$_REQUEST
If you deploy php code and cannot control whether register_globals is off, place this snippet in your code to prevent session injections:
<?php
if (isset($_REQUEST['_SESSION'])) die("Get lost Muppet!");
?>
$_SESSION
$HTTP_SESSION_VARS [deprecated]
$_SESSION -- $HTTP_SESSION_VARS [deprecated] — Session variables
Description
An associative array containing session variables available to the current script. See the Session functions documentation for more information on how this is used.
$HTTP_SESSION_VARS contains the same initial information, but is not a superglobal. (Note that $HTTP_SESSION_VARS and $_SESSION are different variables and that PHP handles them as such)
Changelog
| Version | Description |
|---|---|
| 4.1.0 | Introduced $_SESSION that deprecated $HTTP_SESSION_VARS. |
Notes
Note: This is a 'superglobal', or automatic global, variable. This simply means that it is available in all scopes throughout a script. There is no need to do global $variable; to access it within functions or methods.
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User Contributed Notes$_SESSION
Dave
18-Nov-2009 12:05
18-Nov-2009 12:05
charlese at cvs dot com dot au
05-Jul-2009 04:47
05-Jul-2009 04:47
I was having troubles with session variables working in some environments and being seriously flaky in others. I was using $_SESSION as an array. It works properly when I used $_SESSION as pointers to arrays. As an example the following code works in some environments and not others.
<?php
//Trouble if I treate $form_convert and $_SESSION['form_convert'] as unrelated items
$form_convert=array();
if (isset($_SESSION['form_convert'])){
$form_convert=$_SESSION['form_convert'];
}
}
?>
The following works well.
<?php
if (isset($_SESSION['form_convert'])){
$form_convert = $_SESSION['form_convert'];
}else{
$form_convert = array();
$_SESSION['form_convert']=$form_convert;
}
?>
bohwaz
01-Sep-2008 12:43
01-Sep-2008 12:43
Please note that if you have register_globals to On, global variables associated to $_SESSION variables are references, so this may lead to some weird situations.
<?php
session_start();
$_SESSION['test'] = 42;
$test = 43;
echo $_SESSION['test'];
?>
Load the page, OK it displays 42, reload the page... it displays 43.
The solution is to do this after each time you do a session_start() :
<?php
if (ini_get('register_globals'))
{
foreach ($_SESSION as $key=>$value)
{
if (isset($GLOBALS[$key]))
unset($GLOBALS[$key]);
}
}
?>
Steve Clay
17-Aug-2008 04:28
17-Aug-2008 04:28
Unlike a real PHP array, $_SESSION keys at the root level must be valid variable names.
<?php
$_SESSION[1][1] = 'cake'; // fails
$_SESSION['v1'][1] = 'cake'; // works
?>
I imagine this is an internal limitation having to do with the legacy function session_register(), where the registered global var must similarly have a valid name.
jherry at netcourrier dot com
02-Aug-2008 02:16
02-Aug-2008 02:16
You may have trouble if you use '|' in the key:
$_SESSION["foo|bar"] = "fuzzy";
This does not work for me. I think it's because the serialisation of session object is using this char so the server reset your session when it cannot read it.
To make it work I replaced '|' by '_'.