CVE-2021-20196

MediumCVSS 6.5/10Last modified Jun 17, 2026

Description

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.

Metrics

CVSS 3.1 6.5/10CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H

Weakness enumeration

CWE-476

Affected software

Vendor	Product	Versions
n/a	qemu	vulnerable up to (including) qemu 5.2.0

References

https://bugs.launchpad.net/qemu/+bug/1912780Exploit, Patch, Third Party Advisory
https://lists.debian.org/debian-lts-announce/2022/04/msg00002.htmlMailing List, Third Party Advisory
https://lists.debian.org/debian-lts-announce/2022/09/msg00008.htmlMailing List, Third Party Advisory
https://security.netapp.com/advisory/ntap-20210708-0004/Third Party Advisory
https://www.openwall.com/lists/oss-security/2021/01/28/1Mailing List, Patch, Third Party Advisory
https://bugs.launchpad.net/qemu/+bug/1912780Exploit, Patch, Third Party Advisory
https://lists.debian.org/debian-lts-announce/2022/04/msg00002.htmlMailing List, Third Party Advisory
https://lists.debian.org/debian-lts-announce/2022/09/msg00008.htmlMailing List, Third Party Advisory
https://security.netapp.com/advisory/ntap-20210708-0004/Third Party Advisory
https://www.openwall.com/lists/oss-security/2021/01/28/1Mailing List, Patch, Third Party Advisory

Timeline

Published: May 26, 2021
Last modified: Jun 17, 2026
NVD status: Modified

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