Bug 1195290 (CVE-2015-2044, xsa121)

Summary: CVE-2015-2044 xen: information leak via internal x86 system device emulation (XSA-121)
Product: [Other] Security Response Reporter: Martin Prpič <mprpic>
Component: vulnerabilityAssignee: Red Hat Product Security <security-response-team>
Status: CLOSED NOTABUG QA Contact:
Severity: low Docs Contact:
Priority: low    
Version: unspecifiedCC: drjones, imammedo, jrusnack, mrezanin, pbonzini, pmatouse, rkrcmar, security-response-team, vkuznets
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
Whiteboard:
Fixed In Version: Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2015-02-24 11:43:59 UTC Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:
Bug Depends On:    
Bug Blocks: 1195308    
Attachments:
Description Flags
XSA-121 upstream patch for CVE-2015-2044 none

Description Martin Prpič 2015-02-23 14:49:29 UTC 
ISSUE DESCRIPTION
=================

Emulation routines in the hypervisor dealing with certain system
devices check whether the access size by the guest is a supported one.
When the access size is unsupported these routines failed to set the
data to be returned to the guest for read accesses, so that hypervisor
stack contents are copied into the destination of the operation, thus
becoming visible to the guest.

IMPACT
======

A malicious HVM guest might be able to read sensitive data relating
to other guests.

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

Xen 3.2.x and later are vulnerable.
Xen 3.1.x and earlier have not been inspected.

Only HVM guests can take advantage of this vulnerability.

Only x86 systems are vulnerable. ARM systems are not vulnerable.

MITIGATION
==========

Running only PV guests will avoid this issue.
Comment 1 Martin Prpič 2015-02-23 14:50:59 UTC 
Acknowledgements:

Red Hat would like to thank the Xen project for reporting this issue.
Comment 2 Martin Prpič 2015-02-23 15:06:40 UTC 
Created attachment 994404 [details]
XSA-121 upstream patch for CVE-2015-2044
Comment 5 Petr Matousek 2015-02-24 11:44:29 UTC 
Statement:

Not vulnerable.

This issue does not affect the Xen hypervisor as shipped with Red Hat Enterprise Linux 5.
Comment 6 Martin Prpič 2015-03-06 09:20:08 UTC 
External References:

http://xenbits.xen.org/xsa/advisory-121.html