[ GLSA 200804-03 ] OpenSSH: Privilege escalation

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Gentoo Linux Security Advisory GLSA 200804-03
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                                            http://security.gentoo.org/
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  Severity: Normal
     Title: OpenSSH: Privilege escalation
      Date: April 05, 2008
      Bugs: #214985, #215702
        ID: 200804-03

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Synopsis
========

Two flaws have been discovered in OpenSSH which could allow local
attackers to escalate their privileges.

Background
==========

OpenSSH is a complete SSH protocol implementation that includes an SFTP
client and server support.

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

    -------------------------------------------------------------------
     Package / Vulnerable / Unaffected
    -------------------------------------------------------------------
  1 net-misc/openssh < 4.7_p1-r6 >= 4.7_p1-r6

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

Two issues have been discovered in OpenSSH:

* Timo Juhani Lindfors discovered that OpenSSH sets the DISPLAY
  variable in SSH sessions using X11 forwarding even when it cannot
  bind the X11 server to a local port in all address families
  (CVE-2008-1483).

* OpenSSH will execute the contents of the ".ssh/rc" file even when
  the "ForceCommand" directive is enabled in the global sshd_config
  (CVE-2008-1657).

Impact
======

A local attacker could exploit the first vulnerability to hijack
forwarded X11 sessions of other users and possibly execute code with
their privileges, disclose sensitive data or cause a Denial of Service,
by binding a local X11 server to a port using only one address family.
The second vulnerability might allow local attackers to bypass intended
security restrictions and execute commands other than those specified
by "ForceCommand" if they are able to write to their home directory.

Workaround
==========

There is no known workaround at this time.

Resolution
==========

All OpenSSH users should upgrade to the latest version:

    # emerge --sync
    # emerge --ask --oneshot --verbose ">=net-misc/openssh-4.7_p1-r6"

References
==========

  [ 1 ] CVE-2008-1483
        http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2008-1483
  [ 2 ] CVE-2008-1657
        http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2008-1657

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

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

  http://security.gentoo.org/glsa/glsa-200804-03.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_at_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