Gentoo: GnuTLS Execution of arbitrary code
Posted by Benjamin D. Thomas   
Gentoo Multiple vulnerabilities might allow for the execution of arbitrary code in daemons using GnuTLS.
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Gentoo Linux Security Advisory                           GLSA 200805-20
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                                            http://security.gentoo.org/
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  Severity: High
     Title: GnuTLS: Execution of arbitrary code
      Date: May 21, 2008
      Bugs: #222823
        ID: 200805-20

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Synopsis
========

Multiple vulnerabilities might allow for the execution of arbitrary
code in daemons using GnuTLS.

Background
==========

GnuTLS is an implementation of Secure Sockets Layer (SSL) 3.0 and
Transport Layer Security (TLS) 1.0, 1.1 and 1.2.

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

    -------------------------------------------------------------------
     Package          /  Vulnerable  /                      Unaffected
    -------------------------------------------------------------------
  1  net-libs/gnutls       < 2.2.5                            >= 2.2.5

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

Ossi Herrala and Jukka Taimisto of Codenomicon reported three
vulnerabilities in libgnutls of GnuTLS:

* "Client Hello" messages containing an invalid server name can lead
  to a buffer overflow when evaluating "Security Parameters"
  (CVE-2008-1948).

* Multiple "Client Hello" messages can lead to a NULL pointer
  dereference (CVE-2008-1949).

* A TLS handshake including an encrypted "Client Hello" message and
  an invalid record length could lead to a buffer overread
  (CVE-2008-1950).

Impact
======

Unauthenticated remote attackers could exploit these vulnerabilities to
cause Denial of Service conditions in daemons using GnuTLS. The first
vulnerability (CVE-2008-1948) might allow for the execution of
arbitrary code with the privileges of the daemon handling incoming TLS
connections.

Workaround
==========

There is no known workaround at this time.

Resolution
==========

All GnuTLS users should upgrade to the latest version:

    # emerge --sync
    # emerge --ask --oneshot --verbose ">=net-libs/gnutls-2.2.5"

References
==========

  [ 1 ] CVE-2008-1948
        http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2008-1948
  [ 2 ] CVE-2008-1949
        http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2008-1949
  [ 3 ] CVE-2008-1950
        http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2008-1950

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

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

  http://security.gentoo.org/glsa/glsa-200805-20.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@gentoo.org or alternatively, you may file a bug at
http://bugs.gentoo.org.

License
=======

Copyright 2008 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