CVE-2021-26933

Severity CVSS v4.0:

Pending analysis

Type:

Unavailable / Other

Publication date:

17/02/2021

Last modified:

07/11/2023

Description

An issue was discovered in Xen 4.9 through 4.14.x. On Arm, a guest is allowed to control whether memory accesses are bypassing the cache. This means that Xen needs to ensure that all writes (such as the ones during scrubbing) have reached the memory before handing over the page to a guest. Unfortunately, the operation to clean the cache is happening before checking if the page was scrubbed. Therefore there is no guarantee when all the writes will reach the memory.

Impact

Vector 3.x

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N CVSS v3.1 Severity and Metrics:

Base Score: 5.50 MEDIUM
Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

Attack Vector (AV): Local
Attack Complexity (AC): Low
Privileges Required (PR): Low
User Interaction (UI): None
Scope (S): Unchanged
Confidentiality (C): High
Integrity (I): None
Availability (A): None

Base Score 3.x

5.50

Severity 3.x

MEDIUM

Vector 2.0

AV:L/AC:L/Au:N/C:P/I:N/A:N CVSS v2.0 Severity and Metrics:

Base Score: 2.10 LOW
Vector: AV:L/AC:L/Au:N/C:P/I:N/A:N

Attack Vector (AV): Local
Attack Complexity (AC): Low
Authentication (Au): None
Confidentiality (C): Physical
Integrity (I): None
Availability (A): None

Base Score 2.0

2.10

Severity 2.0

LOW

Vulnerable products and versions

CPE	From	Up to
cpe:2.3:o:xen:xen:::::::arm:*	4.9.0 (including)	4.14.1 (including)
cpe:2.3:o:fedoraproject:fedora:32:::::::*
cpe:2.3:o:fedoraproject:fedora:33:::::::*
cpe:2.3:o:debian:debian_linux:10.0:::::::*

To consult the complete list of CPE names with products and versions, see this page

CVE-2021-26933

Description

Impact

Vulnerable products and versions

References to Advisories, Solutions, and Tools