CVE-2020-29482 Information

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 nstore-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.

CVSS Vector

CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:N/I:N/A:H

Reference

https://xenbits.xenproject.org/xsa/advisory-323.html https://www.debian.org/security/2020/dsa-4812 https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/OBLV6L6Q24PPQ2CRFXDX4Q76KU776GKI/ https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/2C6M6S3CIMEBACH6O7V4H2VDANMO6TVA/

Attack Complexity

LOW

Privileges Required

HIGH

User Interaction Required

HIGH

Scope

NONE

Confidentiality Impact

CHANGED

Integrity Impact

NONE

Availability Impact

NONE

Base Score

HIGH

Base Severity

6.0