Linux Distros Unpatched Vulnerability : CVE-2021-3975

medium Nessus Plugin ID 224112

Synopsis

The Linux/Unix host has one or more packages installed with a vulnerability that the vendor indicates will not be patched.

Description

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

- A use-after-free flaw was found in libvirt. The qemuMonitorUnregister() function in qemuProcessHandleMonitorEOF is called using multiple threads without being adequately protected by a monitor lock. This flaw could be triggered by the virConnectGetAllDomainStats API when the guest is shutting down. An unprivileged client with a read-only connection could use this flaw to perform a denial of service attack by causing the libvirt daemon to crash. (CVE-2021-3975)

Note that Nessus relies on the presence of the package as reported by the vendor.

Solution

There is no known solution at this time.

See Also

https://access.redhat.com/security/cve/cve-2021-3975

https://ubuntu.com/security/CVE-2021-3975

Plugin Details

Severity: Medium

ID: 224112

File Name: unpatched_CVE_2021_3975.nasl

Version: 1.5

Type: local

Agent: unix

Family: Misc.

Published: 3/5/2025

Updated: 9/14/2025

Supported Sensors: Frictionless Assessment AWS, Frictionless Assessment Azure, Frictionless Assessment Agent, Nessus Agent, Agentless Assessment, Nessus

Risk Information

VPR

Risk Factor: Low

Score: 3.6

CVSS v2

Risk Factor: Low

Base Score: 2.1

Temporal Score: 1.6

Vector: CVSS2#AV:L/AC:L/Au:N/C:N/I:N/A:P

CVSS Score Source: CVE-2021-3975

CVSS v3

Risk Factor: Medium

Base Score: 6.5

Temporal Score: 5.7

Vector: CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Temporal Vector: CVSS:3.0/E:U/RL:O/RC:C

Vulnerability Information

CPE: p-cpe:/a:centos:centos:libvirt-daemon-driver-network, p-cpe:/a:centos:centos:libvirt-daemon-driver-storage-iscsi-direct, cpe:/o:centos:centos:8, p-cpe:/a:redhat:enterprise_linux:libvirt-nss, cpe:/o:canonical:ubuntu_linux:16.04:-:lts, p-cpe:/a:redhat:enterprise_linux:libvirt-daemon-driver-storage, p-cpe:/a:centos:centos:libvirt-wireshark, p-cpe:/a:redhat:enterprise_linux:libvirt-daemon-config-nwfilter, p-cpe:/a:centos:centos:libvirt-client, p-cpe:/a:redhat:enterprise_linux:libvirt-daemon-driver-storage-disk, p-cpe:/a:redhat:enterprise_linux:libvirt-client, p-cpe:/a:redhat:enterprise_linux:libvirt-daemon-driver-qemu, p-cpe:/a:centos:centos:libvirt-daemon-driver-nodedev, p-cpe:/a:centos:centos:libvirt, p-cpe:/a:centos:centos:libvirt-libs, p-cpe:/a:centos:centos:libvirt-daemon-driver-storage, p-cpe:/a:centos:centos:libvirt-daemon-driver-qemu, p-cpe:/a:redhat:enterprise_linux:libvirt, p-cpe:/a:redhat:enterprise_linux:libvirt-daemon-driver-nwfilter, p-cpe:/a:centos:centos:libvirt-daemon-driver-storage-disk, p-cpe:/a:centos:centos:libvirt-devel, p-cpe:/a:redhat:enterprise_linux:libvirt-daemon-driver-storage-iscsi, p-cpe:/a:canonical:ubuntu_linux:libvirt, p-cpe:/a:redhat:enterprise_linux:libvirt-lock-sanlock, p-cpe:/a:redhat:enterprise_linux:libvirt-daemon-kvm, p-cpe:/a:centos:centos:libvirt-lock-sanlock, p-cpe:/a:centos:centos:libvirt-daemon-driver-storage-iscsi, p-cpe:/a:centos:centos:libvirt-daemon-driver-interface, p-cpe:/a:redhat:enterprise_linux:libvirt-daemon-driver-storage-core, cpe:/o:redhat:enterprise_linux:8, p-cpe:/a:redhat:enterprise_linux:libvirt-daemon-config-network, p-cpe:/a:centos:centos:libvirt-daemon-driver-storage-gluster, p-cpe:/a:centos:centos:libvirt-daemon-driver-secret, p-cpe:/a:redhat:enterprise_linux:libvirt-daemon-driver-secret, p-cpe:/a:redhat:enterprise_linux:libvirt-daemon-driver-nodedev, p-cpe:/a:centos:centos:libvirt-daemon-driver-storage-rbd, p-cpe:/a:redhat:enterprise_linux:libvirt-daemon-driver-storage-mpath, p-cpe:/a:centos:centos:libvirt-daemon-config-network, p-cpe:/a:redhat:enterprise_linux:libvirt-daemon-driver-storage-rbd, p-cpe:/a:centos:centos:libvirt-daemon-kvm, p-cpe:/a:centos:centos:libvirt-docs, p-cpe:/a:redhat:enterprise_linux:libvirt-admin, cpe:/a:redhat:advanced_virtualization:8::el8, p-cpe:/a:centos:centos:libvirt-daemon-config-nwfilter, p-cpe:/a:centos:centos:libvirt-daemon-driver-nwfilter, p-cpe:/a:redhat:enterprise_linux:libvirt-daemon-driver-storage-scsi, p-cpe:/a:redhat:enterprise_linux:libvirt-wireshark, p-cpe:/a:redhat:enterprise_linux:libvirt-devel, p-cpe:/a:redhat:enterprise_linux:libvirt-daemon-driver-interface, p-cpe:/a:centos:centos:libvirt-daemon-driver-storage-scsi, p-cpe:/a:redhat:enterprise_linux:libvirt-daemon, p-cpe:/a:redhat:enterprise_linux:libvirt-daemon-driver-storage-iscsi-direct, cpe:/o:canonical:ubuntu_linux:14.04:-:lts, p-cpe:/a:centos:centos:libvirt-daemon, p-cpe:/a:centos:centos:libvirt-daemon-driver-storage-core, p-cpe:/a:redhat:enterprise_linux:libvirt-docs, p-cpe:/a:centos:centos:libvirt-admin, p-cpe:/a:centos:centos:libvirt-daemon-driver-storage-logical, p-cpe:/a:redhat:enterprise_linux:libvirt-daemon-driver-network, p-cpe:/a:redhat:enterprise_linux:libvirt-libs, p-cpe:/a:redhat:enterprise_linux:libvirt-daemon-driver-storage-logical, p-cpe:/a:redhat:enterprise_linux:libvirt-daemon-driver-storage-gluster, p-cpe:/a:redhat:enterprise_linux:libvirt-bash-completion, p-cpe:/a:centos:centos:libvirt-nss, p-cpe:/a:centos:centos:libvirt-bash-completion, p-cpe:/a:centos:centos:libvirt-daemon-driver-storage-mpath

Required KB Items: Host/local_checks_enabled, Host/cpu, global_settings/vendor_unpatched, Host/OS/identifier

Exploit Ease: No known exploits are available

Vulnerability Publication Date: 5/10/2022

Reference Information

CVE: CVE-2021-3975