note 42951 modified in function.count by danbrown
| From: | danbrown@php.net | Date: | Fri, 09 Jan 2009 23:02:00 +0000 |
| Subject: | note 42951 modified in function.count by danbrown | ||
| References: | 1 | Groups: | php.notes |
| Request: | Send a blank email to php-notes+get-149015@lists.php.net to get a copy of this message | ||
I have found on upload scripts or on file manipulation scripts that people can trick a classic file
type filter:
example:
<?php
$filename="bob.jpg.wav";
$bits= explode(".",$filename);
$extention= $bits[1];
if($extention == "jpg"){ echo"Not correct"; exit; }
?>
This returns the filename extention as jpg not wav.
One way to change this is to use count() :
example:
<?php
$filename="bob.jpg.wav";
$bits= explode(".",$filename);
$extention= $bits[count($bits) - 1];
if($extention == "jpg"){ echo "Not correct"; exit; }
?>
This returns the filename extention as wav not jpg.
--was--
I have found on upload scripts or on file manipulation scripts that people can trick a classic file
type filter:
example:
<?php
$filename="bob.jpg.wav";
$bits= explode(".",$filename);
$extention= $bits[1];
if($extention == "jpg"){ echo"Not correct"; exit; }
?>
This returns the filename extention as jpg not wav.
One way to change this is to use count() :
example:
<?php
$filename="bob.jpg.wav";
$bits= explode(".",$filename);
$extention= $bits[count($bits) - 1];
if($extention == "jpg"){ echo"Not correct"; exit; }
?>
This returns the filename extention as wav not jpg.
http://php.net/manual/en/function.count.php