Gentoo: Dnsmasq Multiple vulnerabilities
Posted by Benjamin D. Thomas   
Gentoo =3D=3D=3D=3D=3D=3D=3D=3D Multiple vulnerabilities in Dnsmasq might result in the remote execution of arbitrary code, or a Denial of Service.
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Gentoo Linux Security Advisory                           GLSA 200909-19
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                                            http://security.gentoo.org/
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  Severity: Normal
     Title: Dnsmasq: Multiple vulnerabilities
      Date: September 20, 2009
      Bugs: #282653
        ID: 200909-19

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Synopsis
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Multiple vulnerabilities in Dnsmasq might result in the remote
execution of arbitrary code, or a Denial of Service.

Background
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Dnsmasq is a lightweight, easy to configure DNS forwarder and DHCP
server. It includes support for Trivial FTP (TFTP).

Affected packages
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    -------------------------------------------------------------------
     Package          /  Vulnerable  /                      Unaffected
    -------------------------------------------------------------------
  1  net-dns/dnsmasq       < 2.5.0                            >=3D 2.5.0

Description
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Multiple vulnerabilities have been reported in the TFTP functionality
included in Dnsmasq:

* Pablo Jorge and Alberto Solino discovered a heap-based buffer
  overflow (CVE-2009-2957).

* An anonymous researcher reported a NULL pointer reference
  (CVE-2009-2958).

Impact
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A remote attacker in the local network could exploit these
vulnerabilities by sending specially crafted TFTP requests to a machine
running Dnsmasq, possibly resulting in the remote execution of
arbitrary code with the privileges of the user running the daemon, or a
Denial of Service. NOTE: The TFTP server is not enabled by default.

Workaround
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You can disable the TFTP server either at buildtime by not enabling the
"tftp" USE flag, or at runtime. Make sure "--enable-tftp" is not set in
the DNSMASQ_OPTS variable in the /etc/conf.d/dnsmasq file and
"enable-tftp" is not set in /etc/dnsmasq.conf, either of which would
enable TFTP support if it is compiled in.

Resolution
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All Dnsmasq users should upgrade to the latest version:

    # emerge --sync
    # emerge --ask --oneshot --verbose =3Dnet-dns/dnsmasq-2.5.0

References
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  [ 1 ] CVE-2009-2957
        http://cve.mitre.org/cgi-bin/cvename.cgi?name=3DCVE-2009-2957
  [ 2 ] CVE-2009-2958
        http://cve.mitre.org/cgi-bin/cvename.cgi?name=3DCVE-2009-2958

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

  http://security.gentoo.org/glsa/glsa-200909-19.xml

Concerns?
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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
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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