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iDefense Security Advisory 03.15.07: Horde Project Cleanup Script Arbitrary File Deletion Vulnerability



Horde Project Cleanup Script Arbitrary File Deletion Vulnerability

iDefense Security Advisory 03.15.07
http://labs.idefense.com/intelligence/vulnerabilities/
Mar 15, 2007

I. BACKGROUND

The Horde Project provides a PHP-based framework, as well as applications
for web-based group collaboration. IMP is their web-mail application. More
information is available from the Horde Project web site at the following
URL.

http://www.horde.org/

II. DESCRIPTION

Local exploitation of an input processing vulnerability within Horde
Project's Horde and IMP allows attackers to delete arbitrary files.

This vulnerability specifically exists due to the improper handling of the
output from an execution of find(1). The output from find(1) is passed
directly to a "for X in Y; do" as the Y value. Since the Y value is
delimited by spaces, the for loop will process files containing spaces in
their path as separate files. An attacker can create a file path
containing spaces to manipulate the output from find(1).

For example, creating the file "/tmp/x /etc/passwd /tmp/mswordx", the
following files will be deleted by the cron script; "/tmp/x",
"/etc/passwd", and "/tmp/mswordx".

III. ANALYSIS

Exploitation allows attackers to delete arbitrary files with the privileges
of the user configured to run the cron script. Since a specially created
path must be created on the local file system, local access is required.

In some cases this script may be installed to run as root. If installed
with lesser privileges, such as that of the web server, this vulnerability
is not quite as severe.

By deleting arbitrary files an attacker could possibly remove access
controls, deny access to the system, or reset configurations. In some
cases, it may be possible for an attacker to gain elevated privileges from
this vulnerability.

IV. DETECTION

iDefense has confirmed the existence of this vulnerability in the cleanup
cron scripts included in the following software packages:

Horde Framework; versions 3.0, 3.0.4, 3.1.3

Horde IMP; versions 2.0.8, 2.0.9, 2.2.8, 2.3.6, 3.0, 3.1, 3.2.1, 3.2.6,
3.2.8

The cleanup script was originally contained within the IMP package. The
script was moved into the Horde Framework with the release of Horde
Framework (H3) 3.0.

V. WORKAROUND

Disabling the vulnerable cron script will effectively prevent exploitation
of this vulnerability.

VI. VENDOR RESPONSE

The Horde Project has corrected the vulnerable cron script within version
3.1.4 of the Horde Application Framework.

VII. CVE INFORMATION

A Mitre Corp. Common Vulnerabilities and Exposures (CVE) number has not
been assigned yet.

VIII. DISCLOSURE TIMELINE

03/07/2007  Initial vendor notification
03/07/2007  Initial vendor response
03/15/2007  Coordinated public disclosure

IX. CREDIT

The discoverer of this vulnerability wishes to remain anonymous.

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X. LEGAL NOTICES

Copyright © 2007 iDefense, Inc.

Permission is granted for the redistribution of this alert electronically.
It may not be edited in any way without the express written consent of
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any other medium other than electronically, please e-mail
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Disclaimer: The information in the advisory is believed to be accurate at
the time of publishing based on currently available information. Use of
the information constitutes acceptance for use in an AS IS condition.
There are no warranties with regard to this information. Neither the
author nor the publisher accepts any liability for any direct, indirect,
or consequential loss or damage arising from use of, or reliance on, this
information.