local shortport = require "shortport" local smtp = require "smtp" local stdnse = require "stdnse" local string = require "string" local table = require "table" description = [[ Attempts to use EHLO and HELP to gather the Extended commands supported by an SMTP server. ]] --- -- @usage -- nmap --script smtp-commands.nse [--script-args smtp-commands.domain=] -pT:25,465,587 -- -- @output -- 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 -- -- @args smtp.domain or smtp-commands.domain Define the domain to be used in the SMTP commands. -- changelog -- 1.1.0.0 - 2007-10-12 -- + added HELP command in addition to EHLO -- 1.2.0.0 - 2008-05-19 -- + made output single line, comma-delimited, instead of -- CR LF delimited on multi-lines -- + was able to use regular text and not hex codes -- 1.3.0.0 - 2008-05-21 -- + more robust handling of problems -- + uses verbosity and debugging to decide if you need to -- see certain errors and if the output is in a line or -- in , for lack of a better word, fancy format -- + I am not able to do much testing because my new ISP blocks -- traffic going to port 25 other than to their mail servers as -- a "security" measure. -- 1.3.1.0 - 2008-05-22 -- + minor tweaks to get it working when one of the requests fails -- but not both of them. -- 1.5.0.0 - 2008-08-15 -- + updated to use the nsedoc documentation system -- 1.6.0.0 - 2008-10-06 -- + Updated gsubs to handle different formats, pulls out extra spaces -- and normalizes line endings -- 1.7.0.0 - 2008-11-10 -- + Better normalization of output, remove "250 " from EHLO output, -- don't comma-separate HELP output. -- 2.0.0.0 - 2010-04-19 -- + Complete rewrite based off of Arturo 'Buanzo' Busleiman's SMTP open -- relay detector script. -- 2.0.1.0 - 2010-04-27 -- + Incorporated advice from Duarte Silva (http://seclists.org/nmap-dev/2010/q2/277) -- - 'domain' can be specified via a script-arg -- - removed extra EHLO command that was redundant and not needed -- - fixed two quit()s to include a return value -- + To reiterate, this is a blatant cut and paste job of Arturo 'Buanzo' -- Busleiman's SMTP open relay detector script and Duarte Silva's SMTP -- user enumeration script. -- Props to them for doing what they do and letting me ride on their coattails. -- 2.1.0.0 - 2011-06-01 -- + Rewrite the script to use the smtp.lua library. author = "Jasey DePriest" license = "Same as Nmap--See https://nmap.org/book/man-legal.html" categories = {"default", "discovery", "safe"} portrule = shortport.port_or_service({ 25, 465, 587 }, { "smtp", "smtps", "submission" }) function go(host, port) local options = { timeout = 10000, recv_before = true, ssl = true, } local domain = stdnse.get_script_args('smtp-commands.domain') or smtp.get_domain(host) local result, status = {} -- Try to connect to server. local socket, response = smtp.connect(host, port, options) if not socket then return false, string.format("Couldn't establish connection on port %i", port.number) end status, response = smtp.ehlo(socket, domain) if not status then return status, response end response = response:gsub("\r", "") -- switch to simple LF line termination :gsub("^%s*(.-)%s*$", "%1") -- trim leading and trailing whitespace :gsub("%f[^\0\n]250[-%s]+", "") -- remove line prefix 250 or 250- :gsub("\n", ", ") -- LF to comma :gsub("%s+", " ") -- get rid of extra spaces table.insert(result,response) status, response = smtp.help(socket) if status then response = response:gsub("\r", "") -- switch to simple LF line termination :gsub("^%s*(.-)%s*$", "%1") -- trim leading and trailing whitespace :gsub("%f[^\0\n]214[-%s]+", "") -- remove line prefix 214 or 214- :gsub("%s+", " ") -- get rid of extra spaces table.insert(result,response) smtp.quit(socket) end return true, result end action = function(host, port) local status, result = go(host, port) -- The go function returned false, this means that the result is a simple error message. if not status then return result else if #result > 0 then local final = {} for index, test in ipairs(result) do table.insert(final, test) end return table.concat(final, "\n ") end end end