From: david at majorsecurity dot info
Operating system: Unix
PHP version: 5.3.0
PHP Bug Type: *Directory/Filesystem functions
Bug description: prefix bypass in file_get_contents
Description:
------------
If you use a prefix (i.e myownprefix_ ) in your source code to make sure
that only files containing this prefix can be opened, this can be bypassed
within file_get_contents().
Let's say that you have placed 2 files in your htdocs folder:
1. /htdocs/david/myownprefix_home.php
2. /htdocs/david/home.php
3. /htdocs/bug.php
Reproduce code:
---------------
---
>From manual page: function.file-get-contents
---
Example code (bug.php):
<?php
if(isset($_GET['seite'])) {
$seite = $_GET['seite'];
$datei =
nl2br(file_get_contents("./david/myownprefix_$seite.php"));
echo $datei;
}
?>
Proof of concept:
http://localhost/bug.php?seite=/../home
Expected result:
----------------
Now this would open the file /htdocs/home.php and our defined prefix will
be bypassed.
--
Edit bug report at http://bugs.php.net/?id=49670&edit=1
--
Try a snapshot (PHP 5.2):
http://bugs.php.net/fix.php?id=49670&r=trysnapshot52
Try a snapshot (PHP 5.3):
http://bugs.php.net/fix.php?id=49670&r=trysnapshot53
Try a snapshot (PHP 6.0):
http://bugs.php.net/fix.php?id=49670&r=trysnapshot60
Fixed in SVN:
http://bugs.php.net/fix.php?id=49670&r=fixed
Fixed in SVN and need be documented:
http://bugs.php.net/fix.php?id=49670&r=needdocs
Fixed in release:
http://bugs.php.net/fix.php?id=49670&r=alreadyfixed
Need backtrace:
http://bugs.php.net/fix.php?id=49670&r=needtrace
Need Reproduce Script:
http://bugs.php.net/fix.php?id=49670&r=needscript
Try newer version:
http://bugs.php.net/fix.php?id=49670&r=oldversion
Not developer issue:
http://bugs.php.net/fix.php?id=49670&r=support
Expected behavior:
http://bugs.php.net/fix.php?id=49670&r=notwrong
Not enough info:
http://bugs.php.net/fix.php?id=49670&r=notenoughinfo
Submitted twice:
http://bugs.php.net/fix.php?id=49670&r=submittedtwice
register_globals:
http://bugs.php.net/fix.php?id=49670&r=globals
PHP 4 support discontinued: http://bugs.php.net/fix.php?id=49670&r=php4
Daylight Savings: http://bugs.php.net/fix.php?id=49670&r=dst
IIS Stability:
http://bugs.php.net/fix.php?id=49670&r=isapi
Install GNU Sed:
http://bugs.php.net/fix.php?id=49670&r=gnused
Floating point limitations:
http://bugs.php.net/fix.php?id=49670&r=float
No Zend Extensions:
http://bugs.php.net/fix.php?id=49670&r=nozend
MySQL Configuration Error:
http://bugs.php.net/fix.php?id=49670&r=mysqlcfg
