CVE-2021-20263

Gentoo Linux Security Advisory 202208-27

Severity Score

3.3

*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

*Multiple Sources

Exploited in Wild

*KEV

Decision

*SSVC

Descriptions

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.

Se encontró un fallo en el demonio del sistema de archivos compartidos virtio-fs (virtiofsd) de QEMU. La nueva opción "xattrmap" puede causar que el xattr "security.capability" en el invitado no caiga en la escritura del archivo, potencialmente conllevando a un ejecutable privilegiado modificado en el invitado. En raras ocasiones, un usuario malicioso podría usar este fallo para elevar sus privilegios dentro del invitado

Multiple vulnerabilities have been discovered in QEMU, the worst of which could result in remote code execution (guest sandbox escape). Versions less than 7.0.0 are affected.

*Credits: N/A

Attack Vector

Local

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

Low

Availability

None

Attack Vector

Local

Attack Complexity

Low

Authentication

None

Confidentiality

None

Integrity

Partial

Availability

None

* Common Vulnerability Scoring System

SSVC

Decision:-

Exploitation

Automatable

Tech. Impact

* Organization's Worst-case Scenario

Timeline

2020-12-17 CVE Reserved
2021-03-09 CVE Published
2024-08-03 CVE Updated
2025-03-30 EPSS Updated
---------- Exploited in Wild
---------- KEV Due Date
---------- First Exploit

CWE

CWE-281: Improper Preservation of Permissions

CAPEC

References (4)

URL	Tag	Source
https://security.netapp.com/advisory/ntap-20210507-0002	Third Party Advisory

URL	Date	SRC

URL	Date	SRC
https://bugzilla.redhat.com/show_bug.cgi?id=1933668	2022-09-30
https://www.openwall.com/lists/oss-security/2021/03/08/1	2022-09-30

URL	Date	SRC
https://security.gentoo.org/glsa/202208-27	2022-09-30

Affected Vendors, Products, and Versions

Vendor		Product				Version		Other		Status
Vendor	Product	Version	Other	Status	<-- -->	Vendor	Product	Version	Other	Status
Qemu Search vendor "Qemu"		Qemu Search vendor "Qemu" for product "Qemu"				>= 5.0.0 < 5.2.50 Search vendor "Qemu" for product "Qemu" and version " >= 5.0.0 < 5.2.50"		-		Affected