APBoard - post threads to protected forums and possibility to hijack forum-password

[ProXy <proxy () es-crew de>]

Product: Another PHP Program - APBoard
Versions: tested on 2.02, 2.03
Vulnerability: post threads to protected forums and possibility to hijack 
forum-password
Date: November 12, 2002
Discovered by: ProXy <proxy () es-crew de> 

Introduction:
Normal Users can submit threads to password protected forums 
and possibly hijack the forum-password with some referer logging script
I have already informed  APP about this vulnerability!

Exploit:
1, register an account on vuln board

2, go to any forum and klick on "Neues Thema"

3, open sourcecode of this site and scroll down to the following lines:

<---code--->
<INPUT TYPE="hidden" NAME="sess_id" VALUE="">
<INPUT TYPE="hidden" NAME="postit" VALUE="TRUE">
<INPUT TYPE="hidden" NAME="insertinto" VALUE="1">
<INPUT TYPE="hidden" NAME="BoardID" VALUE="1">
<INPUT CLASS="button" TYPE="submit" NAME="new_topic" VALUE="Thema posten">
<INPUT CLASS="button" TYPE="submit" NAME="preview_topic" VALUE="Vorschau">
<---code--->

4, edit the "insertinto" value of the forum where you want to submit the 
new thread.
eg: <INPUT TYPE="hidden" NAME="insertinto" VALUE="12">

5, save file local

6, open file and write your text, then click "Thema posten" and the new 
thread is posted to the protected forum

Another Bug in this Board is that if a user logs into a protected forum
the forum-password will be shown on the title-bar in plaintext
eg: http://www.your-domain.com/apboard/thread.php3?
id=999&passwort=1&thepasswordhere

you could create a referer-logging script and link this in the posted 
thread of the protected  forum. 
if any user clicks on the link the plaintext password would therefore be 
saved in the logs of the attacker

- ProXy
- http://www.es-crew.de