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NetBSD Security Advisory 2015-003: NTPd multiple vulnerabilities (CVE-2014-929[3-6])

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                NetBSD Security Advisory 2015-003
                =================================

Topic:          NTPd multiple vulnerabilities (CVE-2014-929[3-6])


Version:        NetBSD-current:         source prior to Dec 19, 2014
                NetBSD 7 Beta:          source prior to Dec 23, 2014
                NetBSD 6.1:             affected
                NetBSD 6.0:             affected
                NetBSD 5.2:             affected
                NetBSD 5.1:             affected
                pkgsrc (net/ntp4):      affected

Severity:       Denial of Service

Fixed:          NetBSD-current:         Dec 19, 2014
                NetBSD-7 branch:        Dec 28, 2014
                NetBSD-6 branch:        Dec 29, 2014
                NetBSD-6-1 branch:      Dec 29, 2014
                NetBSD-6-0 branch:      Dec 29, 2014
                NetBSD-5 branch:        Jan 08, 2015
                NetBSD-5-2 branch:      Jan 08, 2015
                NetBSD-5-1 branch:      Jan 08, 2015
                pkgsrc:                 Dec 28, 2014

Please note that NetBSD releases prior to 5.1 are no longer supported.
It is recommended that all users upgrade to a supported release.


Abstract
========

Multiple issues have been discovered with the Network Time Daemon and
related programs, and published by NTP.org and US-CERT on December 19th.
Systems that use ntpd, should upgrade to the latest version to avoid
remote DoS attacks, and on NetBSD 5 since there is no Stack Smashing
Protection the possibility of a remote compromise.


Technical Details
=================

Four different advisories have been published addressing different issues:

CVE-2014-9293: Weak Default Key: When no key is set in the configuration
               ntpd(8) will generate keys with very few bits of entropy.
CVE-2014-9294: The random number generator in ntp-keygen(8) is using a seed
               with very few bits of entropy to generate symmetric keys.
CVE-2014-9295: With autokey authentication ("crypto pw" configuration
               directive), a remote user can construct a network packet
               that will cause stack overflow.
CVE-2014-9296: The ntpd receive() function in ntp_proto.c is missing a
               return on error.


Solutions and Workarounds
=========================

Aside from replacing the daemon, we advise administrators of systems
that use ntpd(8) to firewall ports tcp/123 and udp/123 so that packets
from unknown hosts are rejected.

Get a new ntpd binary:

VERS being your NetBSD version
DATE being a build date past the fix date for your version
ARCH being your machine architecture
ftp -o /var/tmp/base.tgz
http://nyftp.netbsd.org/pub/NetBSD-daily/VERS/DATE/ARCH/binary/sets/base.tgz
cd /
tar xzpf /var/tmp/base.tgz ./usr/sbin/ntpd

Since ntpd was updated to the current upstream version, the changes touch
a lot of files; if you want to update from source, updating the entire
src tree is recommended.

Another option to deal with the vulnerability is to install the updated
ntp4 package and use the package ntpd until the system can be updated.


Thanks To
=========

Thanks to Harlan Stenn for alerting us to the upcoming NTP release,
Christos Zoulas for upgrading the package and constructing initial
patches, Jeff Rizzo for updating -7, Soren Jacobsen for updating -6,
and Havard Eidnes for updating -5.


Revision History
================

        2015-03-17      Initial release


More Information
================

Advisories may be updated as new information becomes available.
The most recent version of this advisory (PGP signed) can be found at

http://ftp.NetBSD.org/pub/NetBSD/security/advisories/NetBSD-SA2015-003.txt.asc

Information about NetBSD and NetBSD security can be found at
http://www.NetBSD.org/ and http://www.NetBSD.org/Security/ .


Copyright 2015, The NetBSD Foundation, Inc.  All Rights Reserved.
Redistribution permitted only in full, unmodified form.

$NetBSD: NetBSD-SA2015-003.txt,v 1.1 2015/03/17 06:58:44 spz Exp $

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