Gentoo: Lynx Arbitrary command execution
Posted by Benjamin D. Thomas   
Gentoo =3D=3D=3D=3D=3D=3D=3D=3D An incomplete fix for an issue related to the Lynx URL handler might allow for the remote execution of arbitrary commands.
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Gentoo Linux Security Advisory                           GLSA 200909-15
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                                            http://security.gentoo.org/
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  Severity: Normal
     Title: Lynx: Arbitrary command execution
      Date: September 12, 2009
      Bugs: #243058
        ID: 200909-15

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Synopsis
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An incomplete fix for an issue related to the Lynx URL handler might
allow for the remote execution of arbitrary commands.

Background
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Lynx is a fully-featured WWW client for users running
cursor-addressable, character-cell display devices such as vt100
terminals and terminal emulators.

Affected packages
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    -------------------------------------------------------------------
     Package          /  Vulnerable  /                      Unaffected
    -------------------------------------------------------------------
  1  www-client/lynx     < 2.8.6-r4                        >=3D 2.8.6-r4

Description
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Clint Ruoho reported that the fix for CVE-2005-2929 (GLSA 200511-09)
only disabled the lynxcgi:// handler when not using the advanced mode.

Impact
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A remote attacker can entice a user to access a malicious HTTP server,
causing Lynx to execute arbitrary commands. NOTE: The advanced mode is
not enabled by default. Successful exploitation requires the
"lynxcgi://" protocol to be registered with lynx on the victim's
system.

Workaround
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There is no known workaround at this time.

Resolution
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All Lynx users should upgrade to the latest version:

    # emerge --sync
    # emerge --ask --oneshot --verbose =3Dwww-client/lynx-2.8.6-r4

References
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  [ 1 ] CVE-2005-2929
        http://cve.mitre.org/cgi-bin/cvename.cgi?name=3DCVE-2005-2929
  [ 2 ] CVE-2008-4690
        http://cve.mitre.org/cgi-bin/cvename.cgi?name=3DCVE-2008-4690
  [ 3 ] GLSA 200511-09
        http://www.gentoo.org/security/en/glsa/glsa-200511-09.xml

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-200909-15.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