Nmap rsync-brute NSE Script


This page contains detailed information about how to use the rsync-brute NSE script. For list of all NSE scripts, visit the Nmap NSE Library.

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Overview
Error Messages

Script Overview

Script source code: https://github.com/nmap/nmap/tree/master/scripts/rsync-brute.nse
Script categories: brute, intrusive
Target service / protocol: rsync, tcp
Target network port(s): 873
List of CVEs: -

Script Description

The rsync-brute.nse script performs brute force password auditing against the rsync remote file syncing protocol.

Rsync-brute NSE Script Arguments

This is a full list of arguments supported by the rsync-brute.nse script:

rsync-brute.module

The module against which brute forcing should be performed

creds.global

Credentials to be returned by Credentials.getCredentials regardless of the service.

creds.[service]

Credentials to be returned by Credentials.getCredentials for [service]. E.g. creds.http=admin:password

passdb

The filename of an alternate password database. Default: nselib/data/passwords.lst

unpwdb.passlimit

The maximum number of passwords passwords will return (default unlimited).

unpwdb.timelimit

The maximum amount of time that any iterator will run before stopping. The value is in seconds by default and you can follow it with ms, s, m, or h for milliseconds, seconds, minutes, or hours. For example, unpwdb.timelimit=30m or unpwdb.timelimit=.5h for 30 minutes. The default depends on the timing template level (see the module description). Use the value 0 to disable the time limit.

unpwdb.userlimit

The maximum number of usernames usernames will return (default unlimited).

userdb

The filename of an alternate username database. Default: nselib/data/usernames.lst

brute.credfile

A file containing username and password pairs delimited by '/'

brute.delay

The number of seconds to wait between guesses (default: 0)

brute.emptypass

Guess an empty password for each user (default: false)

brute.firstonly

Stop guessing after first password is found (default: false)

brute.guesses

The number of guesses to perform against each account. (default: 0 (unlimited)). The argument can be used to prevent account lockouts.

brute.mode

Can be user, pass or creds and determines what mode to run the engine in.

  • user - the unpwdb library is used to guess passwords, every password Password is tried for each user. (The user iterator is in the outer loop)
  • pass - the unpwdb library is used to guess passwords, each password Is tried for every user. (The password iterator is in the outer loop)
  • creds - a set of credentials (username and password pairs) are Guessed against the service. This allows for lists of known or common username and password combinations to be tested. If no mode is specified and the script has not added any custom iterator the pass mode will be enabled.

brute.passonly

Iterate over passwords only for services that provide only a password for authentication. (default: false)

brute.retries

The number of times to retry if recoverable failures occur. (default: 2)

brute.start

The number of threads the engine will start with. (default: 5).

brute.threads

The number of initial worker threads, the number of active threads will be automatically adjusted.

brute.unique

Make sure that each password is only guessed once (default: true)

brute.useraspass

Guess the username as password for each user (default: true)

creds.[service]

Credentials to be returned by Credentials.getCredentials for [service]. E.g. creds.http=admin:password

- - -
To use these script arguments, add them to the Nmap command line using the --script-args arg1=value,[arg2=value,..] syntax. For example:

nmap --script=rsync-brute --script-args rsync-brute.module=value,creds.global=value <target>

Rsync-brute NSE Script Example Usage

Here's an example of how to use the rsync-brute.nse script:

nmap -p 873 --script rsync-brute --script-args 'rsync-brute.module=www' <ip>

Rsync-brute NSE Script Example Output

Here's a sample output from the rsync-brute.nse script:

PORT    STATE SERVICE REASON
873/tcp open  rsync   syn-ack
| rsync-brute:
|   Accounts
|     user1:laptop - Valid credentials
|     user2:password - Valid credentials
|   Statistics
|_    Performed 1954 guesses in 20 seconds, average tps: 97

Rsync-brute NSE Script Example XML Output

There is no sample XML output for this module. However, by providing the -oX <file> option, Nmap will produce a XML output and save it in the file.xml file.

Author

  • Patrik Karlsson

References

See Also

Related NSE scripts to the rsync-brute.nse script:

Visit Nmap NSE Library for more scripts.

The rsync-brute.nse script may fail with the following error messages. Check for the possible causes by using the code snippets highlighted below found in the script source code. This can often times help in identifying the root cause of the problem.

Login failed

Here is a relevant code snippet related to the "Login failed" error message:

54:	    if( not(status) and data ~= "Authentication failed" ) then
55:	      local err = brute.Error:new( data )
56:	      err:setRetry( true )
57:	      return false, err
58:	    elseif ( not(status) ) then
59:	      return false, brute.Error:new( "Login failed" )
60:	    else
61:	      return true, creds.Account:new(username, password, creds.State.VALID)
62:	    end
63:	  end,
64:

Failed to create helper

Here is a relevant code snippet related to the "Failed to create helper" error message:

69:	}
70:	
71:	local function isModuleValid(host, port, module)
72:	  local helper = rsync.Helper:new(host, port, { module = module })
73:	  if ( not(helper) ) then
74:	    return false, "Failed to create helper"
75:	  end
76:	  local status, data = helper:connect()
77:	  if ( not(status) ) then
78:	    return false, "Failed to connect to server"
79:	  end

Failed to connect to server

Here is a relevant code snippet related to the "Failed to connect to server" error message:

73:	  if ( not(helper) ) then
74:	    return false, "Failed to create helper"
75:	  end
76:	  local status, data = helper:connect()
77:	  if ( not(status) ) then
78:	    return false, "Failed to connect to server"
79:	  end
80:	  status, data = helper:login()
81:	  if ( status and data == "No authentication was required" ) then
82:	    return false, data
83:	  elseif ( not(status) and data == "Authentication required" ) then

Brute pre-check failed for unknown reason: (%s)

Here is a relevant code snippet related to the "Brute pre-check failed for unknown reason: (%s)" error message:

83:	  elseif ( not(status) and data == "Authentication required" ) then
84:	    return true
85:	  elseif ( not(status) and data == ("Unknown module '%s'"):format(module) ) then
86:	    return false, data
87:	  end
88:	  return false, ("Brute pre-check failed for unknown reason: (%s)"):format(data)
89:	end
90:	
91:	local function fail (err) return stdnse.format_output(false, err) end
92:	
93:	action = function(host, port)

rsync-brute.module was not supplied

Here is a relevant code snippet related to the "rsync-brute.module was not supplied" error message:

92:	
93:	action = function(host, port)
94:	
95:	  local mod = stdnse.get_script_args(SCRIPT_NAME .. ".module")
96:	  if ( not(mod) ) then
97:	    return fail("rsync-brute.module was not supplied")
98:	  end
99:	
100:	  local status, err = isModuleValid(host, port, mod)
101:	  if ( not(status) ) then
102:	    return fail(err)

Version

This page has been created based on Nmap version 7.92.

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