NULL pointer dereference in Qemu
CVE-2021-20196
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.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H.
EPSS exploit prediction
EPSS: 0.005 (38.9th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 39th percentile — 38.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.005 · newest: 0.005 · change: 0.000
Affected products
- Qemu — versions 5.2.0
- Debian Linux — versions 9.0, 10.0
- Qemu — versions vulnerable up to (including) qemu 5.2.0
Weakness classification (CWE)
Public proof-of-concept exploits
References
- bugs.launchpad.net/qemu/+bug/1912780 (Exploit, Patch, Third Party Advisory)
- www.openwall.com/lists/oss-security/2021/01/28/1 (Patch, Mailing List, Third Party Advisory)
- security.netapp.com/advisory/ntap-20210708-0004/ (Third Party Advisory)
- lists.debian.org/debian-lts-announce/2022/04/msg00002.html (mailing-list, Mailing List, Third Party Advisory)
- lists.debian.org/debian-lts-announce/2022/09/msg00008.html (mailing-list, Mailing List, Third Party Advisory)
Frequently asked questions
- What is CVE-2021-20196?
- CVE-2021-20196 is a medium-severity vulnerability in Qemu, classified under NULL Pointer Dereference. CVSS score: 6.5/10. Published 2021-05-26.
- How severe is CVE-2021-20196?
- Medium severity. CVSS v3 base score is 6.5 out of 10.
- Is CVE-2021-20196 known to be exploited?
- 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.