Protect yourself against future threats.
-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA256
===========================================================================
AUSCERT External Security Bulletin Redistribution
ESB-2020.0327
kernel stack data disclosure
30 January 2020
===========================================================================
AusCERT Security Bulletin Summary
---------------------------------
Product: thrmisc
Publisher: FreeBSD
Operating System: FreeBSD
UNIX variants (UNIX, Linux, OSX)
Impact/Access: Read-only Data Access -- Existing Account
Reduced Security -- Existing Account
Resolution: Patch/Upgrade
CVE Names: CVE-2019-15875
Original Bulletin:
https://security.freebsd.org/advisories/FreeBSD-SA-20:03.thrmisc.asc
Comment: This advisory references vulnerabilities in the Linux kernel that
also affect distributions other than FreeBSD. It is recommended that
administrators running Linux check for an updated version of the
kernel for their system.
- --------------------------BEGIN INCLUDED TEXT--------------------
- -----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA512
=============================================================================
FreeBSD-SA-20:03.thrmisc Security Advisory
The FreeBSD Project
Topic: kernel stack data disclosure
Category: core
Module: kernel
Announced: 2020-01-28
Credits: Ilja Van Sprundel
Affects: All supported versions of FreeBSD.
Corrected: 2019-11-15 16:40:10 UTC (stable/12, 12.1-STABLE)
2020-01-28 18:57:45 UTC (releng/12.1, 12.1-RELEASE-p2)
2020-01-28 18:57:45 UTC (releng/12.0, 12.0-RELEASE-p13)
2019-11-15 16:40:55 UTC (stable/11, 11.3-STABLE)
2020-01-28 18:57:45 UTC (releng/11.3, 11.3-RELEASE-p6)
CVE Name: CVE-2019-15875
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/>.
I. Background
The kernel can create a core dump file when a process crashes that contains
process state, for debugging.
II. Problem Description
Due to incorrect initialization of a stack data structure, up to 20 bytes of
kernel data stored previously stored on the stack will be exposed to a
crashing user process.
III. Impact
Sensitive kernel data may be disclosed.
IV. Workaround
Core dumps may be disabled by setting the kern.coredump sysctl to 0.
See sysctl(8) and sysctl.conf(5).
V. Solution
Upgrade your vulnerable system to a supported FreeBSD stable or
release / security branch (releng) dated after the correction date,
and reboot.
Perform one of the following:
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
# shutdown -r +10min "Rebooting for a security update"
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.
# fetch https://security.FreeBSD.org/patches/SA-20:03/thrmisc.patch
# fetch https://security.FreeBSD.org/patches/SA-20:03/thrmisc.patch.asc
# gpg --verify thrmisc.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> and reboot the
system.
VI. Correction details
The following list contains the correction revision numbers for each
affected branch.
Branch/path Revision
- - -------------------------------------------------------------------------
stable/12/ r354734
releng/12.1/ r357219
releng/12.0/ r357219
stable/11/ r354735
releng/11.3/ r357219
- - -------------------------------------------------------------------------
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://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2019-15875>
The latest revision of this advisory is available at
<URL:https://security.FreeBSD.org/advisories/FreeBSD-SA-20:03.thrmisc.asc>
- -----BEGIN PGP SIGNATURE-----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=3mdJ
- -----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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=J25P
-----END PGP SIGNATURE-----