CVE Vulnerabilities

CVE-2021-3748

Use After Free

Published: Mar 23, 2022 | Modified: Nov 21, 2024
CVSS 3.x
7.5
HIGH
Source:
NVD
CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:H
CVSS 2.x
6.9 MEDIUM
AV:L/AC:M/Au:N/C:C/I:C/A:C
RedHat/V2
RedHat/V3
7.5 MODERATE
CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:H
Ubuntu
MEDIUM

A use-after-free vulnerability was found in the virtio-net device of QEMU. It could occur when the descriptors 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.

Weakness

The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory “belongs” to the code that operates on the new pointer.

Affected Software

Name Vendor Start Version End Version
Qemu Qemu 0.10.0 (including) 6.2.0 (excluding)
Advanced Virtualization for RHEL 8.2.1 RedHat virt:8.2-8020120211120005046.863bb0db *
Advanced Virtualization for RHEL 8.2.1 RedHat virt-devel:8.2-8020120211120005046.863bb0db *
Advanced Virtualization for RHEL 8.4.0.Z RedHat virt:av-8040020211022000504.522a0ee4 *
Advanced Virtualization for RHEL 8.4.0.Z RedHat virt-devel:av-8040020211022000504.522a0ee4 *
Red Hat Enterprise Linux 8 RedHat virt-devel:rhel-8060020220408104655.d63f516d *
Red Hat Enterprise Linux 8 RedHat virt:rhel-8060020220408104655.d63f516d *
Qemu Ubuntu bionic *
Qemu Ubuntu devel *
Qemu Ubuntu esm-infra/bionic *
Qemu Ubuntu esm-infra/focal *
Qemu Ubuntu focal *
Qemu Ubuntu hirsute *
Qemu Ubuntu impish *
Qemu Ubuntu jammy *
Qemu Ubuntu kinetic *
Qemu Ubuntu trusty *
Qemu Ubuntu xenial *

Potential Mitigations

References