Bug 1009817 (CVE-2013-4361) - CVE-2013-4361 Kernel: Xen: Xsa-66: information leak through fbld instruction emulation
Summary: CVE-2013-4361 Kernel: Xen: Xsa-66: information leak through fbld instruction ...
Keywords:
Status: CLOSED NOTABUG
Alias: CVE-2013-4361
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
low
low
Target Milestone: ---
Assignee: Red Hat Product Security
QA Contact:
URL:
Whiteboard:
Depends On: 1013748
Blocks: 1009366
TreeView+ depends on / blocked
 
Reported: 2013-09-19 08:31 UTC by Prasad Pandit
Modified: 2021-02-17 07:20 UTC (History)
6 users (show)

Fixed In Version:
Doc Type: Bug Fix
Doc Text:
Clone Of:
Environment:
Last Closed: 2013-09-30 17:10:26 UTC

Attachments (Terms of Use)

Description Prasad Pandit 2013-09-19 08:31:26 UTC 
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 Pandit 2013-09-19 08:38:19 UTC 
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 Pandit 2013-09-19 08:40:23 UTC 
Acknowledgement:

Red Hat would like to thank the Xen project for reporting this issue.
Comment 5 Vincent Danen 2013-09-30 17:10:26 UTC 
This is now public:

http://www.openwall.com/lists/oss-security/2013/09/30/3
Comment 6 Vincent Danen 2013-09-30 17:14:29 UTC 
Created xen tracking bugs for this issue:

Affects: fedora-all [bug 1013748]
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