#22979 [Bgs]: session index names and same name variables prob even with register_globals off

ID: 22979 User updated by: mailinglist dot phpnet at hydras-world dot com Reported By: mailinglist dot phpnet at hydras-world dot com Status: Bogus Bug Type: Variables related Operating System: *nix PHP Version: 4.3.1 New Comment: My ISP told my it was OFF, so i took them at their word. I just noticed this myself and was heading back here to cancel this bug report. Apologies Previous Comments: ------------------------------------------------------------------------ [2003-03-31 07:32:05] rioter@php.net as you can see register globals is on in your php.ini as its not a bug in php its self marking as bogus ------------------------------------------------------------------------ [2003-03-31 07:22:37] mailinglist dot phpnet at hydras-world dot com I wasn't using session_register to register global variables in my code and all session access was through $_SESSION[] so the "register_globals = off" setting shouldn't affect my code, but it did! I wrote all my code with the knowledge that register_globals defaults to OFF on most web-servers and that having the setting off is also more secure. The problem comes about when having variable names the same as index names in the $_SESSION array and when they're not supposed to be set to the same thing. e.g. $ordernumber = $_SESSION['ordernumber']; $ordernumber++; This would have the effect of doing this too: $_SESSION['ordernumber']++; Not good! The solution however was quite simple, and I just used upper case names as my $_SESSION index names. so $_SESSION['ordernumber'] now becomes $_SESSION['ORDERNUMBER']. I've confirmed this to be a bug on the *nix webserver that my ISP uses, but can't reproduce it with a default install in php 4.2.3 and 4.3.1 on my WinXP IIS5.1 setup. To help you out, I added a php script to a test site that shows the problem, along with the output of a phpinfo() call. Here's the script: ==== SCRIPT START ==== <?php ob_start(); session_start(); ?> <html> <body> <?php echo "Session Now: "; var_dump($_SESSION); echo "<br>"; $_SESSION['ordernumber'] = 5; $ordernumber = $_SESSION['ordernumber']; echo "ordernumber = $ordernumber<br>"; echo "Session Before: "; var_dump($_SESSION); echo "<br>"; $ordernumber++; echo "ordernumber = $ordernumber<br>"; echo "Session After: "; var_dump($_SESSION); echo "<br>"; ?> <p>PhpInfo: <? phpinfo(); ?></p> </body> </html> ==== SCRIPT END ==== When the script is run on the ISP's web server this is the output: Session Now: array(1) { ["ordernumber"]=> &int(6) } ordernumber = 5 Session Before: array(1) { ["ordernumber"]=> &int(5) } ordernumber = 6 Session After: array(1) { ["ordernumber"]=> &int(6) } Notice the int(6) on the line above - BAD! When the script is run on my system this is the output: Session Now: array(1) { ["ordernumber"]=> int(5) } ordernumber = 5 Session Before: array(1) { ["ordernumber"]=> int(5) } ordernumber = 6 Session After: array(1) { ["ordernumber"]=> int(5) } Notice the int(5) on the line above! - CORRECT! here's a link to the script, so you can test it for yourselves: http://www.loudretail.com/sessionproblem.php ------------------------------------------------------------------------ -- Edit this bug report at http://bugs.php.net/?id=22979&edit=1