FYI - How to trap the Union BASE64 exploit with Hackalert

New Member Joined: May 06, 2004 Posts: 7

to trap this exploit after it had gotten through my hack alert script, i simply changed the code at the start of Mainfile.php from

Code:

$checkurl = preg_replace("#(/\*.*\*/)#", "", $_SERVER["QUERY_STRING"]); //Courte


// Raven http://ravenphpscripts.com


if (stristr($checkurl,'%20union%20')) {


        $loc = $_SERVER['QUERY_STRING'];


        header("Location: hackattempt.php?$loc");


        die();

to

Code:

$checkurl = preg_replace("#(/\*.*\*/)#", "", $_SERVER["QUERY_STRING"]); //Courte


// Raven http://ravenphpscripts.com


if (stristr($checkurl,'%20union%20') or


   strstr($checkurl,'eCcgVU5JT04gU0VMRUNUIDEvKjox')) {


        $loc = $_SERVER['QUERY_STRING'];


        header("Location: hackattempt.php?$loc");


        die();

Hope this helps others.

registered · Posted: Wed May 12, 2004 2:24 am

You can change the: eCcgVU5JT04gU0VMRUNUIDEvKjox when exploiting?

(User-level authentication bypass exploit),
That pesky private message exploit and forum too was still getting in to my site and sending me private messages with MY account, and also the power to change my profile and make and or delete posts etc.

In modules.php
before:

Code:

global $nukeuser, $db, $prefix;

Add:

Code:

    if (stristr($_SERVER["QUERY_STRING"],'&user=') AND $name==Private_Messages) header("Location: hackattempt.php");

Thanks to chatserv for that.

However with that addition to modules.php, they was blocked from exploiting it via private messages but they could still get in via forum module. So I changed to this:

Code:




    if (stristr($_SERVER["QUERY_STRING"],'&user=') AND $name==Private_Messages) header("Location: hackattempt.php");


    if (stristr($_SERVER["QUERY_STRING"],'&user=') AND $name==Forums) header("Location: hackattempt.php");

Now they can kiss the hack alert script instead.

Posted: Wed May 12, 2004 2:34 am

Ah, but the eCcgVU5JT04gU0VMRUNUIDEvKjox is the Base64 encoding of the Union statement, so if they change the value, it will no longer do what it's meant to. This is used as a way to get past checking just for the %20UNION%20.

So far, I'm fine on the Forums exploit, as I'm not using the forums module, but thanks for the private message, I'll drop that into my sites right now.

Posted: Wed May 12, 2004 2:37 am

stevewalsh wrote:

Ah, but the eCcgVU5JT04gU0VMRUNUIDEvKjox is the Base64 encoding of the Union statement, so if they change the value, it will no longer do what it's meant to.

Ahh right, ok. Smile

Posted: Sat May 15, 2004 8:57 am

Yet another change

Code:

$checkurl = preg_replace("#(/\*.*\*/)#", "", $_SERVER["QUERY_STRING"]); //Courtesy of http://www.esnider.net


// Raven http://ravenphpscripts.com


if (stristr($checkurl,'%20union%20') or


   strstr($checkurl,'eCcgVU5JT04gU0VMRUNUIDEvKjox') or


    strstr($checkurl,'/*')) {


        $loc = $_SERVER['QUERY_STRING'];


        header("Location: hackattempt.php?$loc");


        die();


}

the extra line will pick up the MySQL break command (/* */).

HTH

Posted: Sat May 15, 2004 9:36 am

Nice I know Ravens been considering an expanded version.

Site Admin/Owner Joined: Aug 27, 2002 Posts: 17088

My latest release traps the /*. I cannot and never have been able to get the base64 exploit to work on my site. So, just for clarification, the base64 exploit still get's past my latest release of hack alert? If so, please try it on my site. Be sure to tell me your IP elsewise you will be banned from the Land of Oz and I contact every ISP, regardless Smile

. PM me your IP if you try the exploit. Thanks.

Regular Joined: May 03, 2004 Posts: 62 Location: USA

Raven wrote:

My latest release traps the /*. I cannot and never have been able to get the base64 exploit to work on my site. So, just for clarification, the base64 exploit still get's past my latest release of hack alert? If so, please try it on my site. Be sure to tell me your IP elsewise you will be banned from the Land of Oz and I contact every ISP, regardless Smile

. PM me your IP if you try the exploit. Thanks.

Raven,

If you want ... I get a variety of new attempts everyday .. I can post you the ones that the hackalert doesn't catch. Usually hackalert catches them before the Protector does ... but there's been a couple that weren't caught. I pm'd the most recent one to Six a little while ago.

Posted: Sat May 15, 2004 1:07 pm

I can try the private message and forum exploit if you like raven. This exploit got through on my site multiple times, until I added the lines to modules.php I mentioned above.

Posted: Sat May 15, 2004 8:40 pm

Just to be clear, the only hacks that my script is aimed at are the UNION types. I have posted another script for the admin.php hack. If you have a union attack that gets through, please PM me the exploit. Thanks!