[ GLSA 200804-16 ] rsync: Execution of arbitrary code

[Robert Buchholz <rbu () gentoo org>]

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Gentoo Linux Security Advisory                           GLSA 200804-16
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                                            http://security.gentoo.org/
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  Severity: High
     Title: rsync: Execution of arbitrary code
      Date: April 17, 2008
      Bugs: #216887
        ID: 200804-16

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Synopsis
========

A buffer overflow in rsync might lead to the remote execution of
arbitrary code when extended attributes are being used.

Background
==========

rsync is a file transfer program to keep remote directories
synchronized.

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

    -------------------------------------------------------------------
     Package         /  Vulnerable  /                       Unaffected
    -------------------------------------------------------------------
  1  net-misc/rsync     < 2.6.9-r6                         >= 2.6.9-r6

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

Sebastian Krahmer of SUSE reported an integer overflow in the
expand_item_list() function in the file util.c which might lead to a
heap-based buffer overflow when extended attribute (xattr) support is
enabled.

Impact
======

A remote attacker could send a file containing specially crafted
extended attributes to an rsync deamon, or entice a user to sync from
an rsync server containing specially crafted files, possibly leading to
the execution of arbitrary code.

Please note that extended attributes are only enabled when USE="acl" is
enabled, which is the default setting.

Workaround
==========

Disable extended attributes in the rsync daemon by setting "refuse
options = xattrs" in the file "/etc/rsyncd.conf" (or append "xattrs" to
an existing "refuse" statement). When synchronizing to a server, do not
provide the "-X" parameter to rsync. You can also disable the "acl" USE
flag for rsync and recompile the package.

Resolution
==========

All rsync users should upgrade to the latest version:

    # emerge --sync
    # emerge --ask --oneshot --verbose ">=net-misc/rsync-2.6.9-r6"

References
==========

  [ 1 ] CVE-2008-1720
        http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2008-1720

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

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

  http://security.gentoo.org/glsa/glsa-200804-16.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 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

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