Nmap openvas-otp-brute NSE Script


This page contains detailed information about how to use the openvas-otp-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/openvas-otp-brute.nse
Script categories: intrusive, brute
Target service / protocol: openvas, tcp
Target network port(s): 9390, 9391
List of CVEs: -

Script Description

The openvas-otp-brute.nse script performs brute force password auditing against a OpenVAS vulnerability scanner daemon using the OTP 1.0 protocol.

Openvas-otp-brute NSE Script Arguments

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

openvas-otp-brute.threads

Sets the number of threads. Default: 4

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=openvas-otp-brute --script-args openvas-otp-brute.threads=value,creds.global=value <target>

Openvas-otp-brute NSE Script Example Usage

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

nmap --script=openvas-otp-brute <target>

Openvas-otp-brute NSE Script Example Output

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

PORT     STATE SERVICE    REASON  VERSION
9391/tcp open  ssl/openvas syn-ack
| openvas-otp-brute:
|   Accounts
|     openvas:openvas - Valid credentials
|   Statistics
|_    Performed 4 guesses in 4 seconds, average tps: 1

Openvas-otp-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

  • Vlatko Kosturjak

References

See Also

Visit Nmap NSE Library for more scripts.

The openvas-otp-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.

Unable to send handshake

Here is a relevant code snippet related to the "Unable to send handshake" error message:

51:	
52:	  login = function( self, username, password )
53:	    local status, err = self.socket:send("< OTP/1.0 >\n")
54:	
55:	    if ( not ( status ) ) then
56:	      local err = brute.Error:new( "Unable to send handshake" )
57:	      err:setAbort(true)
58:	      return false, err
59:	    end
60:	
61:	    local response

Bad handshake from server:

Here is a relevant code snippet related to the "Bad handshake from server: " error message:

59:	    end
60:	
61:	    local response
62:	    status, response = self.socket:receive_buf(match.pattern_limit("\r?\n", 2048), false)
63:	    if ( not(status) or response ~= "< OTP/1.0 >" ) then
64:	      local err = brute.Error:new( "Bad handshake from server: "..response )
65:	      err:setAbort(true)
66:	      return false, err
67:	    end
68:	
69:	    status, err = self.socket:send(username.."\n")

Couldn't send user:

Here is a relevant code snippet related to the "Couldn't send user: " error message:

66:	      return false, err
67:	    end
68:	
69:	    status, err = self.socket:send(username.."\n")
70:	    if ( not(status) ) then
71:	      local err = brute.Error:new( "Couldn't send user: "..username )
72:	      err:setAbort( true )
73:	      return false, err
74:	    end
75:	
76:	    status, err = self.socket:send(password.."\n")

Couldn't send password:

Here is a relevant code snippet related to the "Couldn't send password: " error message:

73:	      return false, err
74:	    end
75:	
76:	    status, err = self.socket:send(password.."\n")
77:	    if ( not(status) ) then
78:	      local err = brute.Error:new( "Couldn't send password: "..password )
79:	      err:setAbort( true )
80:	      return false, err
81:	    end
82:	
83:	    -- Create a buffer and receive the first line

Bad login

Here is a relevant code snippet related to the "Bad login" error message:

84:	    local line
85:	    status, line = self.socket:receive_buf(match.pattern_limit("\r?\n", 2048), false)
86:	
87:	    if (line == nil or string.match(line,"Bad login")) then
88:	      stdnse.debug2("Bad login: %s/%s", username, password)
89:	      return false, brute.Error:new( "Bad login" )
90:	    elseif (string.match(line,"SERVER <|>")) then
91:	
92:	      stdnse.debug1("Good login: %s/%s", username, password)
93:	      return true, creds.Account:new(username, password, creds.State.VALID)
94:	    end

WARNING: Unhandled response: %s

Here is a relevant code snippet related to the "WARNING: Unhandled response: %s" error message:

91:	
92:	      stdnse.debug1("Good login: %s/%s", username, password)
93:	      return true, creds.Account:new(username, password, creds.State.VALID)
94:	    end
95:	
96:	    stdnse.debug1("WARNING: Unhandled response: %s", line)
97:	    return false, brute.Error:new( "unhandled response" )
98:	  end,
99:	
100:	  disconnect = function( self )
101:	    self.socket:close()

unhandled response

Here is a relevant code snippet related to the "unhandled response" error message:

92:	      stdnse.debug1("Good login: %s/%s", username, password)
93:	      return true, creds.Account:new(username, password, creds.State.VALID)
94:	    end
95:	
96:	    stdnse.debug1("WARNING: Unhandled response: %s", line)
97:	    return false, brute.Error:new( "unhandled response" )
98:	  end,
99:	
100:	  disconnect = function( self )
101:	    self.socket:close()
102:	  end,

Version

This page has been created based on Nmap version 7.92.

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