cics-enum
NSE detection rule by Philip Young aka Soldier of Fortran · Same as Nmap--See https://nmap.org/book/man-legal.html
CICS transaction ID enumerator for IBM mainframes.
This script is based on mainframe_brute by Dominic White
(https://github.com/sensepost/mainframe_brute). However, this script
doesn't rely on any third party libraries or tools and instead uses
the NSE TN3270 library which emulates a TN3270 screen in lua.
CICS only allows for 4 byte transaction IDs, that is the only specific rule
found for CICS transaction IDs.
local nmap = require "nmap"
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 io = require "io"
local table = require "table"
local string = require "string"
local stringaux = require "stringaux"
description = [[
CICS transaction ID enumerator for IBM mainframes.
This script is based on mainframe_brute by Dominic White
(https://github.com/sensepost/mainframe_brute). However, this script
doesn't rely on any third party libraries or tools and instead uses
the NSE TN3270 library which emulates a TN3270 screen in lua.
CICS only allows for 4 byte transaction IDs, that is the only specific rule
found for CICS transaction IDs.
]]
---
-- @args idlist Path to list of transaction IDs.
-- Defaults to the list of CICS transactions from IBM.
-- @args cics-enum.commands Commands in a semi-colon separated list needed
-- to access CICS. Defaults to <code>CICS</code>.
-- @args cics-enum.path Folder used to store valid transaction id 'screenshots'
-- Defaults to <code>None</code> and doesn't store anything.
-- @args cics-enum.user Username to use for authenticated enumeration
-- @args cics-enum.pass Password to use for authenticated enumeration
--
-- @usage
-- nmap --script=cics-enum -p 23 <targets>
--
-- nmap --script=cics-enum --script-args=idlist=default_cics.txt,
-- cics-enum.command="exit;logon applid(cics42)",
-- cics-enum.path="/home/dade/screenshots/",cics-enum.noSSL=true -p 23 <targets>
--
-- @output
-- PORT STATE SERVICE
-- 23/tcp open tn3270
-- | cics-enum:
-- | Accounts:
-- | CBAM: Valid - CICS Transaction ID
-- | CETR: Valid - CICS Transaction ID
-- | CEST: Valid - CICS Transaction ID
-- | CMSG: Valid - CICS Transaction ID
-- | CEDA: Valid - CICS Transaction ID
-- | CEDF: Potentially Valid - CICS Transaction ID
-- | DSNC: Valid - CICS Transaction ID
-- |_ Statistics: Performed 31 guesses in 114 seconds, average tps: 0
--
-- @changelog
-- 2015-07-04 - v0.1 - created by Soldier of Fortran
-- 2015-11-14 - v0.2 - rewrote iterator
-- 2017-01-22 - v0.3 - added authenticated CICS ID enumeration
-- 2019-02-01 - v0.4 - Removed TN3270E support (breaks location)
--
-- @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")
--- Saves the Screen generated by the CICS command to disk
--
-- @param filename string containing the name and full path to the file
-- @param data contains the data
-- @return status true on success, false on failure
-- @return err string containing error message if status is false
local function save_screens( filename, data )
local f = io.open( filename, "w")
if not f then return false, ("Failed to open file (%s)"):format(filename) end
if not(f:write(data)) then return false, ("Failed to write file (%s)"):format(filename) end
f:close()
return true
end
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 CICS transaction we want to try
local commands = self.options['key1']
local path = self.options['key2']
local cics_user = self.options['user']
local cics_pass = self.options['pass']
local timeout = 300
local max_blank = 1
local loop = 1
local err, status
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
while self.tn3270:isClear() and max_blank < 7 do
stdnse.debug(2, "Screen is not clear for %s. Reading all data with a timeout of %s. Count %s",pass, timeout, max_blank)
self.tn3270:get_all_data(timeout)
timeout = timeout + 100
max_blank = max_blank + 1
end
while not self.tn3270:isClear() and loop < 10 do
-- by this point we're at *some* CICS transaction
-- so we send F3 to exit it
stdnse.debug(2,"Sending: F3")
self.tn3270:send_pf(3) -- send F3
self.tn3270:get_all_data()
self.tn3270:get_screen_debug(2)
-- now we want to clear the screen
self.tn3270:send_clear()
self.tn3270:get_all_data()
stdnse.debug(2,"Current CLEARed Screen. Loop: %s", loop )
self.tn3270:get_screen_debug(2)
loop = loop + 1
end
if loop == 10 then
-- something is wrong but we can still try transactions. Print error to debug.
stdnse.debug('Error. Failed to get to a blank screen under CICS (sending F3 followed by CLEAR). Try lowering maxthreads to fix.')
end
-- If username/password provided try to authenticate first
if not (cics_user == nil and cics_pass == nil) then -- We're doing authenticated CICS testing now baby!
stdnse.debug(2,'Logging in with %s / %s for auth testing', cics_user, cics_pass)
self.tn3270:send_cursor('CESN')
self.tn3270:get_all_data()
self.tn3270:get_screen_debug(2)
local fields = self.tn3270:writeable() -- Get the writeable field areas
local user_loc = {fields[1][1],cics_user} -- This is the 'UserID:' field
local pass_loc = {fields[3][1],cics_pass} -- This is the 'Password:' field ([2] is a group ID)
stdnse.debug(2,'Trying CICS: %s : %s', user, pass)
self.tn3270:send_locations({user_loc,pass_loc})
self.tn3270:get_all_data()
stdnse.debug(2,"Screen Received for User ID: %s / %s", user, pass)
self.tn3270:get_screen_debug(2)
local count = 1
while not self.tn3270:find('DFHCE3549') and count < 6 do -- some systems show a message for a bit before we get to CICS again
self.tn3270:get_all_data(1000) -- loop for 6 seconds
count = count + 1
end
end
self.tn3270:get_screen_debug(2)
self.tn3270:send_clear()
self.tn3270:get_all_data()
self.tn3270:get_screen_debug(2)
stdnse.verbose("Trying Transaction ID: %s", pass)
self.tn3270:send_cursor(pass)
self.tn3270:get_all_data()
max_blank = 1
while self.tn3270:isClear() and max_blank < 7 do
stdnse.debug(2, "Screen is not clear for %s. Reading all data with a timeout of %s. Count %s",pass, timeout, max_blank)
self.tn3270:get_all_data(timeout)
timeout = timeout + 100
max_blank = max_blank + 1
end
stdnse.debug(2,"Screen Received for Transaction ID: %s", pass)
self.tn3270:get_screen_debug(2)
if self.tn3270:find('not recognized') or self.tn3270:find('DFHAC2002') then -- known invalid command
stdnse.debug("Invalid CICS Transaction ID: %s", string.upper(pass))
return false, brute.Error:new( "Incorrect CICS Transaction ID" )
elseif self.tn3270:isClear() then
stdnse.debug(2,"Empty Screen when we expect an error.")
-- this can mean that the transaction ID was valid
-- but it didn't send a screen update so you should check by hand.
-- We're not dumping this screen to disk because it's blank.
return true, creds.Account:new("CICS ID [blank screen]", string.upper(pass), creds.State.VALID)
elseif self.tn3270:find('Unauthorized') or self.tn3270:find('DFHAC2002') then
-- this is a VALID cics transaction but you must be authenticated to used it
-- This will be the same screen for each so we dont bother saving it either
stdnse.verbose("Valid CICS Transaction ID [requires auth]: %s", string.upper(pass))
return true, creds.Account:new("CICS ID [requires auth]", string.upper(pass), creds.State.VALID)
elseif self.tn3270:find('DFHAC2008') or self.tn3270:find('DFHAC2206') or self.tn3270:find('DFHAC2028') or
self.tn3270:find('DFHRT4415') or self.tn3270:find('DFHRT4480') or self.tn3270:find('TSS7254E') then
-- these are technically valid CICS transactions
-- but they are of little/no value. If verbosity is turned way up we'll return these/save a screenshot
-- otherwise there's no point
-- DFHAC2008 -- TranID has been Disabled
-- DFHAC2206 -- Abend
-- DFHRT4415 -- Cannot access through terminal
-- DFHRT4480 -- No Longer Supported
-- DFHAC2028 -- cannot be used
-- TSS7254E -- Access not available through this facility
stdnse.verbose("Valid CICS Transaction ID [Abbend or ID Disabled]: %s", string.upper(pass))
if nmap.verbosity() > 3 then
if path ~= nil then
stdnse.verbose(2,"Writting screen to: %s", path..string.upper(pass)..".txt")
status, err = save_screens(path..string.upper(pass)..".txt",self.tn3270:get_screen())
if not status then
stdnse.verbose(2,"Failed writting screen to: %s", path..string.upper(pass)..".txt")
end
end
return true, creds.Account:new("CICS ID [Abbend]", string.upper(pass), creds.State.VALID)
else
return false, brute.Error:new( "Correct Transaction ID - Access Denied" )
end
elseif not (cics_user == nil and cics_pass == nil) and
(self.tn3270:find('TSS7251E') or self.tn3270:find('DFHAC2033')) then
-- We've logged on but we don't have access to this transaction
-- TSS7251E : Access Denied to PROGRAM <X>
-- DFHAC2033 : You are not authorized to use transaction <X>
stdnse.verbose("Valid CICS Transaction ID [Access Denied]: %s", string.upper(pass))
if nmap.verbosity() > 3 then
return true, creds.Account:new("CICS ID [Access Denied]", string.upper(pass), creds.State.VALID)
else
return false, brute.Error:new( "Correct Transaction ID - Access Denied" )
end
else
stdnse.verbose("Valid CICS Transaction ID: %s", string.upper(pass))
if path ~= nil then
stdnse.verbose(2,"Writting screen to: %s", path..string.upper(pass)..".txt")
status, err = save_screens(path..string.upper(pass)..".txt",self.tn3270:get_screen())
if not status then
stdnse.verbose(2,"Failed writting screen to: %s", path..string.upper(pass)..".txt")
end
end
return true, creds.Account:new("CICS ID", string.upper(pass), 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 user CICS userID
-- @param pass CICS userID password
-- @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, user, pass )
stdnse.debug("Checking for CICS")
local tn = tn3270.Telnet:new()
tn:disable_tn3270e()
local status, err = tn:initiate(host,port)
local msg = 'Unable to get to CICS'
local cics = false -- initially we're not at CICS
if not status then
stdnse.debug("Could not initiate TN3270: %s", err )
return cics
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 technically be at CICS. So we 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 CICS 6 times. If it can't
-- then we probably weren't in CICS to begin with.
if tn:find("Signon") then
stdnse.debug(2,"Found 'Signon' sending PF3")
tn:send_pf(3)
tn:get_all_data()
end
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 == 6 then
return cics
end
stdnse.debug(2,"Sending CESF (CICS Default Sign-off)")
tn:send_cursor('CESF')
tn:get_all_data()
if tn:isClear() then
tn:get_all_data(1000)
end
tn:get_screen_debug(2)
if tn:find('off is complete.') then
cics = true
end
if not (user == nil and pass == nil) then -- We're doing authenticated CICS testing now baby!
stdnse.verbose(2,'Logging in with %s / %s for auth testing', user, pass)
tn:send_clear()
tn:get_all_data()
tn:get_screen_debug(2)
tn:send_cursor('CESN')
tn:get_all_data()
tn:get_screen_debug(2)
local fields = tn:writeable() -- Get the writeable field areas
local user_loc = {fields[1][1],user} -- This is the 'UserID:' field
local pass_loc = {fields[3][1],pass} -- This is the 'Password:' field ([2] is a group ID)
stdnse.verbose('Trying CICS: %s : %s', user, pass)
tn:send_locations({user_loc,pass_loc})
tn:get_all_data()
stdnse.debug(2,"Screen Received for User ID: %s / %s", user, pass)
tn:get_screen_debug(2)
count = 1
while not tn:find('DFHCE3549') and count < 6 do
tn:get_all_data(1000) -- loop for 6 seconds
tn:get_screen_debug(2)
count = count + 1
end
if not tn:find('DFHCE3549') then
cics = false
msg = 'Unable to access CICS with User: '..user..' / Pass: '..pass
else
tn:send_cursor('CESF')
tn:get_all_data()
end
end
tn:disconnect()
return cics,msg
end
-- Filter iterator for unpwdb
-- CICS is limited to 4 characters.
local valid_cics = function(x)
return (string.len(x) <= 4)
end
function iter(t)
local i, val
return function()
i, val = next(t, i)
return val
end
end
action = function(host, port)
local cics_id_file = stdnse.get_script_args("idlist")
local path = stdnse.get_script_args(SCRIPT_NAME .. '.path') -- Folder for screenshots
local commands = stdnse.get_script_args(SCRIPT_NAME .. '.commands') or 'cics'-- VTAM commands/macros to get to CICS
local username = stdnse.get_script_args(SCRIPT_NAME .. '.user') or nil
local password = stdnse.get_script_args(SCRIPT_NAME .. '.pass') or nil
local cics_ids = {"CADP", "CATA", "CATD", "CATR", "CBAM", "CCIN", "CCRL", "CDBC", "CDBD",
"CDBF", "CDBI", "CDBM", "CDBN", "CDBO", "CDBQ", "CDBT", "CDFS", "CDST",
"CDTS", "CEBR", "CEBT", "CECI", "CECS", "CEDA", "CEDB", "CEDC", "CEDF",
"CEDX", "CEGN", "CEHP", "CEHS", "CEKL", "CEMN", "CEMT", "CEOT", "CEPD",
"CEPF", "CEPH", "CEPM", "CEPQ", "CEPS", "CEPT", "CESC", "CESD", "CESF",
"CESL", "CESN", "CEST", "CETR", "CEX2", "CFCL", "CFCR", "CFOR", "CFQR",
"CFQS", "CFTL", "CFTS", "CGRP", "CHLP", "CIDP", "CIEP", "CIND", "CIS1",
"CIS4", "CISB", "CISC", "CISD", "CISE", "CISM", "CISP", "CISQ", "CISR",
"CISS", "CIST", "CISU", "CISX", "CITS", "CJLR", "CJSA", "CJSL", "CJSR",
"CJTR", "CKAM", "CKBC", "CKBM", "CKBP", "CKBR", "CKCN", "CKDL", "CKDP",
"CKQC", "CKRS", "CKRT", "CKSD", "CKSQ", "CKTI", "CLDM", "CLQ2", "CLR1",
"CLR2", "CLS1", "CLS2", "CLS3", "CLS4", "CMAC", "CMPX", "CMSG", "CMTS",
"COVR", "CPCT", "CPIA", "CPIH", "CPIL", "CPIQ", "CPIR", "CPIS", "CPLT",
"CPMI", "CPSS", "CQPI", "CQPO", "CQRY", "CRLR", "CRMD", "CRMF", "CRPA",
"CRPC", "CRPM", "CRSQ", "CRSR", "CRST", "CRSY", "CRTE", "CRTP", "CRTX",
"CSAC", "CSCY", "CSFE", "CSFR", "CSFU", "CSGM", "CSHA", "CSHQ", "CSHR",
"CSKP", "CSMI", "CSM1", "CSM2", "CSM3", "CSM5", "CSNC", "CSNE", "CSOL",
"CSPG", "CSPK", "CSPP", "CSPQ", "CSPS", "CSQC", "CSRK", "CSRS", "CSSF",
"CSSY", "CSTE", "CSTP", "CSXM", "CSZI", "CTIN", "CTSD", "CVMI", "CWBA",
"CWBG", "CWTO", "CWWU", "CWXN", "CWXU", "CW2A", "CXCU", "CXRE", "CXRT",
"DSNC"} -- Default CICS from https://www-01.ibm.com/support/knowledgecenter/SSGMCP_5.2.0/com.ibm.cics.ts.systemprogramming.doc/topics/dfha726.html
cics_id_file = ( (cics_id_file and nmap.fetchfile(cics_id_file)) or cics_id_file )
if cics_id_file then
for l in io.lines(cics_id_file) do
if not l:match("#!comment:") then
table.insert(cics_ids, l)
end
end
end
local cicstst,msg = cics_test(host, port, commands, username, password)
if cicstst then
local title = 'CICS Transaction IDs'
if not(username == nil and password == nil) then title = 'CICS Transaction IDs for User: '.. username end
local options = { key1 = commands, key2 = path, user = username, pass = password }
stdnse.debug("Starting CICS Transaction ID Enumeration")
if path ~= nil then stdnse.verbose(2,"Saving Screenshots to: %s", path) end
local engine = brute.Engine:new(Driver, host, port, options)
engine.options.script_name = SCRIPT_NAME
engine:setPasswordIterator(unpwdb.filter_iterator(iter(cics_ids), valid_cics))
engine.options.passonly = true
engine.options:setTitle(title)
local status, result = engine:start()
return result
else
return msg
end
end