Protect yourself against future threats.
-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1
===========================================================================
AUSCERT External Security Bulletin Redistribution
ESB-2009.0556 -- [FreeBSD]
ntpd: Execute Arbitrary Code
11 June 2009
===========================================================================
AusCERT Security Bulletin Summary
---------------------------------
Product: ntpd
Publisher: FreeBSD
Operating System: FreeBSD
Impact: Execute Arbitrary Code/Commands
Denial of Service
Access: Remote/Unauthenticated
CVE Names: CVE-2009-1252
Ref: ESB-2009.0475
ESB-2009.0484
Original Bulletin:
ftp://ftp.freebsd.org/pub/FreeBSD/CERT/advisories/FreeBSD-SA-09:11.ntpd.asc
- --------------------------BEGIN INCLUDED TEXT--------------------
- -----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1
=============================================================================
FreeBSD-SA-09:11.ntpd Security Advisory
The FreeBSD Project
Topic: ntpd stack-based buffer-overflow vulnerability
Category: contrib
Module: ntpd
Announced: 2009-06-10
Credits: Chris Ries
Affects: All supported versions of FreeBSD.
Corrected: 2009-06-10 10:31:11 UTC (RELENG_7, 7.2-STABLE)
2009-06-10 10:31:11 UTC (RELENG_7_2, 7.2-RELEASE-p1)
2009-06-10 10:31:11 UTC (RELENG_7_1, 7.1-RELEASE-p6)
2009-06-10 10:31:11 UTC (RELENG_6, 6.4-STABLE)
2009-06-10 10:31:11 UTC (RELENG_6_4, 6.4-RELEASE-p5)
2009-06-10 10:31:11 UTC (RELENG_6_3, 6.3-RELEASE-p11)
CVE Name: CVE-2009-1252
For general information regarding FreeBSD Security Advisories,
including descriptions of the fields above, security branches, and the
following sections, please visit <URL:http://security.FreeBSD.org/>.
I. Background
The ntpd(8) daemon is an implementation of the Network Time Protocol (NTP)
used to synchronize the time of a computer system to a reference time
source.
Autokey is a security model for authenticating Network Time Protocol
(NTP) servers to clients, using public key cryptography.
II. Problem Description
The ntpd(8) daemon is prone to a stack-based buffer-overflow when it is
configured to use the 'autokey' security model.
III. Impact
This issue could be exploited to execute arbitrary code in the context of
the service daemon, or crash the service daemon, causing denial-of-service
conditions.
IV. Workaround
Use IP based restrictions in ntpd(8) itself or in IP firewalls to
restrict which systems can send NTP packets to ntpd(8).
Note that systems will only be affected if they have the "autokey" option
set in /etc/ntp.conf; FreeBSD does not ship with a default ntp.conf file,
so will not be affected unless this option has been explicitly enabled by
the system administrator.
V. Solution
Perform one of the following:
1) Upgrade your vulnerable system to 6-STABLE, or 7-STABLE, or to the
RELENG_7_2, RELENG_7_1, RELENG_6_4, or RELENG_6_3 security branch
dated after the correction date.
2) To patch your present system:
The following patches have been verified to apply to FreeBSD 6.3, 6.4,
7.1, and 7.2 systems.
a) Download the relevant patch from the location below, and verify the
detached PGP signature using your PGP utility.
[FreeBSD 6.3]
# fetch http://security.FreeBSD.org/patches/SA-09:11/ntpd63.patch
# fetch http://security.FreeBSD.org/patches/SA-09:11/ntpd63.patch.asc
[FreeBSD 6.4 and 7.x]
# fetch http://security.FreeBSD.org/patches/SA-09:11/ntpd.patch
# fetch http://security.FreeBSD.org/patches/SA-09:11/ntpd.patch.asc
b) Execute the following commands as root:
# cd /usr/src
# patch < /path/to/patch
# cd /usr/src/usr.sbin/ntp/ntpd
# make obj && make depend && make && make install
# /etc/rc.d/ntpd restart
VI. Correction details
The following list contains the revision numbers of each file that was
corrected in FreeBSD.
CVS:
Branch Revision
Path
- - -------------------------------------------------------------------------
RELENG_6
src/contrib/ntp/ntpd/ntp_crypto.c 1.1.1.3.8.3
RELENG_6_4
src/UPDATING 1.416.2.40.2.9
src/sys/conf/newvers.sh 1.69.2.18.2.11
src/contrib/ntp/ntpd/ntp_crypto.c 1.1.1.3.8.1.2.2
RELENG_6_3
src/UPDATING 1.416.2.37.2.16
src/sys/conf/newvers.sh 1.69.2.15.2.15
src/contrib/ntp/ntpd/ntp_crypto.c 1.1.1.3.20.2
RELENG_7
src/contrib/ntp/ntpd/ntp_crypto.c 1.1.1.3.18.3
RELENG_7_2
src/UPDATING 1.507.2.23.2.4
src/sys/conf/newvers.sh 1.72.2.11.2.5
src/contrib/ntp/ntpd/ntp_crypto.c 1.1.1.3.18.2.2.1
RELENG_7_1
src/UPDATING 1.507.2.13.2.9
src/sys/conf/newvers.sh 1.72.2.9.2.10
src/contrib/ntp/ntpd/ntp_crypto.c 1.1.1.3.18.1.2.2
- - -------------------------------------------------------------------------
Subversion:
Branch/path Revision
- - -------------------------------------------------------------------------
stable/6/ r193893
releng/6.4/ r193893
releng/6.3/ r193893
stable/7/ r193893
releng/7.2/ r193893
releng/7.1/ r193893
- - -------------------------------------------------------------------------
VII. References
http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2009-1252
The latest revision of this advisory is available at
http://security.FreeBSD.org/advisories/FreeBSD-SA-09:11.ntpd.asc
- -----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.9 (FreeBSD)
iEYEARECAAYFAkovjOwACgkQFdaIBMps37KRpwCfaQF9q8KhElv6LqgFv3DX2h9c
hbEAn2Q0X8Qv8r5OySnhlAw2pMxlxkXK
=Mh2u
- -----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
iD8DBQFKMIV7NVH5XJJInbgRAtfBAJ9u0Ndci42pEBwWkp04FCI1VgddtgCgguf1
q+ZeQB0d2xgbQQulCWj4bxw=
=AwBe
-----END PGP SIGNATURE-----