CVE-2021-20196: Null Pointer Dereference
First published: Fri 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.
Credit: secalert@redhat.com
| Affected Software | Affected Version | How to fix |
|---|---|---|
| QEMU KVM | =5.2.0 | |
| Debian GNU/Linux | =9.0 | |
| Debian GNU/Linux | =10.0 | |
| debian/qemu | <=1:5.2+dfsg-11+deb11u2 | 1:5.2+dfsg-11+deb11u3 1:7.2+dfsg-7+deb12u12 1:9.2.0+ds-5 1:9.2.1+ds-1 |
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Reference Links
- https://bugs.launchpad.net/qemu/+bug/1912780
- https://lists.debian.org/debian-lts-announce/2022/04/msg00002.html
- https://lists.debian.org/debian-lts-announce/2022/09/msg00008.html
- https://security.netapp.com/advisory/ntap-20210708-0004/
- https://www.openwall.com/lists/oss-security/2021/01/28/1
- https://launchpad.net/bugs/cve/CVE-2021-20196
- https://lists.nongnu.org/archive/html/qemu-devel/2021-01/msg05986.html
- https://bugzilla.redhat.com/show_bug.cgi/show_bug.cgi?id=1919532
- https://bugzilla.redhat.com/show_bug.cgi/show_bug.cgi?id=1919533
- https://access.redhat.com/support/policy/updates/errata/
- https://access.redhat.com/errata/RHSA-2022:0325
- https://access.redhat.com/errata/RHSA-2022:0397
- https://access.redhat.com/security/cve/cve-2021-20196
- https://access.redhat.com/errata/RHSA-2022:1759
- https://bugzilla.redhat.com/show_bug.cgi?id=1919210
- https://gitlab.com/qemu-project/qemu/-/issues/338
- https://gitlab.com/qemu-project/qemu/-/commit/1ab95af033a419e7a64e2d58e67dd96b20af5233
- https://security-tracker.debian.org/tracker/CVE-2021-20196
- https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-20196
- https://nvd.nist.gov/vuln/detail/CVE-2021-20196
- https://ubuntu.com/security/CVE-2021-20196
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.
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