Bug 1652231 (CVE-2018-19963, XSA-276) - CVE-2018-19963 xsa276 xen: resource accounting issues in x86 IOREQ server handling (XSA-276)
Summary: CVE-2018-19963 xsa276 xen: resource accounting issues in x86 IOREQ server han...
Keywords:
Status: CLOSED WONTFIX
Alias: CVE-2018-19963, XSA-276
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
medium
medium
Target Milestone: ---
Assignee: Red Hat Product Security
QA Contact:
URL:
Whiteboard:
Depends On: 1652251
Blocks:
TreeView+ depends on / blocked
 
Reported: 2018-11-21 17:58 UTC by Pedro Sampaio
Modified: 2019-09-29 15:03 UTC (History)
12 users (show)

Fixed In Version:
Doc Type: If docs needed, set a value
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Clone Of:
Environment:
Last Closed: 2019-06-10 10:43:09 UTC


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Description Pedro Sampaio 2018-11-21 17:58:21 UTC
ISSUE DESCRIPTION
=================

Allocation of pages used to communicate with external emulators did not
follow certain principles that are required for proper life cycle
management of guest exposed pages.

IMPACT
======

A compromised DM stubdomain may cause Xen to crash, resulting in a DoS
(Denial of Service) affecting the entire host. Privilege escalation
as well as information leaks cannot be ruled out.

VULNERABLE SYSTEMS
==================

Only Xen 4.11 is affected by this vulnerability. Xen 4.10 and older are
not affected by this vulnerability.

Only systems running HVM guests with their devicemodels in a
stubdomain are considered vulnerable. Note that attackers also need
to exploit the devicemodel in order to have access to this
vulnerability.

Arm guests cannot leverage this vulnerability.

MITIGATION
==========

Running only PV guests will avoid this vulnerability.

(The security of a Xen system using stub domains is still better than
with a qemu-dm running as an unrestricted dom0 process. Therefore
users with these configurations should not switch to an unrestricted
dom0 qemu-dm.)

References:

https://xenbits.xen.org/xsa/advisory-276.html

Comment 1 Pedro Sampaio 2018-11-21 17:58:36 UTC
Acknowledgments:

Name: the Xen project
Upstream: Julien Grall (ARM)

Comment 2 Pedro Sampaio 2018-11-21 18:11:19 UTC
Created xen tracking bugs for this issue:

Affects: fedora-all [bug 1652251]


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