CVE-2021-20196: Null Pointer Dereference
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
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
debian/qemuto a version that resolves this vulnerability.Fixed in 1:5.2+dfsg-11+deb11u3Fixed in 1:7.2+dfsg-7+deb12u12Fixed in 1:10.0.0~rc2+ds-2Fixed in 1:10.0.0~rc3+ds-2 - Upgrade
Upgrade
alpine/qemuto a version that resolves this vulnerability.Fixed in 6.1.1-r0
Event History
Frequently Asked Questions
What is the vulnerability ID of this QEMU vulnerability?
The vulnerability ID of this QEMU vulnerability is CVE-2021-20196.
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.
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.
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.
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.