Linux Distros Unpatched Vulnerability : CVE-2021-3748

high Nessus Plugin ID 223958

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 vulnerability was found in the virtio-net device of QEMU. It could occur when the descriptor's address belongs to the non direct access region, due to num_buffers being set after the virtqueue elem has been unmapped. A malicious guest could use this flaw to crash QEMU, resulting in a denial of service condition, or potentially execute code on the host with the privileges of the QEMU process. (CVE-2021-3748)

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-2021-3748

Plugin Details

Severity: High

ID: 223958

File Name: unpatched_CVE_2021_3748.nasl

Version: 1.3

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: High

Score: 7.3

CVSS v2

Risk Factor: Medium

Base Score: 6.9

Temporal Score: 5.1

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

CVSS Score Source: CVE-2021-3748

CVSS v3

Risk Factor: High

Base Score: 7.5

Temporal Score: 6.5

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

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

Vulnerability Information

CPE: p-cpe:/a:centos:centos:qemu-kvm-common, p-cpe:/a:redhat:enterprise_linux:qemu-kvm-core, p-cpe:/a:centos:centos:qemu-kvm-block-ssh, p-cpe:/a:centos:centos:qemu-kvm-ui-opengl, p-cpe:/a:redhat:enterprise_linux:qemu-guest-agent, cpe:/o:centos:centos:8, p-cpe:/a:centos:centos:qemu-kvm-block-gluster, p-cpe:/a:centos:centos:qemu-kiwi, p-cpe:/a:centos:centos:qemu-guest-agent, p-cpe:/a:centos:centos:qemu-kvm-hw-usbredir, p-cpe:/a:redhat:enterprise_linux:qemu-kvm-docs, p-cpe:/a:centos:centos:qemu-img, p-cpe:/a:redhat:enterprise_linux:qemu-img, cpe:/o:redhat:enterprise_linux:8, p-cpe:/a:redhat:enterprise_linux:qemu-kvm-block-iscsi, p-cpe:/a:centos:centos:qemu-kvm-block-iscsi, p-cpe:/a:redhat:enterprise_linux:qemu-kvm-hw-usbredir, p-cpe:/a:redhat:enterprise_linux:qemu-kvm-block-gluster, p-cpe:/a:centos:centos:qemu-kvm-tests, p-cpe:/a:redhat:enterprise_linux:qemu-kvm-common, p-cpe:/a:centos:centos:qemu-kvm-docs, p-cpe:/a:redhat:enterprise_linux:qemu-kvm-block-rbd, p-cpe:/a:centos:centos:qemu-kvm, p-cpe:/a:centos:centos:qemu-kvm-ui-spice, p-cpe:/a:redhat:enterprise_linux:qemu-kvm-tests, p-cpe:/a:redhat:enterprise_linux:qemu-kiwi, cpe:/a:redhat:advanced_virtualization:8::el8, p-cpe:/a:centos:centos:qemu-kvm-block-curl, p-cpe:/a:centos:centos:qemu-kvm-core, p-cpe:/a:redhat:enterprise_linux:qemu-kvm-ui-spice, p-cpe:/a:redhat:enterprise_linux:qemu-kvm, p-cpe:/a:centos:centos:qemu-kvm-block-rbd, p-cpe:/a:redhat:enterprise_linux:qemu-kvm-block-ssh, p-cpe:/a:redhat:enterprise_linux:qemu-kvm-block-curl, p-cpe:/a:redhat:enterprise_linux:qemu-kvm-ui-opengl

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: 12/9/2021

Reference Information

CVE: CVE-2021-3748