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$ GET variables

4:44 pm on Dec 8, 2010 (gmt 0)

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Ok, I have been coding for a while mainly in PHP and SQL, but something is confusing ...

I am passing 3 variables via form=get, and action=search.php.

Well, I accidentally left out my variable assignments:


And continued with my query within the search.php. It all still worked. I double checked the file on the server, I searched my document for any $_GET terms and they are not there, so now I am confused.

Is this possible or is it likely that I am missing something?
9:05 pm on Dec 8, 2010 (gmt 0)

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Sounds like you have register globals on in php. This would convert all gets to the corresponding var name.

It's a big security risk. You should turn register globals off and code the vars from $_GET.

Note that it is also unwise to directly use data from $_GET without sanitising it. The following would be more secure:

$fordom='abc'; // default fordom or blank
$category='xyz'; // default category or blank

if(isset($_GET['search'])) $search = substr(filter_var($_GET['search'], FILTER_SANITIZE_STRING), 0, 25);
if(isset($_GET['fordom'])) $fordom = substr(filter_var($_GET['fordom'], FILTER_SANITIZE_STRING), 0, 5);
if(isset($_GET['category'])) $category = substr(filter_var($_GET['category'], FILTER_SANITIZE_STRING), 0, 5);

This will limit the size of data which can be entered and sanitize the string to prevent some exploits.

5:39 pm on Dec 9, 2010 (gmt 0)

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A caveat, FILTER_SANITIZE_STRING is only available for version 5+ and after 4.2.0 [php.net] register_globals default setting is off. But even if you have an old version of PHP, important to cleanse that input.