Advisory: Awstats official workaround flaw

[Maximillian Dornseif <dornseif () informatik rwth-aachen de>]

               Advisory: Awstats official workaround flaw

A group of students at our lab called RedTeam found a flaw in the  
official workaround for the remote command
execution vulnerability in awstats discovered by iDefense.


Details
=======

Product: Awstats
Affected Version: <= 6.2
Immune Version: 6.3
OS affected: all
Security-Risk: high
Remote-Exploit: yes
Vendor-URL: http://awstats.sourceforge.net
Vendor-Status: informed
Advisory-URL:
http://tsyklon.informatik.rwth-aachen.de/redteam/advisories/rt-sa-2005 
-006
Advisory-Status: public
CVE: GENERIC-MAP-NOMATCH

Introduction
============

iDefense found a remote command execution vulnerability in awstats <=
6.2, see CAN-2005-0116.

The official awstats website tells users that they are safe from remote
command execution if they set the variable
$!AllowToUpdateStatsFromBrowser to 0. This is not true, as the exploit
can still be triggered.

More Details
============

In awstats.pl the variable $configdir, which is used to exploit, can
still be set remotely. Setting $!AllowToUpdateStatsFromBrowser to 0
only removes the link to the button which can be used to trigger
updates. The variable can still be assigned per GET request.

Proof of Concept
================

http://path/to/awstats/awstats.pl?configdir=|cd%20/ 
tmp;%20touch%20evilfile;

Workaround
==========

Use the workaround provided by iDefense. See their advisory for the
original vulnerability.

Fix
===

Fixed in version 6.3.

Security Risk
=============

High, as arbitrary commands can be executed on the vulnerable system.

History
=======

2005-02-12 eldy () users sourceforge net informed
2005-02-12 CVE number requested
2005-02-14 issue does not qualify for a CVE number. posted.

RedTeam
=======

RedTeam is a penetration testing group working at the Laboratory for
Dependable Distributed Systems at RWTH-Aachen University. You can find
more Information on the RedTeam Project at
http://tsyklon.informatik.rwth-aachen.de/redteam/


--
Maximillian Dornseif, Dipl. Jur., CISSP
Laboratory for Dependable Distributed Systems, RWTH Aachen University
Tel. +49 241 80-21431 - http://md.hudora.de/

Attachment: smime.p7s
Description:

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