Bug 851139 - (CVE-2012-3494) CVE-2012-3494 kernel: xen: hypercall set_debugreg vulnerability
CVE-2012-3494 kernel: xen: hypercall set_debugreg vulnerability
Status: NEW
Product: Security Response
Classification: Other
Component: vulnerability (Show other bugs)
All Linux
medium Severity medium
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Assigned To: Red Hat Product Security
: Security
Depends On: 854585
Blocks: 851204
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Reported: 2012-08-23 06:33 EDT by Petr Matousek
Modified: 2015-11-06 11:19 EST (History)
5 users (show)

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Doc Type: Bug Fix
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Description Petr Matousek 2012-08-23 06:33:56 EDT
set_debugreg allows writes to reserved bits of the DR7 debug control register on x86-64.
A malicious guest can cause the host to crash, leading to a DoS.
If the vulnerable hypervisor is run on future hardware, the impact of the vulnerability might be widened depending on the future assignment of the currently-reserved debug register bits.

All systems running 64-bit paravirtualised guests are vulnerable to this issue.


Red Hat would like to thank the Xen project for reporting this issue.
Comment 3 Petr Matousek 2012-08-23 07:29:41 EDT

Not vulnerable.

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

This issue did not affect Red Hat Enterprise Linux 6 and Red Hat Enterprise MRG as we did not have support for Xen hypervisor.
Comment 4 Petr Matousek 2012-09-05 07:38:39 EDT
Now public via:

Comment 5 Petr Matousek 2012-09-05 07:40:03 EDT
Created xen tracking bugs for this issue

Affects: fedora-all [bug 854585]
Comment 6 Fedora Update System 2012-09-17 13:59:46 EDT
xen-4.1.3-2.fc16 has been pushed to the Fedora 16 stable repository.  If problems still persist, please make note of it in this bug report.

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