Protect yourself against future threats.
-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA256
===========================================================================
AUSCERT External Security Bulletin Redistribution
ESB-2019.1777
FreeBSD: Microcode updates available for Microarchitectural
Data Sampling (MDS) vulnerabilities
17 May 2019
===========================================================================
AusCERT Security Bulletin Summary
---------------------------------
Product: Intel microcode
Publisher: FreeBSD
Operating System: FreeBSD
Impact/Access: Access Privileged Data -- Existing Account
Resolution: Patch/Upgrade
CVE Names: CVE-2019-11091 CVE-2018-12130 CVE-2018-12127
CVE-2018-12126
Reference: ASB-2019.0138
Original Bulletin:
https://security.freebsd.org/advisories/FreeBSD-SA-19:07.mds.asc
- --------------------------BEGIN INCLUDED TEXT--------------------
- -----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA512
=============================================================================
FreeBSD-SA-19:07.mds Security Advisory
The FreeBSD Project
Topic: Microarchitectural Data Sampling (MDS)
Category: core
Module: kernel
Announced: 2019-05-14
Credits: Refer to Intel's security advisory at the URL below for
detailed acknowledgements.
Affects: All supported versions of FreeBSD.
Corrected: 2019-05-14 17:04:00 UTC (stable/12, 12.0-STABLE)
2019-05-14 23:19:08 UTC (releng/12.0, 12.0-RELEASE-p4)
2019-05-14 17:05:02 UTC (stable/11, 11.3-PRERELEASE)
2019-05-14 23:20:16 UTC (releng/11.2, 11.2-RELEASE-p10)
CVE Name: CVE-2018-12126, CVE-2018-12127, CVE-2018-12130,
CVE-2019-11091
For general information regarding FreeBSD Security Advisories,
including descriptions of the fields above, security branches, and the
following sections, please visit <URL:https://security.FreeBSD.org/>.
0. Revision history
v1.0 2019-05-14 Initial release.
v1.1 2019-05-15 Fixed date on microcode update package.
v1.2 2019-05-15 Userland startup microcode update details added.
Add language specifying which manufacturers is affected.
I. Background
Modern processors make use of speculative execution, an optimization
technique which performs some action in advance of knowing whether the
result will actually be used.
II. Problem Description
On some Intel processors utilizing speculative execution a local process may
be able to infer stale information from microarchitectural buffers to obtain
a memory disclosure.
III. Impact
An attacker may be able to read secret data from the kernel or from a
process when executing untrusted code (for example, in a web browser).
IV. Workaround
No workaround is available.
Only Intel x86 based processors are affected. x86 processors from other
manufacturers (eg, AMD) are not believed to be vulnerable.
Systems with users or processors in different trust domains should disable
Hyper-Threading by setting the machdep.hyperthreading_allowed tunable to 0:
# echo 'machdep.hyperthreading_allowed=0 >> /boot/loader.conf'
# shutdown -r +10min "Security update"
V. Solution
Perform one of the following:
Update CPU microcode, upgrade your vulnerable system to a supported FreeBSD
stable or release / security branch (releng) dated after the correction date,
evaluate mitigation and Hyper Threading controls, and reboot the system.
New CPU microcode may be available in a BIOS update from your system vendor,
or by installing the devcpu-data package or sysutils/devcpu-data port.
Ensure that the BIOS update or devcpu-data package is dated after 2019-05-14.
If using the package or port the Intel microcode update can be applied at
boot time (only on FreeBSD 12 and later) by adding the following lines to the
system's /boot/loader.conf:
cpu_microcode_load="YES"
cpu_microcode_name="/boot/firmware/intel-ucode.bin"
To automatically load microcode during userland startup (supported on all
FreeBSD versions), add the following to /etc/rc.conf:
microcode_update_enable="YES"
1) To update your vulnerable system via a binary patch:
Systems running a RELEASE version of FreeBSD on the i386 or amd64
platforms can be updated via the freebsd-update(8) utility:
# freebsd-update fetch
# freebsd-update install
Follow additional details under "Mitigation Configuration" below.
2) To update your vulnerable system via a source code patch:
The following patches have been verified to apply to the applicable
FreeBSD release branches.
a) Download the relevant patch from the location below, and verify the
detached PGP signature using your PGP utility.
[FreeBSD 12.0-STABLE]
# fetch https://security.FreeBSD.org/patches/SA-19:07/mds.12-stable.patch
# fetch https://security.FreeBSD.org/patches/SA-19:07/mds.12-stable.patch.asc
# gpg --verify mds.12-stable.patch.asc
[FreeBSD 12.0-RELEASE]
# fetch https://security.FreeBSD.org/patches/SA-19:07/mds.12.0.patch
# fetch https://security.FreeBSD.org/patches/SA-19:07/mds.12.0.patch.asc
# gpg --verify mds.12.0.patch.asc
[FreeBSD 11.3-PRERELEASE]
# fetch https://security.FreeBSD.org/patches/SA-19:07/mds.11-stable.patch
# fetch https://security.FreeBSD.org/patches/SA-19:07/mds.11-stable.patch.asc
# gpg --verify mds.11-stable.patch.asc
[FreeBSD 11.2-RELEASE]
# fetch https://security.FreeBSD.org/patches/SA-19:07/mds.11.2.patch
# fetch https://security.FreeBSD.org/patches/SA-19:07/mds.11.2.patch.asc
# gpg --verify mds.11.2.patch.asc
b) Apply the patch. Execute the following commands as root:
# cd /usr/src
# patch < /path/to/patch
c) Recompile your kernel as described in
<URL:https://www.FreeBSD.org/handbook/kernelconfig.html>.
Mitigation Configuration
Systems with users, processes, or virtual machines in different trust
domains should disable Hyper-Threading by setting the
machdep.hyperthreading_allowed tunable to 0:
# echo machdep.hyperthreading_allowed=0 >> /boot/loader.conf
To activate the MDS mitigation set the hw.mds_disable sysctl. The settings
are:
0 - mitigation disabled
1 - VERW instruction (microcode) mitigation enabled
2 - Software sequence mitigation enabled (not recommended)
3 - Automatic VERW or Software selection
Automatic mode uses the VERW instruction if supported by the CPU / microcode,
or software sequences if not. To enable automatic mode at boot:
# echo hw.mds_disable=3 >> /etc/sysctl.conf
Reboot the system:
# shutdown -r +10min "Security update"
Check the mitigation status:
# sysctl hw.mds_disable_state
hw.mds_disable_state: software Silvermont
VI. Correction details
The following list contains the correction revision numbers for each
affected branch.
Branch/path Revision
- - -------------------------------------------------------------------------
stable/12/ r347567
releng/12.0/ r346594
stable/11/ r347568
releng/11.2/ r347595
- - -------------------------------------------------------------------------
To see which files were modified by a particular revision, run the
following command, replacing NNNNNN with the revision number, on a
machine with Subversion installed:
# svn diff -cNNNNNN --summarize svn://svn.freebsd.org/base
Or visit the following URL, replacing NNNNNN with the revision number:
<URL:https://svnweb.freebsd.org/base?view=revision&revision=NNNNNN>
VII. References
<URL:https://www.intel.com/content/www/us/en/security-center/advisory/intel-sa-00233.html>
<URL:https://www.intel.com/content/www/us/en/architecture-and-technology/mds.html>
The latest revision of this advisory is available at
<URL:https://security.FreeBSD.org/advisories/FreeBSD-SA-19:07.mds.asc>
- -----BEGIN PGP SIGNATURE-----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=pDA1
- -----END PGP SIGNATURE-----
_______________________________________________
freebsd-security-notifications@freebsd.org mailing list
https://lists.freebsd.org/mailman/listinfo/freebsd-security-notifications
To unsubscribe, send any mail to "freebsd-security-notifications-unsubscribe@freebsd.org"
- --------------------------END INCLUDED TEXT--------------------
You have received this e-mail bulletin as a result of your organisation's
registration with AusCERT. The mailing list you are subscribed to is
maintained within your organisation, so if you do not wish to continue
receiving these bulletins you should contact your local IT manager. If
you do not know who that is, please send an email to auscert@auscert.org.au
and we will forward your request to the appropriate person.
NOTE: Third Party Rights
This security bulletin is provided as a service to AusCERT's members. As
AusCERT did not write the document quoted above, AusCERT has had no control
over its content. The decision to follow or act on information or advice
contained in this security bulletin is the responsibility of each user or
organisation, and should be considered in accordance with your organisation's
site policies and procedures. AusCERT takes no responsibility for consequences
which may arise from following or acting on information or advice contained in
this security bulletin.
NOTE: This is only the original release of the security bulletin. It may
not be updated when updates to the original are made. If downloading at
a later date, it is recommended that the bulletin is retrieved directly
from the author's website to ensure that the information is still current.
Contact information for the authors of the original document is included
in the Security Bulletin above. If you have any questions or need further
information, please contact them directly.
Previous advisories and external security bulletins can be retrieved from:
https://www.auscert.org.au/bulletins/
===========================================================================
Australian Computer Emergency Response Team
The University of Queensland
Brisbane
Qld 4072
Internet Email: auscert@auscert.org.au
Facsimile: (07) 3365 7031
Telephone: (07) 3365 4417 (International: +61 7 3365 4417)
AusCERT personnel answer during Queensland business hours
which are GMT+10:00 (AEST).
On call after hours for member emergencies only.
===========================================================================
-----BEGIN PGP SIGNATURE-----
Comment: http://www.auscert.org.au/render.html?it=1967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=yuE8
-----END PGP SIGNATURE-----