CVE Vulnerabilities

CVE-2021-20196

NULL Pointer Dereference

Published: May 26, 2021 | Modified: Nov 21, 2024
CVSS 3.x
6.5
MEDIUM
Source:
NVD
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H
CVSS 2.x
2.1 LOW
AV:L/AC:L/Au:N/C:N/I:N/A:P
RedHat/V2
RedHat/V3
3.2 LOW
CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:N/I:N/A:L
Ubuntu
LOW

A NULL pointer dereference flaw was found in the floppy disk emulator of QEMU. This issue occurs while processing read/write ioport commands if the selected floppy drive is not initialized with a block device. This flaw allows a privileged guest user to crash the QEMU process on the host, resulting in a denial of service. The highest threat from this vulnerability is to system availability.

Weakness

The product dereferences a pointer that it expects to be valid but is NULL.

Affected Software

Name Vendor Start Version End Version
Qemu Qemu 5.2.0 (including) 5.2.0 (including)
Advanced Virtualization for RHEL 8.4.0.EUS RedHat virt:av-8040020220110150817.522a0ee4 *
Advanced Virtualization for RHEL 8.4.0.EUS RedHat virt-devel:av-8040020220110150817.522a0ee4 *
Advanced Virtualization for RHEL 8.5.0.Z RedHat virt:av-8050020220115095224.c5368500 *
Advanced Virtualization for RHEL 8.5.0.Z RedHat virt-devel:av-8050020220115095224.c5368500 *
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-legacy/trusty *
Qemu Ubuntu esm-infra/bionic *
Qemu Ubuntu esm-infra/focal *
Qemu Ubuntu esm-infra/xenial *
Qemu Ubuntu focal *
Qemu Ubuntu groovy *
Qemu Ubuntu hirsute *
Qemu Ubuntu impish *
Qemu Ubuntu jammy *
Qemu Ubuntu kinetic *
Qemu Ubuntu lunar *
Qemu Ubuntu mantic *
Qemu Ubuntu noble *
Qemu Ubuntu oracular *
Qemu Ubuntu plucky *
Qemu Ubuntu questing *
Qemu Ubuntu trusty *
Qemu Ubuntu trusty/esm *
Qemu Ubuntu xenial *
Qemu-kvm Ubuntu precise/esm *
Xen Ubuntu bionic *
Xen Ubuntu focal *
Xen Ubuntu groovy *
Xen Ubuntu hirsute *
Xen Ubuntu impish *
Xen Ubuntu kinetic *
Xen Ubuntu lunar *
Xen Ubuntu mantic *
Xen Ubuntu oracular *
Xen Ubuntu trusty *
Xen Ubuntu xenial *

Potential Mitigations

References