Hello,


Huawei HG510 is a device offered by the Serbian telecom operator, to provide ADSL Internet connection.
Administration of settings on this device is allowed only from local LAN network but not only from
private IP address (eg 192.168.1.1) then You can access with public IP address (only from local LAN again).

There is no CSRF protection so we can create malicious web pages and create some CSRF attacks.
Is user is logged on his device we can change passwords or some another settings.

POC:

http://PUBLIC_IP_OF_USER/password.cgi?sysPassword=BASE64_NEW_PASSWORD 


When I testing this I found one strange behavior with /rebootinfo.cgi (reboot device script).
Normaly for all this CSRF user must be logged into device web interface but if we request: 
http://PUBLIC_IP_OF_USER/rebootinfo.cgi, basic authentication is bypassed and device 
is rebooted.

So we have CSRF + Authentication Bypass that lead to DoS of end user.

If someone have any questions about this please contact me.


Best regards,
Ivan Markovic