oxenstored: node ownership can be changed by unprivileged clients

2020-12-1512:00:00

Xen Project

xenbits.xen.org

4.9 Medium

CVSS2

Attack Vector

LOCAL

Attack Complexity

LOW

Authentication

NONE

Confidentiality Impact

NONE

Integrity Impact

NONE

Availability Impact

COMPLETE

AV:L/AC:L/Au:N/C:N/I:N/A:C

6 Medium

CVSS3

Attack Vector

LOCAL

Attack Complexity

LOW

Privileges Required

HIGH

User Interaction

NONE

Scope

CHANGED

Confidentiality Impact

NONE

Integrity Impact

NONE

Availability Impact

HIGH

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

0.0004 Low

EPSS

Percentile

14.2%

JSON

ISSUE DESCRIPTION

Nodes in xenstore have an ownership. In oxenstored, a owner could give a node away. But node ownership has quota implications.
Any guest can run another guest out of quota, or create an unbounded number of nodes owned by dom0, thus running xenstored out of memory

IMPACT

A malicious guest administrator can cause denial of service, against a specific guest or against the whole host.

VULNERABLE SYSTEMS

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.