Gentoo Archives: gentoo-announce

From: Tobias Heinlein <keytoaster@g.o>
To: gentoo-announce@g.o
Subject: [gentoo-announce] [ GLSA 201401-08 ] NTP: Traffic amplification
Date: Thu, 16 Jan 2014 23:36:37
Message-Id: 52D86C53.6040908@gentoo.org
-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA256

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Gentoo Linux Security Advisory                           GLSA 201401-08
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
                                            http://security.gentoo.org/
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

 Severity: Normal
    Title: NTP: Traffic amplification
     Date: January 16, 2014
     Bugs: #496776
       ID: 201401-08

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

Synopsis
========

NTP can be abused to amplify Denial of Service attack traffic.

Background
==========

NTP is a protocol designed to synchronize the clocks of computers over
a network. The net-misc/ntp package contains the official reference
implementation by the NTP Project.

Affected packages
=================

    -------------------------------------------------------------------
     Package              /     Vulnerable     /            Unaffected
    -------------------------------------------------------------------
  1  net-misc/ntp              < 4.2.6_p5-r10         >= 4.2.6_p5-r10

Description
===========

ntpd is susceptible to a reflected Denial of Service attack. Please
review the CVE identifiers and references below for details.

Impact
======

An unauthenticated remote attacker may conduct a distributed reflective
Denial of Service attack on another user via a vulnerable NTP server.

Workaround
==========

We modified the default ntp configuration in =net-misc/ntp-4.2.6_p5-r10
and added "noquery" to the default restriction which disallows anyone
to query the ntpd status, including "monlist".

If you use a non-default configuration, and provide a ntp service to
untrusted networks, we highly recommend you to revise your
configuration to disable mode 6 and 7 queries for any untrusted
(public) network.

You can always enable these queries for specific trusted networks. For
more details please see the "Access Control Support" chapter in the
ntp.conf(5) man page.

Resolution
==========

All NTP users should upgrade to the latest version:

  # emerge --sync
  # emerge --ask --oneshot --verbose ">=net-misc/ntp-4.2.6_p5-r10"

Note that the updated package contains a modified default configuration
only. You may need to modify your configuration further.

References
==========

[ 1 ] CVE-2013-5211
      http://nvd.nist.gov/nvd.cfm?cvename=CVE-2013-5211
[ 2 ] VU#348126
      http://www.kb.cert.org/vuls/id/348126

Availability
============

This GLSA and any updates to it are available for viewing at
the Gentoo Security Website:

 http://security.gentoo.org/glsa/glsa-201401-08.xml

Concerns?
=========

Security is a primary focus of Gentoo Linux and ensuring the
confidentiality and security of our users' machines is of utmost
importance to us. Any security concerns should be addressed to
security@g.o or alternatively, you may file a bug at
https://bugs.gentoo.org.

License
=======

Copyright 2014 Gentoo Foundation, Inc; referenced text
belongs to its owner(s).

The contents of this document are licensed under the
Creative Commons - Attribution / Share Alike license.

http://creativecommons.org/licenses/by-sa/2.5
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v2.0.22 (GNU/Linux)
Comment: Using GnuPG with Thunderbird - http://www.enigmail.net/
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=rXbW
-----END PGP SIGNATURE-----