Home/CVE/A NULL pointer dereference flaw was found in the floppy disk emulator of QEMU. This issue occurs while processing read/w
CVE

CVE-2021-20196

A NULL pointer dereference flaw was found in the floppy disk emulator of QEMU. This issue occurs while processing read/w

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.

MEDIUM · CVSS 6.5 EPSS 0.00039
Schedule remediation
  • Public exploit or PoC is available
Sigma rules1 YARA rules0
⬡

Weakness Classification

CWE-476NULL Pointer Dereference
CWE-476NULL Pointer Dereference
▤

Affected Products & Versions

2
qemuall versions
debian linuxall versions
⚠

Public Exploits & PoCs

1
pocbugs.launchpad.net · 1912780bugs.launchpad.net
◈

Sigma Hunt Rules

1
Exact rules name this CVE ID. Product rules name an affected product in their title. Related rules cover techniques used by actors who exploited this CVE. Showing the most relevant matches; the complete related set is on the full drill-down.
productmediumPotentially Suspicious Usage Of Qemu
▣

Scoring & Timeline

6.5
MEDIUM · CVSS v3.1 · secalert@redhat.com
View on NVD
Attack Vector
Network Adjacent Local Physical
Attack Complexity
Low High
Privileges Required
None Low High
User Interaction
None Required
Scope
Unchanged Changed
Confidentiality
None Low High
Integrity
None Low High
Availability
None Low High
Published to NVD26 May 2021 · 10:15 PM
CVSS VectorCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H
⚑

Vendor Advisories

10
suse-csafSUSE-SU-2022:1151-1
usnUSN-5307-1
suse-csafSUSE-SU-2022:0210-2
rhsaRHSA-2022:1759Moderate
suse-csafopenSUSE-SU-2022:0210-1
🔗

References & Sources

4
Source URLs (vendor pages, mailing lists, write-ups). Exploit/PoC links are in their own section above to avoid duplication.
https://lists.debian.org/debian-lts-announce/2022/04/msg00002.htmlMailing ListThird Party Advisory
https://lists.debian.org/debian-lts-announce/2022/09/msg00008.htmlMailing ListThird Party Advisory
https://security.netapp.com/advisory/ntap-20210708-0004/Third Party Advisory
https://www.openwall.com/lists/oss-security/2021/01/28/1Mailing ListPatchThird Party Advisory
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