Instituto Nacional de ciberseguridad. Sección Incibe
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CVE-2020-29482

Severity CVSS v4.0:
Pending analysis
Type:
CWE-426 Untrusted Search Path
Publication date:
15/12/2020
Last modified:
07/11/2023

Description

An issue was discovered in Xen through 4.14.x. A guest may access xenstore paths via absolute paths containing a full pathname, or via a relative path, which implicitly includes /local/domain/$DOMID for their own domain id. Management tools must access paths in guests' namespaces, necessarily using absolute paths. oxenstored imposes a pathname limit that is applied solely to the relative or absolute path specified by the client. Therefore, a guest can create paths in its own namespace which are too long for management tools to access. Depending on the toolstack in use, a malicious guest administrator might cause some management tools and debugging operations to fail. For example, a guest administrator can cause "xenstore-ls -r" to fail. However, a guest administrator cannot prevent the host administrator from tearing down the domain. 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:H/UI:N/S:C/C:N/I:N/A:H CVSS v3.1 Severity and Metrics:

Base Score: 6.00 MEDIUM
Vector: CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:N/I:N/A:H

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

Base Score 3.x
6.00
Severity 3.x
MEDIUM
Vector 2.0
AV:L/AC:L/Au:N/C:N/I:N/A:C CVSS v2.0 Severity and Metrics:

Base Score: 4.90 MEDIUM
Vector: AV:L/AC:L/Au:N/C:N/I:N/A:C

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

Base Score 2.0
4.90
Severity 2.0
MEDIUM

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


References to Advisories, Solutions, and Tools