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Security Corporation Security Advisories


=================================================
Security Corporation Security Advisory [SCSA-022]

Multiple vulnerabilities in Xoops
=================================================

PROGRAM: Xoops
HOMEPAGE: http://www.xoops.org
VULNERABLE VERSIONS: 1.3.X,2.0.X -> 2.0.5
RISK: Low/MEDIUM
IMPACT: SQL Injection
Redefining of local variables
Change of the urls of banners

RELEASE DATE: 2003-12-05


=================================================
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
=================================================

XOOPS is "a dynamic OO (Object Oriented) based open source portal
script written in PHP. XOOPS is the ideal tool for developing small
to large dynamic community websites,intra company portals, corporate
portals, weblogs and much more."

(direct quote from XOOPS website)


2. DETAILS
=================================================

- SQL Injection

A vulnerability has been discovered in the banners.php file that
allows unauthorized users to redefine local variables and inject
SQL commands.

Vulnerable code :

<?

[...]

function EmailStats($login, $cid, $bid, $pass)
{
global $xoopsDB, $xoopsConfig;
$result2 = $xoopsDB->query("select name, email from
".$xoopsDB->prefix("bannerclient")." where cid=$cid");
list($name, $email) = $xoopsDB->fetchRow($result2);
if ( $email == "" ) {
redirect_header("banners.php",3,"There isn't an email associated with
client ".$name.".<br />Please contact the Administrator");

exit();
} else {
$result = $xoopsDB->query("select bid, imptotal, impmade, clicks,
imageurl, clickurl, date from ".$xoopsDB->prefix("banner")." where bid=$bid
and cid=$cid");
list($bid, $imptotal, $impmade, $clicks, $imageurl, $clickurl, $date) =
$xoopsDB->fetchRow($result);
[...]

$fecha = date("F jS Y, h:iA.");
$subject = "Your Banner Statistics at ".$xoopsConfig[sitename]."";
$message = "Following are the complete stats for your advertising
investment at ". $xoopsConfig['sitename']." :\n\n\nClient Name:
$name\nBanner ID: $bid\nBanner Image: $imageurl\nBanner URL:
$clickurl\n\nImpressions Purchased: $imptotal\nImpressions Made:
$impmade\nImpressions Left: $left\nClicks Received: $clicks\nClicks Percent:
$percent%\n\n\nReport Generated on: $fecha";
$xoopsMailer =& getMailer();
$xoopsMailer->useMail();
$xoopsMailer->setToEmails($email);
$xoopsMailer->setFromEmail($xoopsConfig['adminmail']);
$xoopsMailer->setFromName($xoopsConfig['sitename']);
$xoopsMailer->setSubject($subject);
$xoopsMailer->setBody($message);
$xoopsMailer->send();
redirect_header("banners.php?op=Ok&amp;login=$login&amp;pass=$pass",3,"Statistics
for your banner has been sent to your email address.");
//include "footer.php";
exit();
}
}

function change_banner_url_by_client($login, $pass, $cid, $bid, $url)
{
global $xoopsDB;
$result = $xoopsDB->query("select passwd from
".$xoopsDB->prefix("bannerclient")." where cid=".$cid."");
list($passwd) = $xoopsDB->fetchRow($result);
if ( $pass == $passwd ) {
$xoopsDB->queryF("update ".$xoopsDB->prefix("banner")." set
clickurl='".$url."' where bid=".$bid."");
}
redirect_header("banners.php?op=Ok&amp;login=$login&amp;pass=$pass",3,"URL
has been changed.");
//include "footer.php";
exit();
}

[...]

switch ( $op ) {
case "Change":
change_banner_url_by_client($login, $pass, $cid, $bid, $url);
break;
case "EmailStats":
EmailStats($login, $cid, $bid, $pass);
break;
[...]
}

?>

We see at first in the function EmailStats() that the SQL request :
select name, email from ".$xoopsDB->prefix("bannerclient")." where cid=$cid
is executed.

We can find the structure of the table "bannerclient" in the file
install/sql/mysql.structure.sql :

----------------------------------------------------
CREATE TABLE bannerclient (
cid smallint(5) unsigned NOT NULL auto_increment,
name varchar(60) NOT NULL default '',
contact varchar(60) NOT NULL default '',
email varchar(60) NOT NULL default '',
login varchar(10) NOT NULL default '',
passwd varchar(10) NOT NULL default '',
extrainfo text NOT NULL,
PRIMARY KEY (cid),
KEY login (login)
) TYPE=MyISAM;
----------------------------------------------------

The problem is that if we inject for example in the $cid variable
this value : 1 AND passwd LIKE 'a%'/*, the SQL request will be :
select name,email from bannerclient where cid=1 AND passwd LIKE 'a%'/*

In that case, if the password of the user id of which is 1 begins
by "a", we shall see displaying the message:
"Statistics for your banner has been sent to your email address."

Otherwise the message:
"There isn't an email associated with client .<br />Please contact
the Administrator"

We can find in this way all the hashed password, login, etc....

The second function, change_banner_url_by_client() can allow
whoever to change the url of whatever banner.

In the code :

----------------------------------------------------
$result = $xoopsDB->query("select passwd from
".$xoopsDB->prefix("bannerclient")." where cid=".$cid."");
list($passwd) = $xoopsDB->fetchRow($result);
if ( $pass == $passwd ) {
$xoopsDB->queryF("update ".$xoopsDB->prefix("banner")." set
clickurl='".$url."' where bid=".$bid."");
}
redirect_header("banners.php?op=Ok&amp;login=$login&amp;pass=$pass",3,"URL
has been changed.");
exit();
----------------------------------------------------

Indeed let us imagine that $cid is worth 1, an ID nonexistent.
In that case, the variable $passwd, which is the result of
the request looking for the $cid 1, will have a NO value.

Then comes the check of the password :
-----------------------
if ( $pass == $passwd )
-----------------------

If we give no value in $pass, $passwd being too NULL,
the equality will really dismiss, because $pass and $passwd
are invalid everything them two.

- Redefining of local variables:


The others vulnerabilities are in edituser.php and
imagemanager.php files.

The edituser.php file begins as this:

----------------------------------------------------
<?php
[...]
$xoopsOption['pagetype'] = 'user';
include 'mainfile.php';
include_once XOOPS_ROOT_PATH.'/class/xoopsformloader.php';

// If not a user, redirect
if ( !$xoopsUser ) {
redirect_header('index.php',3,_US_NOEDITRIGHT);
exit();
}

// initialize $op variable
$op = 'editprofile';

if (isset($HTTP_POST_VARS)) {
foreach ($HTTP_POST_VARS as $k => $v) {
${$k} = $v;
}
}
[...]
----------------------------------------------------


Vulnerable code :

----------------------------------------------------
if (isset($HTTP_POST_VARS)) {
foreach ($HTTP_POST_VARS as $k => $v) {
${$k} = $v;
}
}
----------------------------------------------------

This code transforms all POST variables into
local variables.

It thus allows to REDEFINE already defined variables,
as variables containing classes, or variables of configuration

The same problem is in imagemanager.php, the beginning of
the code is :

----------------------------------------------------
<?php
[...]
include './mainfile.php';
if (!isset($HTTP_GET_VARS['target']) && !isset($HTTP_POST_VARS['target'])) {
exit();
}
$op = 'list';
if (isset($HTTP_GET_VARS['op']) && $HTTP_GET_VARS['op'] == 'upload') {
$op = 'upload';
}
if (isset($HTTP_POST_VARS)) {
foreach ($HTTP_POST_VARS as $k => $v) {
${$k} = $v;
}
}
[...]
----------------------------------------------------


- Change of the urls of banners :

Finally comes the request:

----------------------------------------------------
update ".$xoopsDB->prefix("banner")." set clickurl='".$url."' where
bid=".$bid
----------------------------------------------------

A vulnerability was discovered allowing to change the url of
redirection of a banner according to the bid, what does not
raise seen problem that we do not still have it defines.


3. EXPLOITS
=================================================

- SQL Injection (if magic_quotes_gpc=OFF):

http://[target]/banners.php?op=EmailStats&cid=1%20AND%20passwd%20LIKE%20'a%'/*


- Change of the urls of banners :

http://[target]/banners.php?op=Change&cid=-1&bid=100&url=HTTP://WWW.NEWURL.COM


4. SOLUTIONS
=================================================

You can found a patch at the following link : http://www.phpsecure.info

The creator (Onokazu) was notified and published a secure version 2.0.5.1


5. WORKAROUND
=================================================

In banners.php, replace the function change_banner_url_by_client() by :

----------------------------------------------------
function change_banner_url_by_client($login, $pass, $cid, $bid, $url)
{
global $xoopsDB;
if ( !empty($cid) AND !empty($bid) AND !empty($pass) ){
$result = $xoopsDB->query("select passwd from
".$xoopsDB->prefix("bannerclient")." where cid='".$cid."'");
list($passwd) = $xoopsDB->fetchRow($result);
if ( $pass == $passwd ) {
$xoopsDB->queryF("update ".$xoopsDB->prefix("banner")." set
clickurl='".$url."' where bid='".$bid."'");
}
redirect_header("banners.php?op=Ok&amp;login=$login&amp;pass=$pass",3,"URL
has been changed.");
//include "footer.php";
}
exit();
}
----------------------------------------------------

Add simply the following line just before "switch($op) {" :

--------------------
$cid = intval($cid);
$bid = intval($bid);
--------------------

In edituser.php and imagemanager.php files, replace the following code :

----------------------------------------------------
if (isset($HTTP_POST_VARS)) {
foreach ($HTTP_POST_VARS as $k => $v) {
${$k} = $v;
}
}
----------------------------------------------------

by :


----------------------------------------------------
$forbidden =
array('forbidden','sess_handler','member_handler','config_handler',
'xoopsUserIsAdmin','xoopsUser','xoopsDB','xoopsLogger',
'xoopsConfig','XoopsOption');
if (isset($HTTP_POST_VARS)) {
foreach ($HTTP_POST_VARS as $k => $v) {
if ( !in_array($k,$forbidden) ){
${$k} = $v;
}
}
}
----------------------------------------------------


6. DISCLOSURE TIMELINE
=================================================

21/11/2003 Vulnerability discovered
21/11/2003 Vendor notified
21/11/2003 Vendor response
21/11/2003 Security Corporation clients notified
21/11/2003 Started e-mail discussions
05/12/2003 Last e-mail received
05/12/2003 Public disclosure


7. CREDITS
=================================================

frog-m@n <frog-man@security-corporation.com> is credited with this discovery

Magistrat <http://www.blocus-zone.com> is greeted.


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-022.html

- Version Fran├žaise:
http://www.security-corporation.com/index.php?id=advisories&a=022-FR


10. FEEDBACK
=================================================

Please send suggestions, updates, and comments to:

Security Corporation
http://www.security-corporation.com/
advisory@security-corporation.com



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