CVE-2021-20196: Null Pointer Dereference

Published Jan 22, 2021
·
Updated

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.

Other sources

A NULL pointer dereference issue was found in the Floopy disk emulator of QEMU. It could occur while processing read/write ioport commands, if the selected Floopy drive is not initialised with a block device. A privileged guest user could use this flaw to crash the QEMU process on the host resulting in DoS scenario.

Upstream patch: --------------- -> https://lists.nongnu.org/archive/html/qemu-devel/2021-01/msg05986.html

Red Hat

Affected Software

4 affected componentsFixes available
Qemu Qemu=5.2.0
Debian Debian Linux=9.0
Debian Debian Linux=10.0
debian/qemu<=1:5.2+dfsg-11+deb11u2
1:5.2+dfsg-11+deb11u31:7.2+dfsg-7+deb12u121:10.0.0~rc2+ds-21:10.0.0~rc3+ds-2

Event History

Jan 22, 2021
Data Sourced
via Red Hat·12:02 PM
DescriptionSeverityAffected Software
May 26, 2021
CVE Published
via MITRE·09:16 PM
Data Sourced
via MITRE·09:16 PM
DescriptionWeakness
Jan 11, 2024
Data Sourced
via Launchpad·11:53 PM
Description
Sep 16, 2024
Data Sourced
via Ubuntu·01:45 AM
RemedyDescriptionSeverityAffected Software
Mar 31, 2025
Data Sourced
via Debian·01:07 AM
DescriptionAffected Software

Frequently Asked Questions

1

What is the vulnerability ID of this QEMU vulnerability?

The vulnerability ID of this QEMU vulnerability is CVE-2021-20196.

2

What is the severity level of the QEMU vulnerability CVE-2021-20196?

The severity level of the QEMU vulnerability CVE-2021-20196 is medium with a CVSS score of 6.5.

3

How does the QEMU vulnerability CVE-2021-20196 occur?

The QEMU vulnerability CVE-2021-20196 occurs due to a NULL pointer dereference flaw in the floppy disk emulator.

4

What are the affected software versions of the QEMU vulnerability CVE-2021-20196?

The affected software versions of the QEMU vulnerability CVE-2021-20196 are QEMU 5.2.0, Debian Debian Linux 9.0, and Debian Debian Linux 10.0.

5

Is there a fix available for the QEMU vulnerability CVE-2021-20196?

Yes, there are fixes available for the QEMU vulnerability CVE-2021-20196. Please refer to the provided references for more information.

Contact

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