Bug 1103646 (CVE-2014-4021)

Summary:	CVE-2014-4021 xen: Hypervisor heap contents leaked to guests (xsa-100)
Product:	[Other] Security Response	Reporter:	Petr Matousek <pmatouse>
Component:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED ERRATA	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	CC:	agordeev, dhoward, drjones, imammedo, jkurik, jrusnack, lwang, mrezanin, nobody, pbonzini, pholasek, plougher, rkrcmar, rvrbovsk, security-response-team, vkuznets
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	Bug Fix
Doc Text:	It was found that the Xen hypervisor implementation did not properly clean memory pages previously allocated by the hypervisor. A privileged guest user could potentially use this flaw to read data relating to other guests or the hypervisor itself.	Story Points:	---
Clone Of:		Environment:
Last Closed:	2014-07-23 17:48:14 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:	1103648, 1103649, 1110316
Bug Blocks:	1103651

Description Petr Matousek 2014-06-02 09:32:19 UTC

While memory pages recovered from dying guests are being cleaned to avoid
leaking sensitive information to other guests, memory pages that were in
use by the hypervisor and are eligible to be allocated to guests weren't
being properly cleaned. Such exposure of information would happen through
memory pages freshly allocated to or by the guest.

A malicious guest might be able to read data relating to other guests
or the hypervisor itself.

Acknowledgements:

Red Hat would like to thank the Xen project for reporting this issue. Upstream acknowledges Jan Beulich as the original reporter.

Comment 2 Petr Matousek 2014-06-02 09:34:37 UTC

Statement:

(none)

Comment 6 Petr Matousek 2014-06-17 12:37:49 UTC

Now public via --

  http://seclists.org/oss-sec/2014/q2/549

Comment 7 Petr Matousek 2014-06-17 12:41:18 UTC

Created xen tracking bugs for this issue:

Affects: fedora-all [bug 1110316]

Comment 8 Fedora Update System 2014-07-04 12:29:12 UTC

xen-4.2.4-6.fc19 has been pushed to the Fedora 19 stable repository.  If problems still persist, please make note of it in this bug report.

Comment 9 Fedora Update System 2014-07-04 12:30:30 UTC

xen-4.3.2-6.fc20 has been pushed to the Fedora 20 stable repository.  If problems still persist, please make note of it in this bug report.

Comment 10 errata-xmlrpc 2014-07-23 16:05:29 UTC

This issue has been addressed in following products:

  Red Hat Enterprise Linux 5

Via RHSA-2014:0926 https://rhn.redhat.com/errata/RHSA-2014-0926.html

Comment 11 Martin Prpič 2014-07-28 11:34:33 UTC

IssueDescription:

It was found that the Xen hypervisor implementation did not properly clean memory pages previously allocated by the hypervisor. A privileged guest user could potentially use this flaw to read data relating to other guests or the hypervisor itself.