Flatnuke 3 - Remote Cookie Manipulation / Privilege Escalation

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Http://www.inj3ct-it.org 	     Staff[at]inj3ct-it[dot]org 

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Flatnuke3 Remote Cookie Manipoulation / Privilege Escalation

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#By KiNgOfThEwOrLd

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PoC:

When an user log in, flatnuke set him a cookie value like this: 
myforum=nomeuser. If we try to change it, flatnuke will ask us to log in 
again. The code is: 


$req = $_SERVER["REQUEST_URI"];
if (strstr($req, "myforum="))
die(_NONPUOI);

So, we can bypass this filter, using nullbyte and login as admin. For example, Replace: 

myforum=yourusername 

with: 

myforum%00=adminusername

PHP Execution PoC:

I saw that in download module, if we set to "1" the fneditmode, we can 
make directory. So, we can write a description for the directory, and 
this description will be saved in 
/Download/[Dir_Name]/description.it.php . Yes, we can insert php code in 
the description and it will be execute! Nice, dontcha? :P 

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# milw0rm.com [2007-10-23]