cics-user-enum
NSE detection rule by Philip Young aka Soldier of Fortran · Same as Nmap--See https://nmap.org/book/man-legal.html
CICS User ID enumeration script for the CESL/CESN Login screen.
local stdnse = require "stdnse"
local shortport = require "shortport"
local tn3270 = require "tn3270"
local brute = require "brute"
local creds = require "creds"
local unpwdb = require "unpwdb"
local string = require "string"
local stringaux = require "stringaux"
description = [[
CICS User ID enumeration script for the CESL/CESN Login screen.
]]
---
-- @args idlist Path to list of transaction IDs.
-- Defaults to the list of CICS transactions from IBM.
-- @args cics-user-enum.commands Commands in a semi-colon separated list needed
-- to access CICS. Defaults to <code>CICS</code>.
-- @args cics-user-enum.transaction By default this script uses the <code>CESL</code> transaction.
-- on some systems the transactio ID <code>CESN</code> is needed. Use this argument to change the
-- logon transaction ID.
--
-- @usage
-- nmap --script=cics-user-enum -p 23 <targets>
--
-- nmap --script=cics-user-enum --script-args userdb=users.txt,
-- cics-user-enum.commands="exit;logon applid(cics42)" -p 23 <targets>
--
-- @output
-- PORT STATE SERVICE
-- 23/tcp open tn3270
-- | cics-user-enum:
-- | Accounts:
-- | PLAGUE: Valid - CICS User ID
-- |_ Statistics: Performed 31 guesses in 114 seconds, average tps: 0
--
-- @changelog
-- 2016-08-29 - v0.1 - created by Soldier of Fortran
-- 2016-12-19 - v0.2 - Added RACF support
-- 2019-02-01 - v0.3 - Disabled TN3270E support
--
-- @author Philip Young
-- @copyright Same as Nmap--See https://nmap.org/book/man-legal.html
--
author = "Philip Young aka Soldier of Fortran"
license = "Same as Nmap--See https://nmap.org/book/man-legal.html"
categories = {"intrusive", "brute"}
portrule = shortport.port_or_service({23,992}, "tn3270")
Driver = {
new = function(self, host, port, options)
local o = {}
setmetatable(o, self)
self.__index = self
o.host = host
o.port = port
o.options = options
o.tn3270 = tn3270.Telnet:new()
o.tn3270:disable_tn3270e()
return o
end,
connect = function( self )
local status, err = self.tn3270:initiate(self.host,self.port)
self.tn3270:get_screen_debug(2)
if not status then
stdnse.debug("Could not initiate TN3270: %s", err )
return false
end
return true
end,
disconnect = function( self )
self.tn3270:disconnect()
self.tn3270 = nil
return true
end,
login = function (self, user, pass) -- pass is actually the UserID we want to try
local commands = self.options['commands']
local transaction = self.options['trn']
local timeout = 300
local max_blank = 1
local loop = 1
local err
stdnse.debug(2,"Getting to CICS")
local run = stringaux.strsplit(";%s*", commands)
for i = 1, #run do
stdnse.debug(1,"Issuing Command (#%s of %s): %s", i, #run ,run[i])
self.tn3270:send_cursor(run[i])
self.tn3270:get_all_data()
self.tn3270:get_screen_debug(2)
end
-- Are we at the logon transaction?
if not (self.tn3270:find('SIGN ON TO CICS') and self.tn3270:find("Signon to CICS")) then
-- We might be at some weird screen, lets try and exit it then clear it out
stdnse.debug(2,"Sending: F3")
self.tn3270:send_pf(3) -- send F3
self.tn3270:get_all_data()
stdnse.debug(2,"Clearing the Screen")
self.tn3270:send_clear()
self.tn3270:get_all_data()
self.tn3270:get_screen_debug(2)
stdnse.debug(2,"Sending Transaction ID: %s", transaction)
self.tn3270:send_cursor(transaction)
self.tn3270:get_all_data()
-- Have we encoutered a slow system?
if self.tn3270:isClear() then
self.tn3270:get_all_data(1000)
end
self.tn3270:get_screen_debug(2)
end
-- At this point we MUST be at CESL/CESN to try accounts.
-- If we're not then we quit with an error
if not (self.tn3270:find('Type your userid and password')) then
local err = brute.Error:new( "Can't get to Transaction CESN")
err:setRetry( true )
return false, err
end
-- Ok we're good we're at CESL/CESN. Enter the USERID.
stdnse.verbose("Trying User ID: %s", pass)
self.tn3270:send_cursor(pass)
self.tn3270:get_all_data()
stdnse.debug(2,"Screen Received for User ID: %s", pass)
self.tn3270:get_screen_debug(2)
if self.tn3270:find('TSS7145E') or
self.tn3270:find('ACF01004') or
self.tn3270:find('DFHCE3530') then
-- known invalid userid messages
-- TopSecret: TSS7145E
-- ACF2: ACF01004
-- RACF: DFHCE3530
stdnse.debug("Invalid CICS User ID: %s", string.upper(pass))
return false, brute.Error:new( "Incorrect CICS User ID" )
elseif self.tn3270:find('TSS7102E') or
self.tn3270:find('ACF01012') or
self.tn3270:find('DFHCE3523') then
-- TopSecret: TSS7102E Password Missing
-- ACF2: ACF01012 PASSWORD NOT MATCHED
-- RACF: DFHCE3523 Please type your password.
stdnse.verbose("Valid CICS User ID: %s", string.upper(pass))
return true, creds.Account:new("CICS User", string.upper(pass), creds.State.VALID)
else
stdnse.verbose("Valid(?) CICS User ID: %s", string.upper(pass))
-- The user may be valid for another reason, lets store that reason.
stdnse.verbose(2,"User: " .. user .. " MSG:" .. self.tn3270:get_screen():sub(2,80))
return true, creds.Account:new("CICS User: ".. string.upper(pass),'Reason: ' .. self.tn3270:get_screen():sub(2,80), creds.State.VALID)
end
return false, brute.Error:new("Something went wrong, we didn't get a proper response")
end
}
--- Tests the target to see if we can even get to CICS
--
-- @param host host NSE object
-- @param port port NSE object
-- @param commands optional script-args of commands to use to get to CICS
-- @return status true on success, false on failure
local function cics_test( host, port, commands, transaction )
stdnse.verbose(2,"Checking for CICS Login Page")
local tn = tn3270.Telnet:new()
tn:disable_tn3270e()
local status, err = tn:initiate(host,port)
local cesl = false -- initially we're not at CICS
if not status then
stdnse.debug("Could not initiate TN3270: %s", err )
return false
end
tn:get_screen_debug(2) -- prints TN3270 screen to debug
stdnse.debug("Getting to CICS")
local run = stringaux.strsplit(";%s*", commands)
for i = 1, #run do
stdnse.debug(1,"Issuing Command (#%s of %s): %s", i, #run ,run[i])
tn:send_cursor(run[i])
tn:get_all_data()
tn:get_screen_debug(2)
end
tn:get_all_data()
tn:get_screen_debug(2) -- for debug purposes
-- We should now be at CICS. Check if we're already at the logon screen
if tn:find('Type your userid and password') then
stdnse.verbose(2,"At CICS Login Transaction")
tn:disconnect()
return true
end
-- Uh oh. We're not at the logon screen. Now we need to send:
-- * F3 to exit the CICS program
-- * CLEAR (a tn3270 command) to clear the screen.
-- (you need to clear before sending a transaction ID)
-- * a known default CICS transaction ID with predictable outcome
-- (CESF with 'Sign-off is complete.' as the result)
-- to confirm that we were in CICS. If so we return true
-- otherwise we return false
local count = 1
while not tn:isClear() and count < 6 do
-- some systems will just kick you off others are slow in responding
-- this loop continues to try getting out of whatever transaction 5 times. If it can't
-- then we probably weren't in CICS to begin with.
stdnse.debug(2,"Sending: F3")
tn:send_pf(3) -- send F3
tn:get_all_data()
stdnse.debug(2,"Clearing the Screen")
tn:send_clear()
tn:get_all_data()
tn:get_screen_debug(2)
count = count + 1
end
if count == 5 then
return false, 'Could not get to CICS after 5 attempts. Is this even CICS?'
end
stdnse.debug(2,"Sending %s", transaction)
tn:send_cursor(transaction)
tn:get_all_data()
if tn:isClear() then
tn:get_all_data(1000)
end
tn:get_screen_debug(2)
if tn:find('SIGN ON TO CICS') or tn:find("Signon to CICS") then
stdnse.verbose(2,"At CICS Login Transaction (%s)", transaction)
tn:disconnect()
return true
end
tn:disconnect()
return false, 'Could not get to '.. transaction ..' (CICS Logon Screen)'
end
-- Filter iterator for unpwdb
-- IDs are limited to 8 alpha numeric and @, #, $ and can't start with a number
-- pattern:
-- ^%D = The first char must NOT be a digit
-- [%w@#%$] = All letters including the special chars @, #, and $.
local valid_name = function(x)
return (string.len(x) <= 8 and string.match(x,"^%D+[%w@#%$]"))
end
action = function(host, port)
local commands = stdnse.get_script_args(SCRIPT_NAME .. '.commands') or "cics"
local transaction = stdnse.get_script_args(SCRIPT_NAME .. '.transaction') or "CESL"
local cicstst, err = cics_test(host, port, commands, transaction)
if cicstst then
local options = { commands = commands, trn = transaction }
stdnse.debug("Starting CICS User ID Enumeration")
local engine = brute.Engine:new(Driver, host, port, options)
engine.options.script_name = SCRIPT_NAME
engine:setPasswordIterator(unpwdb.filter_iterator(brute.usernames_iterator(),valid_name))
engine.options.passonly = true
engine.options:setTitle("CICS User ID")
local status, result = engine:start()
return result
else
return err
end
end