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Gentoo Linux Security Advisory                           GLSA 200908-02
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                                            http://security.gentoo.org/
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  Severity: Normal
     Title: BIND: Denial of Service
      Date: August 01, 2009
      Bugs: #279508
        ID: 200908-02

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Synopsis
========

Dynamic Update packets can cause a Denial of Service in the BIND
daemon.

Background
==========

ISC BIND is the Internet Systems Consortium implementation of the
Domain Name System (DNS) protocol.

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

    -------------------------------------------------------------------
     Package       /  Vulnerable  /                         Unaffected
    -------------------------------------------------------------------
  1  net-dns/bind     < 9.4.3_p3                           >= 9.4.3_p3

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

Matthias Urlichs reported that the dns_db_findrdataset() function fails
when the prerequisite section of the dynamic update message contains a
record of type "ANY" and where at least one RRset for this FQDN exists
on the server.

Impact
======

A remote unauthenticated attacker could send a specially crafted
dynamic update message to the BIND daemon (named), leading to a Denial
of Service (daemon crash). This vulnerability affects all primary
(master) servers -- it is not limited to those that are configured to
allow dynamic updates.

Workaround
==========

Configure a firewall that performs Deep Packet Inspection to prevent
nsupdate messages from reaching named. Alternatively, expose only
secondary (slave) servers to untrusted networks.

Resolution
==========

All BIND users should upgrade to the latest version:

    # emerge --sync
    # emerge --ask --oneshot --verbose ">=net-dns/bind-9.4.3_p3"

References
==========

  [ 1 ] CVE-2009-0696
        http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2009-0696
  [ 2 ] ISC advisory
        https://www.isc.org/node/474

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

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

  http://security.gentoo.org/glsa/glsa-200908-02.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 2009 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