Protect yourself against future threats.
-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1
===========================================================================
AUSCERT External Security Bulletin Redistribution
ESB-2005.0385 -- FreeBSD-SA-05:09.htt
information disclosure when using HTT
13 May 2005
===========================================================================
AusCERT Security Bulletin Summary
---------------------------------
Product: kernel
Publisher: FreeBSD
Operating System: FreeBSD prior to 5.4-RELEASE-p1
Impact: Increased Privileges
Access Privileged Data
Access: Existing Account
CVE Names: CAN-2005-0109
Original Bulletin:
ftp://ftp.freebsd.org/pub/FreeBSD/CERT/advisories/FreeBSD-SA-05:09.htt.asc
Comment: This vulnerability affects several FreeBSD versions (including 5.4,
5.3, 4.11 and 4.10). Please see the following advisory for specific
version and patching information.
- --------------------------BEGIN INCLUDED TEXT--------------------
- -----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1
=============================================================================
FreeBSD-SA-05:09.htt Security Advisory
The FreeBSD Project
Topic: information disclosure when using HTT
Category: core
Module: sys
Announced: 2005-05-13
Revised: 2005-05-13
Credits: Colin Percival
Affects: All FreeBSD/i386 and FreeBSD/amd64 releases.
Corrected: 2005-05-13 00:13:00 UTC (RELENG_5, 5.4-STABLE)
2005-05-13 00:13:00 UTC (RELENG_5_4, 5.4-RELEASE-p1)
2005-05-13 00:13:00 UTC (RELENG_5_3, 5.3-RELEASE-p15)
2005-05-13 00:13:00 UTC (RELENG_4, 4.11-STABLE)
2005-05-13 00:13:00 UTC (RELENG_4_11, 4.11-RELEASE-p9)
2005-05-13 00:13:00 UTC (RELENG_4_10, 4.10-RELEASE-p14)
CVE Name: CAN-2005-0109
For general information regarding FreeBSD Security Advisories,
including descriptions of the fields above, security branches, and the
following sections, please visit
<URL:http://www.freebsd.org/security/>.
I. Background
"Hyper-Threading Technology" is the name used for the implementation of
simultaneous multithreading on Intel Pentium 4, Mobile Pentium 4, and
Xeon processors.
II. Problem Description
A security flaw involving operating systems running on Hyper-Threading
Technology processors was has been reported. Complete details are not
available at the time of this writing. However, a workaround has been
issued. It is expected that more details will be available tomorrow, at
which time a revised version of this advisory will be published.
III. Impact
Information may be disclosed to local users, allowing in many cases for
privilege escalation.
IV. Workaround
Systems not using processors with Hyper-Threading support are not
affected by this issue. On systems which are affected, the security
flaw can be eliminated by setting the "machdep.hlt_logical_cpus"
tunable:
# echo "machdep.hlt_logical_cpus=1" >> /boot/loader.conf
The system must be rebooted in order for tunables to take effect.
Use of this workaround is not recommended on "dual-core" systems, as
this workaround will also disable one of the processor cores.
V. Solution
Perform one of the following:
1) Upgrade your vulnerable system to 4-STABLE or 5-STABLE, or to the
RELENG_5_4, RELENG_5_3, RELENG_4_11, or RELENG_4_10 security branch
dated after the correction date.
2) To patch your present system:
The following patches have been verified to apply to FreeBSD 4.10,
4.11, 5.3, and 5.4 systems.
a) Download the relevant patch from the location below and verify the
detached PGP signature using your PGP utility.
[FreeBSD 4.10]
# fetch ftp://ftp.FreeBSD.org/pub/FreeBSD/CERT/patches/SA-05:09/htt410.patch
# fetch ftp://ftp.FreeBSD.org/pub/FreeBSD/CERT/patches/SA-05:09/htt410.patch.asc
[FreeBSD 4.11]
# fetch ftp://ftp.FreeBSD.org/pub/FreeBSD/CERT/patches/SA-05:09/htt411.patch
# fetch ftp://ftp.FreeBSD.org/pub/FreeBSD/CERT/patches/SA-05:09/htt411.patch.asc
[FreeBSD 5.x]
# fetch ftp://ftp.FreeBSD.org/pub/FreeBSD/CERT/patches/SA-05:09/htt5.patch
# fetch ftp://ftp.FreeBSD.org/pub/FreeBSD/CERT/patches/SA-05:09/htt5.patch.asc
b) Apply the patch.
# cd /usr/src
# patch < /path/to/patch
c) Recompile your kernel as described in
<URL:http://www.freebsd.org/handbook/kernelconfig.html> and reboot the
system.
NOTE: For users that are certain that their environment is not affected
by this vulnerability, such as single-user systems, Hyper-Threading
Technology may be re-enabled by setting the tunable
"machdep.hyperthreading_allowed".
VI. Correction details
The following list contains the revision numbers of each file that was
corrected in FreeBSD.
Branch Revision
Path
- - -------------------------------------------------------------------------
RELENG_4
src/sys/i386/i386/mp_machdep.c 1.115.2.23
src/sys/i386/include/cpufunc.h 1.96.2.4
RELENG_4_11
src/UPDATING 1.73.2.91.2.10
src/sys/conf/newvers.sh 1.44.2.39.2.13
src/sys/i386/i386/mp_machdep.c 1.115.2.22.2.1
src/sys/i386/include/cpufunc.h 1.96.2.3.12.1
RELENG_4_10
src/UPDATING 1.73.2.90.2.15
src/sys/conf/newvers.sh 1.44.2.34.2.16
src/sys/i386/i386/mp_machdep.c 1.115.2.20.2.1
src/sys/i386/include/cpufunc.h 1.96.2.3.10.1
RELENG_5
src/sys/amd64/amd64/mp_machdep.c 1.242.2.11
src/sys/amd64/include/cpufunc.h 1.145.2.1
src/sys/i386/i386/mp_machdep.c 1.235.2.10
src/sys/i386/include/cpufunc.h 1.142.2.1
RELENG_5_4
src/UPDATING 1.342.2.24.2.10
src/sys/amd64/amd64/mp_machdep.c 1.242.2.7.2.4
src/sys/amd64/include/cpufunc.h http://www.securityfocus.com/bid/12724 1.145.6.1
src/sys/conf/newvers.sh 1.62.2.18.2.6
src/sys/i386/i386/mp_machdep.c 1.235.2.6.2.3
src/sys/i386/include/cpufunc.h 1.142.6.1
RELENG_5_3
src/UPDATING 1.342.2.13.2.18
src/sys/amd64/amd64/mp_machdep.c 1.242.2.2.2.2
src/sys/amd64/include/cpufunc.h 1.145.4.1
src/sys/conf/newvers.sh 1.62.2.15.2.20
src/sys/i386/i386/mp_machdep.c 1.235.2.3.2.2
src/sys/i386/include/cpufunc.h 1.142.4.1
- - -------------------------------------------------------------------------
VII. References
http://www.daemonology.net/hyperthreading-considered-harmful/
The latest revision of this advisory is available at
ftp://ftp.freebsd.org/pub/FreeBSD/CERT/advisories/FreeBSD-SA-05:09.htt.asc
- -----BEGIN PGP SIGNATURE-----
iD8DBQFCg/RTFdaIBMps37IRAsPSAJ4tjVMklYy1N4QOWlDyVEAORkz+hACgmwMB
vDnIfC+nobvQbb6onu7XkBc=
=Yawq
- -----END PGP SIGNATURE-----
- --------------------------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:
http://www.auscert.org.au/render.html?cid=1980
If you believe that your computer system has been compromised or attacked in
any way, we encourage you to let us know by completing the secure National IT
Incident Reporting Form at:
http://www.auscert.org.au/render.html?it=3192
===========================================================================
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
iQCVAwUBQoRLRih9+71yA2DNAQLS4AQAmVAtqqKiRsl/L9Uyp4lsrw2UOb8Cv87z
vdZY+JNEqMY8qZrC+rrSrDq2UW40TsccYwtfegZOdf6qhMVt2/XjGhj/h5sBonAh
6ZPwJa2NVmxJbypWMOg6sHjv8PZFEwaqSuM0GIAMlt1HMBppbbsZAgUDw1g4U/H3
m7cIvpsn0dQ=
=nQ0C
-----END PGP SIGNATURE-----