Low severity · published Mar 9, 2021
CVE-2021-20263
A flaw was found in the virtio-fs shared file system daemon (virtiofsd) of QEMU
3.3
CVSS
0.4%
EPSS
No
On KEV
Description
A flaw was found in the virtio-fs shared file system daemon (virtiofsd) of QEMU. The new 'xattrmap' option may cause the 'security.capability' xattr in the guest to not drop on file write, potentially leading to a modified, privileged executable in the guest. In rare circumstances, this flaw could be used by a malicious user to elevate their privileges within the guest.
CVSS vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N
Attack vector
Local
Complexity
Low
Privileges
Low
User interaction
None
Confidentiality
None
Integrity
Low
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.4% · higher than 31% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
QE
Qemu · Qemu
5.0.0 before 5.2.50 · source: NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2021-20263
CVE.org
https://www.cve.org/CVERecord?id=CVE-2021-20263
Issue Tracking
https://bugzilla.redhat.com/show_bug.cgi?id=1933668
Third Party Advisory
https://security.gentoo.org/glsa/202208-27
Third Party Advisory
https://security.netapp.com/advisory/ntap-20210507-0002/
Mailing List
https://www.openwall.com/lists/oss-security/2021/03/08/1
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