CVE-2020-29479

Severity CVSS v4.0:

Pending analysis

Type:

Unavailable / Other

Publication date:

15/12/2020

Last modified:

07/11/2023

Description

An issue was discovered in Xen through 4.14.x. In the Ocaml xenstored implementation, the internal representation of the tree has special cases for the root node, because this node has no parent. Unfortunately, permissions were not checked for certain operations on the root node. Unprivileged guests can get and modify permissions, list, and delete the root node. (Deleting the whole xenstore tree is a host-wide denial of service.) Achieving xenstore write access is also possible. All systems using oxenstored are vulnerable. Building and using oxenstored is the default in the upstream Xen distribution, if the Ocaml compiler is available. Systems using C xenstored are not vulnerable.

Impact

Vector 3.x

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

Base Score: 8.80 HIGH
Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

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

Base Score 3.x

8.80

Severity 3.x

HIGH

Vector 2.0

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

Base Score: 7.20 HIGH
Vector: AV:L/AC:L/Au:N/C:C/I:C/A:C

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

Base Score 2.0

7.20

Severity 2.0

HIGH

Vulnerable products and versions

CPE	From	Up to
cpe:2.3:o:xen:xen::::::::		4.14.0 (including)
cpe:2.3:o:debian:debian_linux:10.0:::::::*
cpe:2.3:o:fedoraproject:fedora:32:::::::*
cpe:2.3:o:fedoraproject:fedora:33:::::::*

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

CVE-2020-29479

Description

Impact

Vulnerable products and versions

References to Advisories, Solutions, and Tools