[J65nko]

On the FreeBSD webserver I used pf to block port 3306 for external access. But people can do still access phpMyAdmin from their homes. Remember that phpMyAdmin is running on the webserver locally and thus can access 127.0.0.1:3306 or it can use the Unix domain socket:

$  netstat -an -f unix | grep mysql 
0xfffffe802fa5f988 stream      0      0 0xfffffe8020b08080                0x0
  0x0                0x0 /var/run/mysql/mysql.sock