[ GLSA 200411-15 ] OpenSSL, Groff: Insecure tempfile handling

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Gentoo Linux Security Advisory GLSA 200411-15
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                                            http://security.gentoo.org/
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  Severity: Normal
     Title: OpenSSL, Groff: Insecure tempfile handling
      Date: November 08, 2004
      Bugs: #68404, #68407
        ID: 200411-15

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Synopsis
========

groffer, included in the Groff package, and the der_chop script,
included in the OpenSSL package, are both vulnerable to symlink
attacks, potentially allowing a local user to overwrite arbitrary
files with the rights of the user running the utility.

Background
==========

OpenSSL is a toolkit implementing the Secure Sockets Layer and
Transport Layer Security protocols as well as a general-purpose
cryptography library. It includes the der_chop script, which is used to
convert DER-encoded certificates to PEM format. Groff (GNU Troff) is a
typesetting package which reads plain text mixed with formatting
commands and produces formatted output. It includes groffer, a command
used to display groff files and man pages on X and tty.

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

    -------------------------------------------------------------------
     Package / Vulnerable / Unaffected
    -------------------------------------------------------------------
  1 dev-libs/openssl < 0.9.7d-r2 >= 0.9.7d-r2
  2 sys-apps/groff < 1.19.1-r2 >= 1.19.1-r2
    -------------------------------------------------------------------
     2 affected packages on all of their supported architectures.
    -------------------------------------------------------------------

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

groffer and the der_chop script create temporary files in
world-writeable directories with predictable names.

Impact
======

A local attacker could create symbolic links in the temporary files
directory, pointing to a valid file somewhere on the filesystem. When
groffer or der_chop is executed, this would result in the file being
overwritten with the rights of the user running the utility, which
could be the root user.

Workaround
==========

There is no known workaround at this time.

Resolution
==========

All Groff users should upgrade to the latest version:

    # emerge --sync
    # emerge --ask --oneshot --verbose ">=sys-apps/groff-1.19.1-r2"

All OpenSSL users should upgrade to the latest version:

    # emerge --sync
    # emerge --ask --oneshot --verbose ">=dev-libs/openssl-0.9.7d-r2"

Note: /etc/ssl/misc/der_chop is protected by Portage as a configuration
file. Don't forget to use etc-update and overwrite the old version with
the new one.

References
==========

  [ 1 ] CAN-2004-0969
        http://cve.mitre.org/cgi-bin/cvename.cgi?name=CAN-2004-0969
  [ 2 ] CAN-2004-0975
        http://cve.mitre.org/cgi-bin/cvename.cgi?name=CAN-2004-0975

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

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

  http://security.gentoo.org/glsa/glsa-200411-15.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_at_gentoo.org or alternatively, you may file a bug at
http://bugs.gentoo.org.

License
=======

Copyright 2004 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/1.0

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