Gentoo 2512 Published by

A: Dnsmasq security update has been released for Gentoo Linux.



- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
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=@ 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-