This is an OpenPGP/MIME signed message (RFC 4880 and 3156)
--osq7MUwQWQIi8o4NbSqZvqhYxeOdxOXc0
Content-Type: multipart/mixed;
 boundary="3vNVbzhoVBWHztk8Jd1p32kaCht1fNnC8";
 protected-headers="v1"
From: Thomas Deutschmann <whissi@gentoo.org>
Reply-To: security@gentoo.org
To: gentoo-announce@lists.gentoo.org
Message-ID: <59874d3e-2539-ac9e-7460-796142e1e306@gentoo.org>
Subject: [ GLSA 202105-20 ] Dnsmasq: DNS cache poisoning

--3vNVbzhoVBWHztk8Jd1p32kaCht1fNnC8
Content-Type: text/plain; charset=utf-8; format=flowed
Content-Language: en-U
Content-Transfer-Encoding: quoted-printable

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Gentoo Linux Security Advisory                           GLSA 202105-20
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
                                            https://security.gentoo.org/
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

  Severity: Low
     Title: Dnsmasq: DNS cache poisoning
      Date: May 26, 2021
      Bugs: #782130
        ID: 202105-20

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

Synopsis
========

Use of insufficient randomness in Dnsmasq might lead to DNS Cache
Poisoning.

Background
==========

Dnsmasq is a lightweight and easily-configurable DNS forwarder and DHCP
server.

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

     -------------------------------------------------------------------
      Package              /     Vulnerable     /            Unaffected
     -------------------------------------------------------------------
   1  net-dns/dnsmasq               < 2.85                     >= 2.85

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

It was discovered that Dnsmasq, when configured with
--server=<address>@<interface> or similar (e.g. through dbus),
configured a fixed UDP port for all outgoing queries to the specified
upstream DNS server.

Impact
======

An attacker, by sending malicious crafted DNS responses, could perform
a DNS Cache Poisoning attack.

Workaround
==========

There is no known workaround at this time.

Resolution
==========

All Dnsmasq users should upgrade to the latest version:

   # emerge --sync
   # emerge --ask --oneshot --verbose ">=net-dns/dnsmasq-2.85"

References
==========

[ 1 ] CVE-2021-3448
       https://nvd.nist.gov/vuln/detail/CVE-2021-3448

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

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

  https://security.gentoo.org/glsa/202105-20

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@gentoo.org or alternatively, you may file a bug at
https://bugs.gentoo.org.

License
=======

Copyright 2021 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.

https://creativecommons.org/licenses/by-sa/2.5


--3vNVbzhoVBWHztk8Jd1p32kaCht1fNnC8--

--osq7MUwQWQIi8o4NbSqZvqhYxeOdxOXc0
Content-Type: application/pgp-signature; name="OpenPGP_signature.asc"
Content-Description: OpenPGP digital signature
Content-Disposition: attachment; filename="OpenPGP_signature"

-----BEGIN PGP SIGNATURE-----

wsB5BAABCAAjFiEEExKRzo+LDXJgXHuURObr3Jv2BVkFAmCuDF8FAwAAAAAACgkQRObr3Jv2BVn5
Cgf/SL+0QLI+9+1tq+eqNRyCw3rfsc99LYnHWYuvNG7shNOekBwnC11ri9th1hksqvxUrTWehMRa
RpO978SwJy6dp+NUv5QNUx87mYKwizymkJ7kpfk+NreYtrLcQJu4ynStZnWkGZrhFPt08trqmiKZ
HcaCyi8ZAvqpZOwEOv+ygyK1OOBta6YvNUg+3tRcH8M7LFK/eIsMW9S8icPIgaIJ9RlBPru/6mii
MJ5jkklIgEw4QIG4Y+Oj6PaQbbrpK67rU2Pic6Op04rCNBTLeu+Xf2WcAOaU/XLtOXZflMKxppsN
MsRghERfanolFgxNfRoiN8Aq43Q5liU8STOluW8yiQ==
=hd7t
-----END PGP SIGNATURE-----

--osq7MUwQWQIi8o4NbSqZvqhYxeOdxOXc0--