Medium severity · published Jan 25, 2022
CVE-2021-4145
A NULL pointer dereference issue was found in the block mirror layer of QEMU in versions prior to 6.2.0
6.5
CVSS
0.4%
EPSS
No
On KEV
Description
A NULL pointer dereference issue was found in the block mirror layer of QEMU in versions prior to 6.2.0. The `self` pointer is dereferenced in mirror_wait_on_conflicts() without ensuring that it's not NULL. A malicious unprivileged user within the guest could use this flaw to crash the QEMU process on the host when writing data reaches the threshold of mirroring node.
CVSS vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H
Attack vector
Local
Complexity
Low
Privileges
Low
User interaction
None
Confidentiality
None
Integrity
None
Availability
High
Scope
Changed
Exploitation
Is it being used?
Exploit prediction (EPSS)0.4% · higher than 33% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
EL
Enterprise Linux · Redhat
8.0 · source: NVD
QE
Qemu · Qemu
6.1.0; 6.1.0; 6.1.0; 6.1.0; 6.1.0; 6.1.0 · source: NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2021-4145
CVE.org
https://www.cve.org/CVERecord?id=CVE-2021-4145
Issue Tracking
https://bugzilla.redhat.com/show_bug.cgi?id=2034602
Patch
https://gitlab.com/qemu-project/qemu/-/commit/66fed30c9cd11854fc878a4eceb507e915d7c9cd
Third Party Advisory
https://security.gentoo.org/glsa/202208-27
Third Party Advisory
https://security.netapp.com/advisory/ntap-20220311-0004/
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