Gentoo: Lynx Buffer overflow in NNTP processing
Posted by Benjamin D. Thomas   
Gentoo Lynx contains a buffer overflow that may be exploited to execute arbitrary code.
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Gentoo Linux Security Advisory                           GLSA 200510-15
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                                            http://security.gentoo.org/
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  Severity: Normal
     Title: Lynx: Buffer overflow in NNTP processing
      Date: October 17, 2005
      Bugs: #108451
        ID: 200510-15

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Synopsis
========

Lynx contains a buffer overflow that may be exploited to execute
arbitrary code.

Background
==========

Lynx is a text-mode browser for the World Wide Web. It supports
multiple URL types, including HTTP and NNTP URLs.

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

    -------------------------------------------------------------------
     Package          /  Vulnerable  /                      Unaffected
    -------------------------------------------------------------------
  1  www-client/lynx     < 2.8.5-r1                        >= 2.8.5-r1

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

When accessing a NNTP URL, Lynx connects to a NNTP server and retrieves
information about the available articles in the target newsgroup. Ulf
Harnhammar discovered a buffer overflow in a function that handles the
escaping of special characters.

Impact
======

An attacker could setup a malicious NNTP server and entice a user to
access it using Lynx (either by creating NNTP links on a web page or by
forcing a redirect for Lynx users). The data returned by the NNTP
server would trigger the buffer overflow and execute arbitrary code
with the rights of the user running Lynx.

Workaround
==========

There is no known workaround at this time.

Resolution
==========

All Lynx users should upgrade to the latest version:

    # emerge --sync
    # emerge --ask --oneshot --verbose ">=www-client/lynx-2.8.5-r1"

References
==========

  [ 1 ] CAN-2005-3120
        http://cve.mitre.org/cgi-bin/cvename.cgi?name=CAN-2005-3120

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

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

  http://security.gentoo.org/glsa/glsa-200510-15.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 2005 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/2.0