NUUO NVRmini, NVRmini2, Crystal and NVRSolo devices have a hidden PHP script that when called, a backdoor user is created with poweruser privileges that is able to read and write files on the affected device. The backdoor user ‘bbb’ when created with the password ‘111111’ by visiting ‘strong_user.php’ script is able to initiate a secure shell session and further steal and/or destroy sensitive information.