XOOPS 2.5.7.2 Directory Traversal

`[+] Credits: John Page aka hyp3rlinx  
  
[+] Website: hyp3rlinx.altervista.org  
  
[+] Source:  
http://hyp3rlinx.altervista.org/advisories/XOOPS-DIRECTORY-TRAVERSAL.txt  
  
  
  
Vendor:  
=============  
xoops.org  
  
  
  
Product:  
================  
Xoops 2.5.7.2  
  
  
  
Vulnerability Type:  
===========================  
Directory Traversal Bypass  
  
  
  
Vulnerability Details:  
=====================  
  
Xoops 2.5.7.2 has checks to defend against directory traversal attacks.  
However, they can be easily bypassed by simply issuing "..././" instead of  
"../"  
  
  
References:  
http://xoops.org/modules/news/article.php?storyid=6757  
  
  
Exploit Codes:  
==============  
  
  
In Xoops code in 'protector.php' the following check is made for dot dot  
slash "../" in HTTP requests  
  
/////////////////////////////////////////////////////////////////////////////////  
  
if( is_array( $_GET[ $key ] ) ) continue ;  
if ( substr( trim( $val ) , 0 , 3 ) == '../' || strstr( $val , '../../' ) )  
{  
$this->last_error_type = 'DirTraversal' ;  
$this->message .= "Directory Traversal '$val' found.\n" ;  
  
////////////////////////////////////////////////////////////////////////////////  
  
The above Xoops directory traversal check can be defeated by using  
..././..././..././..././  
  
you can test the theory by using example below test case by supplying  
..././ to GET param.  
  
$val=$_GET['c'];  
  
if ( substr( trim( $val ) , 0 , 3 ) == '../' || strstr( $val , '../../' ) )  
{  
echo "traversal!";  
}else{  
echo "ok!" . $val;  
}  
  
  
  
Disclosure Date:  
==================================  
Feb 2, 2016: Vendor Notification  
Vendor confirms and patches Xoops  
March 17, 2016 : Public Disclosure  
  
==================================  
  
[+] Disclaimer  
Permission is hereby granted for the redistribution of this advisory,  
provided that it is not altered except by reformatting it, and that due  
credit is given. Permission is explicitly given for insertion in  
vulnerability databases and similar, provided that due credit is given to  
the author.  
The author is not responsible for any misuse of the information contained  
herein and prohibits any malicious use of all security related information  
or exploits by the author or elsewhere. (c) hyp3rlinx.  
  
hyp3rlinx  
`