Nmap dicom-brute NSE Script

Script Overview

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Script source code: https://github.com/nmap/nmap/tree/master/scripts/dicom-brute.nse
Script categories: auth, brute
Target service / protocol: dicom, tcp
Target network port(s): 104, 2345, 2761, 2762, 4242, 11112
List of CVEs: -

Script Description

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The dicom-brute.nse script attempts to brute force the Application Entity Title of a DICOM server (DICOM Service Provider).

Application Entity Titles (AET) are used to restrict responses only to clients knowing the title. Hence, the called AET is used as a form of password.

Dicom-brute NSE Script Arguments

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

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

dicom.called_aet

Called Application Entity Title. Default: ANY-SCP

dicom.calling_aet

Calling Application Entity Title. Default: ECHOSCU

- - -
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=dicom-brute --script-args creds.global=value,creds.\[service]=value <target>

Dicom-brute NSE Script Example Usage

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

nmap -p4242 --script dicom-brute <target>

nmap -sV --script dicom-brute <target>

nmap --script dicom-brute --script-args passdb=aets.txt <target>

Dicom-brute NSE Script Example Output

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

PORT     STATE SERVICE        REASON
4242/tcp open  vrml-multi-use syn-ack
| dicom-brute:
|   Accounts:
|     Called Application Entity Title:ORTHANC - Valid credentials
|_  Statistics: Performed 5 guesses in 1 seconds, average tps: 5.0

Dicom-brute NSE Script Example XML Output

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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

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• Paulino Calderon <calderon()calderonpale.com>

References

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• https://nmap.org/nsedoc/scripts/dicom-brute.html
• https://github.com/nmap/nmap/tree/master/scripts/dicom-brute.nse

See Also

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

• dicom-ping.nse

Visit Nmap NSE Library for more scripts.

The dicom-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.

Incorrect AET

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Here is a relevant code snippet related to the "Incorrect AET" error message:

54:	    stdnse.debug2("Trying with called AE title:%s", password)
55:	    local dcm_conn, err = dicom.associate(self.host, self.port, nil, password)
56:	    if dcm_conn then
57:	      return true, creds.Account:new("Called Application Entity Title", password, creds.State.VALID)
58:	    else
59:	      return false, brute.Error:new("Incorrect AET")
60:	    end
61:	
62:	  end,
63:	  check = function(self)
64:	    local dcm_conn, err = dicom.associate(self.host, self.port)

DICOM SCU allows any AET

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Here is a relevant code snippet related to the "DICOM SCU allows any AET" error message:

61:	
62:	  end,
63:	  check = function(self)
64:	    local dcm_conn, err = dicom.associate(self.host, self.port)
65:	    if dcm_conn then
66:	      return false, "DICOM SCU allows any AET"
67:	    end
68:	    return true
69:	  end
70:	}
71: