Nmap smtp-commands NSE Script

Script Overview

---

Script source code: https://github.com/nmap/nmap/tree/master/scripts/smtp-commands.nse
Script categories: default, discovery, safe
Target service / protocol: smtp, smtps, submission
Target network port(s): 25, 465, 587
List of CVEs: -

Script Description

---

The smtp-commands.nse script attempts to use EHLO and HELP to gather the Extended commands supported by an SMTP server.

Smtp-commands NSE Script Arguments

---

This is a full list of arguments supported by the smtp-commands.nse script:

smtp.domain

Or smtp-commands.domain Define the domain to be used in the SMTP commands.

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.

- - -
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=smtp-commands --script-args smtp.domain=value,smbdomain=value <target>

Smtp-commands NSE Script Example Usage

---

Here's an example of how to use the smtp-commands.nse script:

nmap --script smtp-commands.nse [--script-args smtp-commands.domain=<domain>] -pT:25,465,587 <host>

Smtp-commands NSE Script Example Output

---

Here's a sample output from the smtp-commands.nse script:

PORT   STATE SERVICE REASON  VERSION
25/tcp open  smtp    syn-ack Microsoft ESMTP 6.0.3790.3959
| smtp-commands: SMTP.domain.com Hello [172.x.x.x], TURN, SIZE, ETRN, PIPELINING, DSN, ENHANCEDSTATUSCODES, 8bitmime, BINARYMIME, CHUNKING, VRFY, X-EXPS GSSAPI NTLM LOGIN, X-EXPS=LOGIN, AUTH GSSAPI NTLM LOGIN, AUTH=LOGIN, X-LINK2STATE, XEXCH50, OK
|_ This server supports the following commands: HELO EHLO STARTTLS RCPT DATA RSET MAIL QUIT HELP AUTH TURN ETRN BDAT VRFY

Smtp-commands 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

---

• Jasey DePriest

References

---

• https://nmap.org/nsedoc/scripts/smtp-commands.html
• https://github.com/nmap/nmap/tree/master/scripts/smtp-commands.nse
• http://seclists.org/nmap-dev/2010/q2/277

See Also

---

Related NSE scripts to the smtp-commands.nse script:

• smtp-brute.nse
• smtp-enum-users.nse
• smtp-ntlm-info.nse
• smtp-open-relay.nse
• smtp-strangeport.nse
• smtp-vuln-cve2010-4344.nse
• smtp-vuln-cve2011-1720.nse
• smtp-vuln-cve2011-1764.nse

Visit Nmap NSE Library for more scripts.

The smtp-commands.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.

Couldn't establish connection on port %i

---

Here is a relevant code snippet related to the "Couldn't establish connection on port %i" error message:

82:	
83:	  local result, status = {}
84:	  -- Try to connect to server.
85:	  local socket, response = smtp.connect(host, port, options)
86:	  if not socket then
87:	    return false, string.format("Couldn't establish connection on port %i",
88:	      port.number)
89:	  end
90:	
91:	  status, response = smtp.ehlo(socket, domain)
92:	  if not status then