[Andreas]

Yes, you can avoid using global.php.

The important cookies are bbuserid and bbpassword.

If you have these cookies you can verify if the combination is valid and retrieve the username from table user.

For vB3

PHP Code:

$userid = intval($_COOKIE[bbuserid]);
$password = addslashes($_COOKIE[bbpassword]);
$result = mysql_query("SELECT username, userid FROM user WHERE userid=$userid AND MD5(CONCAT(password, 'LicenseNo')) = '$password'");
$user = mysql_fetch_array($result);
if ($user[userid])
  // valid
else
  // invalid 


Please note that LicenseNo must be replaced with you vB license number.
You must also make sure that you have selected the correct database before executing this query, if your other tables are in another database.