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

[Thierry Carrez <koon () gentoo org>]

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Gentoo Linux Security Advisory                           GLSA 200411-15
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
                                            http://security.gentoo.org/
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

  Severity: Normal
     Title: OpenSSL, Groff: Insecure tempfile handling
      Date: November 08, 2004
      Bugs: #68404, #68407
        ID: 200411-15

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

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 () 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

Attachment: signature.asc
Description: OpenPGP digital signature