VNC Authentication Scanner - Metasploit
This page contains detailed information about how to use the auxiliary/scanner/vnc/vnc_login metasploit module. For list of all metasploit modules, visit the Metasploit Module Library.
Module Overview
Name: VNC Authentication Scanner
Module: auxiliary/scanner/vnc/vnc_login
Source code: modules/auxiliary/scanner/vnc/vnc_login.rb
Disclosure date: -
Last modification time: 2021-08-31 17:10:07 +0000
Supported architecture(s): -
Supported platform(s): -
Target service / protocol: -
Target network port(s): 5900, 5901, 5902, 5903, 5904, 5905, 5906, 5907, 5908, 5909, 5910
List of CVEs: CVE-1999-0506
This module will test a VNC server on a range of machines and report successful logins. Currently it supports RFB protocol version 3.3, 3.7, 3.8 and 4.001 using the VNC challenge response authentication method.
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
This module is a scanner module, and is capable of testing against multiple hosts.
msf > use auxiliary/scanner/vnc/vnc_login
msf auxiliary(vnc_login) > show options
... show and set options ...
msf auxiliary(vnc_login) > set RHOSTS ip-range
msf auxiliary(vnc_login) > exploit
Other examples of setting the RHOSTS option:
Example 1:
msf auxiliary(vnc_login) > set RHOSTS 192.168.1.3-192.168.1.200
Example 2:
msf auxiliary(vnc_login) > set RHOSTS 192.168.1.1/24
Example 3:
msf auxiliary(vnc_login) > set RHOSTS file:/tmp/ip_list.txt
Required Options
- RHOSTS: The target host(s), range CIDR identifier, or hosts file with syntax 'file:<path>'
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Msfconsole Usage
Here is how the scanner/vnc/vnc_login auxiliary module looks in the msfconsole:
msf6 > use auxiliary/scanner/vnc/vnc_login
msf6 auxiliary(scanner/vnc/vnc_login) > show info
Name: VNC Authentication Scanner
Module: auxiliary/scanner/vnc/vnc_login
License: Metasploit Framework License (BSD)
Rank: Normal
Provided by:
carstein <[email protected]>
jduck <[email protected]>
Check supported:
No
Basic options:
Name Current Setting Required Description
---- --------------- -------- -----------
BLANK_PASSWORDS false no Try blank passwords for all users
BRUTEFORCE_SPEED 5 yes How fast to bruteforce, from 0 to 5
DB_ALL_CREDS false no Try each user/password couple stored in the current database
DB_ALL_PASS false no Add all passwords in the current database to the list
DB_ALL_USERS false no Add all users in the current database to the list
PASSWORD no The password to test
PASS_FILE /opt/metasploit-framework/embedded/framework/data/wordlists/vnc_passwords.txt no File containing passwords, one per line
Proxies no A proxy chain of format type:host:port[,type:host:port][...]
RHOSTS yes The target host(s), range CIDR identifier, or hosts file with syntax 'file:<path>'
RPORT 5900 yes The target port (TCP)
STOP_ON_SUCCESS false yes Stop guessing when a credential works for a host
THREADS 1 yes The number of concurrent threads (max one per host)
USERNAME <BLANK> no A specific username to authenticate as
USERPASS_FILE no File containing users and passwords separated by space, one pair per line
USER_AS_PASS false no Try the username as the password for all users
USER_FILE no File containing usernames, one per line
VERBOSE true yes Whether to print output for all attempts
Description:
This module will test a VNC server on a range of machines and report
successful logins. Currently it supports RFB protocol version 3.3,
3.7, 3.8 and 4.001 using the VNC challenge response authentication
method.
References:
https://nvd.nist.gov/vuln/detail/CVE-1999-0506
Module Options
This is a complete list of options available in the scanner/vnc/vnc_login auxiliary module:
msf6 auxiliary(scanner/vnc/vnc_login) > show options
Module options (auxiliary/scanner/vnc/vnc_login):
Name Current Setting Required Description
---- --------------- -------- -----------
BLANK_PASSWORDS false no Try blank passwords for all users
BRUTEFORCE_SPEED 5 yes How fast to bruteforce, from 0 to 5
DB_ALL_CREDS false no Try each user/password couple stored in the current database
DB_ALL_PASS false no Add all passwords in the current database to the list
DB_ALL_USERS false no Add all users in the current database to the list
PASSWORD no The password to test
PASS_FILE /opt/metasploit-framework/embedded/framework/data/wordlists/vnc_passwords.txt no File containing passwords, one per line
Proxies no A proxy chain of format type:host:port[,type:host:port][...]
RHOSTS yes The target host(s), range CIDR identifier, or hosts file with syntax 'file:<path>'
RPORT 5900 yes The target port (TCP)
STOP_ON_SUCCESS false yes Stop guessing when a credential works for a host
THREADS 1 yes The number of concurrent threads (max one per host)
USERNAME <BLANK> no A specific username to authenticate as
USERPASS_FILE no File containing users and passwords separated by space, one pair per line
USER_AS_PASS false no Try the username as the password for all users
USER_FILE no File containing usernames, one per line
VERBOSE true yes Whether to print output for all attempts
Advanced Options
Here is a complete list of advanced options supported by the scanner/vnc/vnc_login auxiliary module:
msf6 auxiliary(scanner/vnc/vnc_login) > show advanced
Module advanced options (auxiliary/scanner/vnc/vnc_login):
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
MaxGuessesPerService 0 no Maximum number of credentials to try per service instance. If set to zero or a non-number, this option will not be used.
MaxGuessesPerUser 0 no Maximum guesses for a particular username for the service instance. Note that users are considered unique among different services, so a user at 10.1.1.1:22 is different from one at 10.2.2.2:
22, and both will be tried up to the MaxGuessesPerUser limit. If set to zero or a non-number, this option will not be used.
MaxMinutesPerService 0 no Maximum time in minutes to bruteforce the service instance. If set to zero or a non-number, this option will not be used.
REMOVE_PASS_FILE false yes Automatically delete the PASS_FILE on module completion
REMOVE_USERPASS_FILE false yes Automatically delete the USERPASS_FILE on module completion
REMOVE_USER_FILE false yes Automatically delete the USER_FILE on module completion
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)
ShowProgress true yes Display progress messages during a scan
ShowProgressPercent 10 yes The interval in percent that progress should be shown
TRANSITION_DELAY 0 no Amount of time (in minutes) to delay before transitioning to the next user in the array (or password when PASSWORD_SPRAY=true)
WORKSPACE no Specify the workspace for this module
Auxiliary Actions
This is a list of all auxiliary actions that the scanner/vnc/vnc_login module can do:
msf6 auxiliary(scanner/vnc/vnc_login) > show actions
Auxiliary actions:
Name Description
---- -----------
Evasion Options
Here is the full list of possible evasion options supported by the scanner/vnc/vnc_login auxiliary module in order to evade defenses (e.g. Antivirus, EDR, Firewall, NIDS etc.):
msf6 auxiliary(scanner/vnc/vnc_login) > 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:
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.
<IP>:<RPORT> - LOGIN FAILED: <RESULT.CREDENTIAL> (<RESULT.STATUS>: <RESULT.PROOF>)
Here is a relevant code snippet related to the "<IP>:<RPORT> - LOGIN FAILED: <RESULT.CREDENTIAL> (<RESULT.STATUS>: <RESULT.PROOF>)" error message:
95: create_credential_login(credential_data)
96:
97: print_good "#{ip}:#{rport} - Login Successful: #{result.credential}"
98: else
99: invalidate_login(credential_data)
100: vprint_error "#{ip}:#{rport} - LOGIN FAILED: #{result.credential} (#{result.status}: #{result.proof})"
101: end
102: end
103:
104: end
105: end
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Related Pull Requests
- #14696 Merged Pull Request: Zeitwerk rex folder
- #12022 Merged Pull Request: Deregister PASSWORD_SPRAY option for LoginScanner modules
- #8716 Merged Pull Request: Print_Status -> Print_Good (And OCD bits 'n bobs)
- #8338 Merged Pull Request: Fix msf/core and self.class msftidy warnings
- #6655 Merged Pull Request: use MetasploitModule as a class name
- #6648 Merged Pull Request: Change metasploit class names
- #6014 Merged Pull Request: Related to #4803, Update LoginScanner modules to have into account TCP advanced options
- #5555 Merged Pull Request: Add Support For RFB Version 4 (Newer VNC Servers)
- #5059 Merged Pull Request: Yard doc corrections
- #4737 Merged Pull Request: Preserve Context in LoginScanner socket calls, fixes #4723
- #4364 Merged Pull Request: Modules should respect bruteforce_speed again
- #4057 Merged Pull Request: Re-eneable tcp evasions in some LoginScanners
- #3999 Merged Pull Request: Fix #3995 - Make negative messages less verbose for LoginScanner modules
- #3746 Merged Pull Request: Feature/msp 11162/db all creds
- #2525 Merged Pull Request: Change module boilerplate
- #1228 Merged Pull Request: MSFTIDY cleanup #1 - auxiliary
References
See Also
Check also the following modules related to this module:
- auxiliary/scanner/mssql/mssql_login
- auxiliary/scanner/smb/smb_login
- auxiliary/scanner/vnc/vnc_none_auth
- auxiliary/scanner/vnc/ard_root_pw
- exploit/multi/vnc/vnc_keyboard_exec
- post/osx/gather/vnc_password_osx
- auxiliary/admin/vnc/realvnc_41_bypass
- exploit/windows/vnc/realvnc_client
- exploit/windows/vnc/ultravnc_client
- exploit/windows/vnc/ultravnc_viewer_bof
- exploit/windows/vnc/winvnc_http_get
- auxiliary/scanner/http/thinvnc_traversal
- auxiliary/server/capture/vnc
- exploit/dialup/multi/login/manyargs
Related Nessus plugins:
Authors
- carstein <carstein.sec[at]gmail.com>
- jduck
Version
This page has been produced using Metasploit Framework version 6.1.28-dev. For more modules, visit the Metasploit Module Library.
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