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Fencer Vulns
medium 6.7

CVE-2020-25637 json

A double free memory issue was found to occur in the libvirt API, in versions before 6.8.0, responsible for requesting information about ne…

published 2020-10-06 6 y ago modified 2026-06-17 4 mo ago also EUVD-2020-18305

cvss
6.7
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.5%
EPSS 0.5% chance of exploitation in 30 days, percentile 45%
public exploits
0
none known

Summary

A double free memory issue was found to occur in the libvirt API, in versions before 6.8.0, responsible for requesting information about network interfaces of a running QEMU domain. This flaw affects the polkit access control driver. Specifically, clients connecting to the read-write socket with limited ACL permissions could use this flaw to crash the libvirt daemon, resulting in a denial of service, or potentially escalate their privileges on the system. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability.

Patch / fix

  • redhat libvirt 6.8.0
  • libvirt Debian 14, Debian 13, Debian 12 6.8.0-1

debian advisories DEBIAN-CVE-2020-25637

  • libvirt Ubuntu 18.04 LTS 4.0.0-1ubuntu8.21
  • libvirt Ubuntu 20.04 LTS 6.0.0-0ubuntu8.16

ubuntu advisories UBUNTU-CVE-2020-25637

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 20191022-3.git899d9883.module+el8.3.0+6423+e4cb6418
  • hivex RHEL 8 1.3.18-20.module+el8.3.0+6423+e4cb6418
  • netcf RHEL 8 0.2.8-12.module+el8.1.0+4066+0f1aadab
  • libnbd RHEL 8 1.2.2-1.module+el8.3.0+7353+9de0a3cc
  • nbdkit RHEL 8 1.16.2-4.module+el8.3.0+6922+fd575af8
  • libvirt RHEL 8 6.0.0-35.module+el8.4.0+10230+7a9b21e4
  • nbdfuse RHEL 8 1.2.2-1.module+el8.3.0+7353+9de0a3cc
  • seabios RHEL 8 1.13.0-2.module+el8.3.0+7353+9de0a3cc

red hat advisories RHSA-2021:1762RHSA-2020:5040RHSA-2020:5111

  • libvirt SLES for SAP 12 SP2, SLES 12 SP2-LTSS, SLES 12 SP2-BCL +1 more 2.0.0-27.64.1
  • libvirt SLES for SAP 12 SP3, SLES 12 SP3-LTSS, SLES 12 SP3-BCL +4 more 3.3.0-5.46.1
  • libvirt SLES for SAP 12 SP5, SLES 12 SP5, SLE Software Development Kit 12 SP5 5.1.0-13.19.1
  • libvirt SLES for SAP 12 SP4, SLES 12 SP4-LTSS, OpenStack Cloud Crowbar 9 +1 more 4.0.0-8.23.1
  • libvirt SLE Module for Server Applications 15 SP1, SLE Module for Basesystem 15 SP1 5.1.0-8.24.1
  • libvirt SLE Module for Server Applications 15 SP2, SLE Module for Basesystem 15 SP2 6.0.0-13.8.1
  • libvirt SLES for SAP 15, SLES 15-LTSS, SLE High Performance Computing 15-LTSS +1 more 4.0.0-9.35.1

suse advisories SUSE-SU-2020:3143-1SUSE-SU-2020:3095-1SUSE-SU-2020:3039-1SUSE-SU-2020:3038-1SUSE-SU-2020:3037-1SUSE-SU-2020:2970-1

  • libvirt openSUSE Tumbleweed 7.7.0-2.1
  • libvirt openSUSE Leap 15.1 5.1.0-lp151.7.10.1
  • libvirt openSUSE Leap 15.2 6.0.0-lp152.9.6.2

opensuse advisories openSUSE-SU-2024:11008-1openSUSE-SU-2020:1778-1openSUSE-SU-2020:1777-1

  • hivex AlmaLinux 8 1.3.18-20.module_el8.3.0+2048+e7a0a3ea
  • 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
  • netcf AlmaLinux 8 0.2.8-12.module_el8.3.0+2048+e7a0a3ea
  • libnbd AlmaLinux 8 1.2.2-1.module_el8.5.0+2608+72063365
  • libnbd AlmaLinux 8 1.2.2-1.module_el8.3.0+2048+e7a0a3ea
  • nbdkit AlmaLinux 8 1.16.2-4.module_el8.5.0+2608+72063365
  • nbdfuse AlmaLinux 8 1.2.2-1.module_el8.3.0+2048+e7a0a3ea

almalinux advisories ALSA-2021:1762

  • hivex Rocky Linux 8 1.3.18-20.module+el8.4.0+534+4680a14e
  • 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 6.0.0-35.module+el8.4.0+534+4680a14e
  • seabios Rocky Linux 8 1.13.0-2.module+el8.4.0+534+4680a14e

rocky linux advisories RLSA-2021:1762

  • libvirt Alpine 3.12 6.6.0-r3
  • libvirt Alpine 3.24, Alpine 3.23, Alpine 3.22 +9 more 6.8.0-r0

alpine advisories ALPINE-CVE-2020-25637

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

  • libvirt CBL-Mariner 2.0 6.1.0-4

azure linux advisories AZL-6658

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

  • libvirt Arch Linux 1:7.0.0-1

arch linux advisories AVG-1240

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-2020-25637 updated cvss 6.4

libvirt: double free in qemuAgentGetInterfaces() in qemu_agent.c

  • Red Hat Enterprise Linux 8 Advanced Virtualization libvirt, libvirt-nss, libvirt-libs, libvirt-admin, libvirt-client, libvirt-daemon, +22 more
    affected: no fix available, no fix planned “Will not fix”
  • 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-2020:5111
  • 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, hivex 1.3.18-20.module+el8.3.0+6423+e4cb6418, nbdfuse 1.2.2-1.module+el8.3.0+7353+9de0a3cc, 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, hivex 1.3.18-20.module+el8.3.0+6423+e4cb6418, nbdfuse 1.2.2-1.module+el8.3.0+7353+9de0a3cc, nbdkit 1.16.2-4.module+el8.3.0+6922+fd575af8, seabios 1.13.0-2.module+el8.3.0+7353+9de0a3cc, +88 more
    fixed: vendor fix RHSA-2021:1762
  • Red Hat Enterprise Linux Client (v. 7) libvirt 4.5.0-36.el7_9.3, libvirt-libs 4.5.0-36.el7_9.3, libvirt-client 4.5.0-36.el7_9.3, libvirt-daemon 4.5.0-36.el7_9.3, libvirt-daemon-kvm 4.5.0-36.el7_9.3, libvirt-bash-completion 4.5.0-36.el7_9.3, +18 more Red Hat Enterprise Linux Client Optional (v. 7) libvirt-nss 4.5.0-36.el7_9.3, libvirt-admin 4.5.0-36.el7_9.3, libvirt-daemon-lxc 4.5.0-36.el7_9.3, libvirt-login-shell 4.5.0-36.el7_9.3, libvirt-lock-sanlock 4.5.0-36.el7_9.3 Red Hat Enterprise Linux ComputeNode Optional (v. 7) libvirt 4.5.0-36.el7_9.3, libvirt-nss 4.5.0-36.el7_9.3, libvirt-admin 4.5.0-36.el7_9.3, libvirt-daemon 4.5.0-36.el7_9.3, libvirt-daemon-kvm 4.5.0-36.el7_9.3, libvirt-daemon-lxc 4.5.0-36.el7_9.3, +20 more Red Hat Enterprise Linux Server (v. 7) libvirt 4.5.0-36.el7_9.3, libvirt-libs 4.5.0-36.el7_9.3, libvirt-client 4.5.0-36.el7_9.3, libvirt-daemon 4.5.0-36.el7_9.3, libvirt-daemon-kvm 4.5.0-36.el7_9.3, libvirt-bash-completion 4.5.0-36.el7_9.3, +18 more Red Hat Enterprise Linux Server Optional (v. 7) libvirt-nss 4.5.0-36.el7_9.3, libvirt-admin 4.5.0-36.el7_9.3, libvirt-daemon-lxc 4.5.0-36.el7_9.3, libvirt-login-shell 4.5.0-36.el7_9.3, libvirt-lock-sanlock 4.5.0-36.el7_9.3 Red Hat Enterprise Linux Workstation (v. 7) libvirt 4.5.0-36.el7_9.3, libvirt-libs 4.5.0-36.el7_9.3, libvirt-client 4.5.0-36.el7_9.3, libvirt-daemon 4.5.0-36.el7_9.3, libvirt-daemon-kvm 4.5.0-36.el7_9.3, libvirt-bash-completion 4.5.0-36.el7_9.3, +18 more
    +1 more products
    Red Hat Enterprise Linux Workstation Optional (v. 7) libvirt-nss 4.5.0-36.el7_9.3, libvirt-admin 4.5.0-36.el7_9.3, libvirt-daemon-lxc 4.5.0-36.el7_9.3, libvirt-login-shell 4.5.0-36.el7_9.3, libvirt-lock-sanlock 4.5.0-36.el7_9.3
    fixed: vendor fix RHSA-2020:5040
  • Red Hat Enterprise Linux 5 libvirt 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

0.53% chance of exploitation in the next 30 days, higher than 45% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
NVD 3.1 6.7 CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
NVD 2.0 7.2 AV:L/AC:L/Au:N/C:C/I:C/A:C

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.