Nmap smb2-capabilities NSE Script

Script Overview

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Script source code: https://github.com/nmap/nmap/tree/master/scripts/smb2-capabilities.nse
Script categories: safe, discovery
Target service / protocol: smb, netbios, tcp, udp
Target network port(s): 137, 139, 445
List of CVEs: -

Script Description

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The smb2-capabilities.nse script attempts to list the supported capabilities in a SMBv2 server for each enabled dialect.

The script sends a SMB2_COM_NEGOTIATE command and parses the response using the SMB dialects:

• 2.0.2
• 2.1
• 3.0
• 3.0.2
• 3.1.1

References:

• https://msdn.microsoft.com/en-us/library/cc246561.aspx

Smb2-capabilities NSE Script Arguments

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This is a full list of arguments supported by the smb2-capabilities.nse script:

smbdomain

The domain to log in with. If you aren't in a domain environment, then anything will (should?) be accepted by the server.

smbhash

A password hash to use when logging in. This is given as a single hex string (32 characters) or a pair of hex strings (both 32 characters, optionally separated by a single character). These hashes are the LanMan or NTLM hash of the user's password, and are stored on disk or in memory. They can be retrieved from memory using the fgdump or pwdump tools.

smbnoguest

Use to disable usage of the 'guest' account.

smbpassword

The password to connect with. Be cautious with this, since some servers will lock accounts if the incorrect password is given. Although it's rare that the Administrator account can be locked out, in the off chance that it can, you could get yourself in trouble. To use a blank password, leave this parameter off altogether.

smbtype

The type of SMB authentication to use. These are the possible options:

• v1: Sends LMv1 and NTLMv1.
• LMv1: Sends LMv1 only.
• NTLMv1: Sends NTLMv1 only (default).
• v2: Sends LMv2 and NTLMv2.
• LMv2: Sends LMv2 only.
• NTLMv2: Doesn't exist; the protocol doesn't support NTLMv2 alone. The default, NTLMv1, is a pretty decent compromise between security and compatibility. If you are paranoid, you might want to use v2 or lmv2 for this. (Actually, if you're paranoid, you should be avoiding this protocol altogether!). If you're using an extremely old system, you might need to set this to v1 or lm, which are less secure but more compatible. For information, see smbauth.lua.

smbusername

The SMB username to log in with. The forms "DOMAIN\username" and "username@DOMAIN" are not understood. To set a domain, use the smbdomain argument.

randomseed

Set to a value to change the filenames/service names that are randomly generated.

smbbasic

Forces the authentication to use basic security, as opposed to "extended security". Against most modern systems, extended security should work, but there may be cases where you want to force basic. There's a chance that you'll get better results for enumerating users if you turn on basic authentication.

smbport

Override the default port choice. If smbport is open, it's used. It's assumed to be the same protocol as port 445, not port 139. Since it probably isn't possible to change Windows' ports normally, this is mostly useful if you're bouncing through a relay or something.

smbsign

Controls whether or not server signatures are checked in SMB packets. By default, on Windows, server signatures aren't enabled or required. By default, this library will always sign packets if it knows how, and will check signatures if the server says to. Possible values are:

• force: Always check server signatures, even if server says it doesn't support them (will Probably fail, but is technically more secure).
• negotiate: [default] Use signatures if server supports them.
• ignore: Never check server signatures. Not recommended.
• disable: Don't send signatures, at all, and don't check the server's. not recommended. More information on signatures can be found in smbauth.lua.

- - -
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=smb2-capabilities --script-args smbdomain=value,smbhash=value <target>

Smb2-capabilities NSE Script Example Usage

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Here's an example of how to use the smb2-capabilities.nse script:

nmap -p 445 --script smb2-capabilities <target>

nmap -p 139 --script smb2-capabilities <target>

Smb2-capabilities NSE Script Example Output

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Here's a sample output from the smb2-capabilities.nse script:

| smb2-capabilities:
|   2.0.2:
|     Distributed File System
|   2.1:
|     Distributed File System
|     Leasing
|     Multi-credit operations

Smb2-capabilities NSE Script Example XML Output

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Here's a sample XML output from the smb2-capabilities.nse script produced by providing the -oX <file> Nmap option:

 <table key="2.0.2">
 <elem>Distributed File System</elem>
 </table>
 <table key="2.1">
 <elem>Distributed File System</elem>
 <elem>Leasing</elem>
 <elem>Multi-credit operations</elem>
 </table>

Author

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• Paulino Calderon

References

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• https://nmap.org/nsedoc/scripts/smb2-capabilities.html
• https://github.com/nmap/nmap/tree/master/scripts/smb2-capabilities.nse
• https://msdn.microsoft.com/en-us/library/cc246561.aspx

See Also

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Related NSE scripts to the smb2-capabilities.nse script:

• smb2-security-mode.nse
• smb2-time.nse
• smb2-vuln-uptime.nse

Visit Nmap NSE Library for more scripts.

The smb2-capabilities.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.

SMB 2+ not supported

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Here is a relevant code snippet related to the "SMB 2+ not supported" error message:

64:	  end
65:	  local max_dialect
66:	  status, max_dialect = smb2.negotiate_v2(smbstate)
67:	  smb.stop(smbstate)
68:	  if not status then -- None of SMB2 dialects accepted by the target
69:	    return false, "SMB 2+ not supported"
70:	  end
71:	  stdnse.debug2("SMB2: Dialect '%s' is the highest supported", smb2.dialect_name(max_dialect))
72:	
73:	  for i, dialect in pairs(smb2.dialects()) do
74:	    -- we need a clean connection for each negotiate request

Could not establish a connection.

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Here is a relevant code snippet related to the "Could not establish a connection." error message:

72:	
73:	  for i, dialect in pairs(smb2.dialects()) do
74:	    -- we need a clean connection for each negotiate request
75:	    status, smbstate = smb.start(host)
76:	    if(status == false) then
77:	      stdnse.debug1("Could not establish a connection.")
78:	      return nil
79:	    end
80:	    -- We set our overrides Dialects table with the dialect we are testing
81:	    overrides['Dialects'] = {dialect}
82:	    status = smb2.negotiate_v2(smbstate, overrides)