FreeBSD Security Advisory FreeBSD-SA-10:02.ntpd
FreeBSD Security Advisories
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=============================================================================
FreeBSD-SA-10:02.ntpd Security Advisory
The FreeBSD Project
Topic: ntpd mode 7 denial of service
Category: contrib
Module: ntpd
Announced: 2010-01-06
Affects: All supported versions of FreeBSD.
Corrected: 2010-01-06 21:45:30 UTC (RELENG_8, 8.0-STABLE)
2010-01-06 21:45:30 UTC (RELENG_8_0, 8.0-RELEASE-p2)
2010-01-06 21:45:30 UTC (RELENG_7, 7.2-STABLE)
2010-01-06 21:45:30 UTC (RELENG_7_2, 7.2-RELEASE-p6)
2010-01-06 21:45:30 UTC (RELENG_7_1, 7.1-RELEASE-p10)
2010-01-06 21:45:30 UTC (RELENG_6, 6.4-STABLE)
2010-01-06 21:45:30 UTC (RELENG_6_4, 6.4-RELEASE-p9)
2010-01-06 21:45:30 UTC (RELENG_6_3, 6.3-RELEASE-p15)
CVE Name: CVE-2009-3563
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.
II. Problem Description
If ntpd receives a mode 7 (MODE_PRIVATE) request or error response
from a source address not listed in either a 'restrict ... noquery'
or a 'restrict ... ignore' section it will log the even and send
a mode 7 error response.
III. Impact
If an attacker can spoof such a packet from a source IP of an affected
ntpd to the same or a different affected ntpd, the host(s) will endlessly
send error responses to each other and log each event, consuming network
bandwidth, CPU and possibly disk space.
IV. Workaround
Proper filtering of mode 7 NTP packets by a firewall can limit the
number of systems used to attack your resources.
V. Solution
Perform one of the following:
1) Upgrade your vulnerable system to 6-STABLE, 7-STABLE or 8-STABLE,
or to the RELENG_8_0, 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, 7.2, and 8.0 systems.
a) Download the relevant patch from the location below, and verify the
detached PGP signature using your PGP utility.
# fetch http://security.FreeBSD.org/patches/SA-10:02/ntpd.patch
# fetch http://security.FreeBSD.org/patches/SA-10:02/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_request.c 1.1.1.4.8.2
RELENG_6_4
src/UPDATING 1.416.2.40.2.13
src/sys/conf/newvers.sh 1.69.2.18.2.15
src/contrib/ntp/ntpd/ntp_request.c 1.1.1.4.8.1.2.1
RELENG_6_3
src/UPDATING 1.416.2.37.2.20
src/sys/conf/newvers.sh 1.69.2.15.2.19
src/contrib/ntp/ntpd/ntp_request.c 1.1.1.4.20.1
RELENG_7
src/contrib/ntp/ntpd/ntp_request.c 1.1.1.4.18.2
RELENG_7_2
src/UPDATING 1.507.2.23.2.9
src/sys/conf/newvers.sh 1.72.2.11.2.10
src/contrib/ntp/ntpd/ntp_request.c 1.1.1.4.18.1.4.1
RELENG_7_1
src/UPDATING 1.507.2.13.2.13
src/sys/conf/newvers.sh 1.72.2.9.2.14
src/contrib/ntp/ntpd/ntp_request.c 1.1.1.4.18.1.2.1
RELENG_8
src/contrib/ntp/ntpd/ntp_request.c 1.2.2.1
RELENG_8_0
src/UPDATING 1.632.2.7.2.5
src/sys/conf/newvers.sh 1.83.2.6.2.5
src/contrib/ntp/ntpd/ntp_request.c 1.2.4.1
- -------------------------------------------------------------------------
Subversion:
Branch/path Revision
- -------------------------------------------------------------------------
stable/6/ r201679
releng/6.4/ r201679
releng/6.3/ r201679
stable/7/ r201679
releng/7.2/ r201679
releng/7.1/ r201679
stable/8/ r201679
releng/8.0/ r201679
head/ r200576
- -------------------------------------------------------------------------
VII. References
http://support.ntp.org/bin/view/Main/SecurityNotice#DoS_attack_from_certain_NTP_mode
https://support.ntp.org/bugs/show_bug.cgi?id=1331
http://www.kb.cert.org/vuls/id/568372
http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2009-3563
The latest revision of this advisory is available at
http://security.FreeBSD.org/advisories/FreeBSD-SA-10:02.ntpd.asc
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Harlan Stenn
> II. Problem Description
>
> If ntpd receives a mode 7 (MODE_PRIVATE) request or error response
it's a *malformed* mode 7 request, or an error response ...
Normal mode 7 requests have been (and are) handled just fine and are not
logged by default.
> from a source address not listed in either a 'restrict ... noquery'
> or a 'restrict ... ignore' section it will log the even and send
s/even/event/
> a mode 7 error response.
> IV. Workaround
>
> Proper filtering of mode 7 NTP packets by a firewall can limit the
> number of systems used to attack your resources.
If you can find a firewall that will do this, please lemme know.
We haven't found any.
Thanks...
H
jhell
With the directions in this message you will receive the following error:
make: don't know how to make
/usr/obj/usr/src/usr.sbin/ntp/ntpd/../libparse/libparse.a. Stop
Should state (minimal)
# cd /usr/src
# patch < /path/to/patch
# cd /usr/src/usr.sbin/ntp
# make obj && make depend && make && make install
# /etc/rc.d/ntpd restart
Please note this for next time. This is the second time I have counted
that this has been overlooked.
On Wed, 6 Jan 2010 17:55, security-advisories@ wrote:
> ---------------------------- PGP Command Output ----------------------------
> gpg: Signature made Wed Jan 6 17:32:00 2010 EST using DSA key ID CA6CDFB2
> gpg: Good signature from "FreeBSD Security Officer <security...@FreeBSD.org>"
> ----------- Begin PGP Signed Message Verified 2010-01-07 03:50:19 ----------
>
> =============================================================================
> FreeBSD-SA-10:02.ntpd Security Advisory
> The FreeBSD Project
>
> Topic: ntpd mode 7 denial of service
>
> Category: contrib
> Module: ntpd
> Announced: 2010-01-06
> Affects: All supported versions of FreeBSD.
> Corrected: 2010-01-06 21:45:30 UTC (RELENG_8, 8.0-STABLE)
> 2010-01-06 21:45:30 UTC (RELENG_8_0, 8.0-RELEASE-p2)
> 2010-01-06 21:45:30 UTC (RELENG_7, 7.2-STABLE)
> 2010-01-06 21:45:30 UTC (RELENG_7_2, 7.2-RELEASE-p6)
> 2010-01-06 21:45:30 UTC (RELENG_7_1, 7.1-RELEASE-p10)
> 2010-01-06 21:45:30 UTC (RELENG_6, 6.4-STABLE)
> 2010-01-06 21:45:30 UTC (RELENG_6_4, 6.4-RELEASE-p9)
> 2010-01-06 21:45:30 UTC (RELENG_6_3, 6.3-RELEASE-p15)
> CVE Name: CVE-2009-3563
>
> 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.
>
> II. Problem Description
>
> If ntpd receives a mode 7 (MODE_PRIVATE) request or error response
> from a source address not listed in either a 'restrict ... noquery'
> or a 'restrict ... ignore' section it will log the even and send
> a mode 7 error response.
>
> III. Impact
>
> If an attacker can spoof such a packet from a source IP of an affected
> ntpd to the same or a different affected ntpd, the host(s) will endlessly
> send error responses to each other and log each event, consuming network
> bandwidth, CPU and possibly disk space.
>
> IV. Workaround
>
> Proper filtering of mode 7 NTP packets by a firewall can limit the
> number of systems used to attack your resources.
>
> V. Solution
>
> Perform one of the following:
>
> 1) Upgrade your vulnerable system to 6-STABLE, 7-STABLE or 8-STABLE,
> or to the RELENG_8_0, 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, 7.2, and 8.0 systems.
>
> a) Download the relevant patch from the location below, and verify the
> detached PGP signature using your PGP utility.
>
> # fetch http://security.FreeBSD.org/patches/SA-10:02/ntpd.patch
> # fetch http://security.FreeBSD.org/patches/SA-10:02/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
> Subversion:
>
> Branch/path Revision
> -------------------------------------------------------------------------
> stable/6/ r201679
> releng/6.4/ r201679
> releng/6.3/ r201679
> stable/7/ r201679
> releng/7.2/ r201679
> releng/7.1/ r201679
> stable/8/ r201679
> releng/8.0/ r201679
> head/ r200576
> -------------------------------------------------------------------------
>
> VII. References
>
> http://support.ntp.org/bin/view/Main/SecurityNotice#DoS_attack_from_certain_NTP_mode
> https://support.ntp.org/bugs/show_bug.cgi?id=1331
> http://www.kb.cert.org/vuls/id/568372
> http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2009-3563
>
> The latest revision of this advisory is available at
> http://security.FreeBSD.org/advisories/FreeBSD-SA-10:02.ntpd.asc
>
> ------------ End PGP Signed Message Verified 2010-01-07 03:50:19 -----------
>
--
Thu Jan 7 03:50:18 2010
jhell
Roland Smith
the build procedure for ntpd failed;
# cd /usr/src/usr.sbin/ntp/ntpd
# make obj && make depend && make && make install
don't know how to make /usr/obj/usr/src/usr.sbin/ntp/ntpd/../libparse/libparse.a. Stop
So I changed the procedure as follows, to make it work;
# cd /usr/src/usr.sbin/ntp/ntpd
# make obj && make depend
# cd ../libparse/
# make obj && make depend && make
# cd ../libopts/
# make obj && make depend && make
# cd ../libntp/
# make obj && make depend && make
# cd ../ntpd
# make && make install
# /etc/rc.d/ntpd restart
I do not know what the cause of this problem is, but I suspect a Makefile
somewhere. If more people report this, maybe an errata notice should be
posted?
Hope this helps.
Roland
--
R.F.Smith http://www.xs4all.nl/~rsmith/
[plain text _non-HTML_ PGP/GnuPG encrypted/signed email much appreciated]
pgp: 1A2B 477F 9970 BA3C 2914 B7CE 1277 EFB0 C321 A725 (KeyID: C321A725)
Roberto Nunnari
> After updating the source to 8.0-RELEASE-p2 (according to /usr/src/UPDATING),
> the build procedure for ntpd failed;
>
> # cd /usr/src/usr.sbin/ntp/ntpd
> # make obj && make depend && make && make install
> don't know how to make /usr/obj/usr/src/usr.sbin/ntp/ntpd/../libparse/libparse.a. Stop
>
> So I changed the procedure as follows, to make it work;
>
> # cd /usr/src/usr.sbin/ntp/ntpd
> # make obj && make depend
> # cd ../libparse/
> # make obj && make depend && make
> # cd ../libopts/
> # make obj && make depend && make
> # cd ../libntp/
> # make obj && make depend && make
> # cd ../ntpd
> # make && make install
> # /etc/rc.d/ntpd restart
>
> I do not know what the cause of this problem is, but I suspect a Makefile
> somewhere. If more people report this, maybe an errata notice should be
> posted?
>
> Hope this helps.
>
> Roland
I may be wrong (please correct me if I'm wrong), but I believe
the problem comes from wheater you have previously 'make buildworld'
and deleted (or not) /usr/obj/*
If you have the results of a previous 'make buildworld' under /usr/obj/
then the original post procedure works fine, while if you don't
it will fail. In that case, just cd .. and repeat the above steps.
Miroslav Lachman
> After updating the source to 8.0-RELEASE-p2 (according to /usr/src/UPDATING),
> the build procedure for ntpd failed;
>
> # cd /usr/src/usr.sbin/ntp/ntpd
> don't know how to make /usr/obj/usr/src/usr.sbin/ntp/ntpd/../libparse/libparse.a. Stop
Try
cd /usr/src/usr.sbin/ntp
instead of
cd /usr/src/usr.sbin/ntp/ntpd
Miroslav Lachman