Bug 1009817 - (CVE-2013-4361) CVE-2013-4361 Kernel: Xen: Xsa-66: information leak through fbld instruction emulation
CVE-2013-4361 Kernel: Xen: Xsa-66: information leak through fbld instruction ...
Status: CLOSED NOTABUG
Product: Security Response
Classification: Other
Component: vulnerability (Show other bugs)
unspecified
All Linux
low Severity low
: ---
: ---
Assigned To: Red Hat Product Security
impact=low,public=20130930,reported=2...
: Security
Depends On: 1013748
Blocks: 1009366
  Show dependency treegraph
 
Reported: 2013-09-19 04:31 EDT by Prasad J Pandit
Modified: 2013-09-30 13:14 EDT (History)
6 users (show)

See Also:
Fixed In Version:
Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of:
Environment:
Last Closed: 2013-09-30 13:10:26 EDT
Type: ---
Regression: ---
Mount Type: ---
Documentation: ---
CRM:
Verified Versions:
Category: ---
oVirt Team: ---
RHEL 7.3 requirements from Atomic Host:


Attachments (Terms of Use)

  None (edit)
Description Prasad J Pandit 2013-09-19 04:31:26 EDT
The emulation of the fbld instruction (which is used during I/O
emulation) uses the wrong variable for the source effective address.
As a result, the actual address used is an uninitialised bit pattern
from the stack.

A malicious guest might be able to find out information about the
contents of the hypervisor stack, by observing which values are
actually being used by fbld and inferring what the address must have
been. Depending on the actual values on the stack this attack might
be very difficult to carry out.

A malicious guest could use this flaw to access memory bytes related to other
guests.
Comment 1 Prasad J Pandit 2013-09-19 04:38:19 EDT
Statement:

This issue does not affect the versions of the kernel-xen package as shipped with Red Hat Enterprise Linux 5.

This issue does not affect the versions of the Linux kernel package as shipped with Red Hat Enterprise Linux 6 and Red Hat Enterprise MRG as it does not have support for Xen hypervisor.
Comment 2 Prasad J Pandit 2013-09-19 04:40:23 EDT
Acknowledgement:

Red Hat would like to thank the Xen project for reporting this issue.
Comment 5 Vincent Danen 2013-09-30 13:10:26 EDT
This is now public:

http://www.openwall.com/lists/oss-security/2013/09/30/3
Comment 6 Vincent Danen 2013-09-30 13:14:29 EDT
Created xen tracking bugs for this issue:

Affects: fedora-all [bug 1013748]

Note You need to log in before you can comment on or make changes to this bug.