-2021:4191

  • hivex Rocky Linux 8 1.3.18-21.module+el8.4.0+642+7e26f5e1
  • hivex Rocky Linux 8 1.3.18-21.module+el8.5.0+670+c4aa478c
  • 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
  • libnbd Rocky Linux 8 1.2.2-1.module+el8.4.0+534+4680a14e
  • nbdkit Rocky Linux 8 1.16.2-4.module+el8.4.0+534+4680a14e
  • libvirt Rocky Linux 8 6.0.0-37.module+el8.5.0+670+c4aa478c

rocky linux advisories RLSA-2021:4191

  • libvirt Arch Linux 1:7.6.0-1

arch linux advisories AVG-2230

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-2021-3667 updated cvss 6.5

libvirt: Improper locking on ACL failure in virStoragePoolLookupByTargetPath API

  • Red Hat Enterprise Linux 7 libvirt, libvirt-nss, libvirt-libs, libvirt-admin, libvirt-client, libvirt-daemon, +24 more
    affected: workaround, no fix planned “Out of support scope”
  • Red Hat Enterprise Linux 8 Advanced Virtualization libvirt, libvirt-nss, libvirt-libs, libvirt-admin, libvirt-client, libvirt-daemon, +22 more
    affected: workaround, no fix available “Fix deferred”
  • Red Hat Advanced Virtualization CodeReady Builder for RHEL 8.2.1 libnbd 1.2.2-1.module+el8.2.0+5644+32ac38d4, netcf 0.2.8-12.module+el8.2.0+4793+b09dd2fb, hivex 1.3.18-20.module+el8.2.0+5588+63a201c3, nbdfuse 1.2.2-1.module+el8.2.0+5644+32ac38d4, seabios 1.13.0-2.module+el8.2.1+7284+aa32a2c4, libiscsi 1.18.0-8.module+el8.2.0+4793+b09dd2fb, +45 more Red Hat Advanced Virtualization for RHEL 8.2.1 libnbd 1.2.2-1.module+el8.2.0+5644+32ac38d4, netcf 0.2.8-12.module+el8.2.0+4793+b09dd2fb, hivex 1.3.18-20.module+el8.2.0+5588+63a201c3, nbdfuse 1.2.2-1.module+el8.2.0+5644+32ac38d4, nbdkit 1.16.2-4.module+el8.2.1+6710+effcb1df, seabios 1.13.0-2.module+el8.2.1+7284+aa32a2c4, +96 more
    fixed: vendor fix RHSA-2021:3704
  • Red Hat Advanced Virtualization for RHEL 8.4.0.Z libnbd 1.6.0-3.module+el8.4.0+9856+bbc47853, netcf 0.2.8-12.module+el8.4.0+8855+a9e237a9, nbdfuse 1.6.0-3.module+el8.4.0+9856+bbc47853, nbdkit 1.24.0-1.module+el8.4.0+9341+96cf2672, hivex 1.3.18-21.module+el8.4.0+11609+2eba841a, seabios 1.14.0-1.module+el8.4.0+8855+a9e237a9, +110 more
    fixed: vendor fix RHSA-2021:3703
  • Red Hat CodeReady Linux Builder (v. 8) libnbd 1.2.2-1.module+el8.3.0+7353+9de0a3cc, netcf 0.2.8-12.module+el8.1.0+4066+0f1aadab, nbdfuse 1.2.2-1.module+el8.3.0+7353+9de0a3cc, hivex 1.3.18-21.module+el8.5.0+10709+b3edb581, seabios 1.13.0-2.module+el8.3.0+7353+9de0a3cc, libiscsi 1.18.0-8.module+el8.1.0+4066+0f1aadab, +39 more Red Hat Enterprise Linux AppStream (v. 8) libnbd 1.2.2-1.module+el8.3.0+7353+9de0a3cc, netcf 0.2.8-12.module+el8.1.0+4066+0f1aadab, nbdfuse 1.2.2-1.module+el8.3.0+7353+9de0a3cc, nbdkit 1.16.2-4.module+el8.3.0+6922+fd575af8, hivex 1.3.18-21.module+el8.5.0+10709+b3edb581, seabios 1.13.0-2.module+el8.3.0+7353+9de0a3cc, +88 more
    fixed: vendor fix RHSA-2021:4191
  • Red Hat Enterprise Linux 6 libvirt, libvirt-client, libvirt-python, libvirt-lock-sanlock Red Hat Enterprise Linux 9 libvirt, libvirt-nss, libvirt-libs, libvirt-client, libvirt-daemon, libvirt-ssh-proxy, +25 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

1.37% chance of exploitation in the next 30 days, higher than 72% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
NVD 3.1 6.5 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
NVD 2.0 3.5 AV:N/AC:M/Au:S/C:N/I:N/A:P

Affected products

  • n/a libvirt

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.