1 files changed, 144 insertions, 0 deletions
diff --git a/scripts/imap-brute.nse b/scripts/imap-brute.nse
new file mode 100644
index 0000000..3321f6b
--- /dev/null
+++ b/scripts/imap-brute.nse
@@ -0,0 +1,144 @@
+local brute = require "brute"
+local coroutine = require "coroutine"
+local creds = require "creds"
+local imap = require "imap"
+local shortport = require "shortport"
+local stdnse = require "stdnse"
+
+description = [[
+Performs brute force password auditing against IMAP servers using either LOGIN, PLAIN, CRAM-MD5, DIGEST-MD5 or NTLM authentication.
+]]
+
+---
+-- @usage
+-- nmap -p 143,993 --script imap-brute <host>
+--
+-- @output
+-- PORT    STATE SERVICE REASON
+-- 143/tcp open  imap    syn-ack
+-- | imap-brute:
+-- |   Accounts
+-- |     braddock:jules - Valid credentials
+-- |     lane:sniper - Valid credentials
+-- |     parker:scorpio - Valid credentials
+-- |   Statistics
+-- |_    Performed 62 guesses in 10 seconds, average tps: 6
+--
+-- @args imap-brute.auth authentication mechanism to use LOGIN, PLAIN,
+--                       CRAM-MD5, DIGEST-MD5 or NTLM
+
+-- Version 0.1
+-- Created 07/15/2011 - v0.1 - created by Patrik Karlsson <patrik@cqure.net>
+
+
+author = "Patrik Karlsson"
+license = "Same as Nmap--See https://nmap.org/book/man-legal.html"
+categories = {"brute", "intrusive"}
+
+portrule = shortport.port_or_service({143,993}, {"imap","imaps"})
+
+local mech
+
+-- By using this connectionpool we don't need to reconnect the socket
+-- for each attempt.
+ConnectionPool = {}
+
+Driver =
+{
+
+  -- Creates a new driver instance
+  -- @param host table as received by the action method
+  -- @param port table as received by the action method
+  -- @param pool an instance of the ConnectionPool
+  new = function(self, host, port, pool)
+    local o = { host = host, port = port }
+    setmetatable(o, self)
+    self.__index = self
+    return o
+  end,
+
+  -- Connects to the server (retrieves a connection from the pool)
+  connect = function( self )
+    self.helper = ConnectionPool[coroutine.running()]
+    if ( not(self.helper) ) then
+      self.helper = imap.Helper:new( self.host, self.port )
+      self.helper:connect()
+      ConnectionPool[coroutine.running()] = self.helper
+    end
+    return true
+  end,
+
+  -- Attempts to login to the server
+  -- @param username string containing the username
+  -- @param password string containing the password
+  -- @return status true on success, false on failure
+  -- @return brute.Error on failure and creds.Account on success
+  login = function( self, username, password )
+    local status, err = self.helper:login( username, password, mech )
+    if ( status ) then
+      self.helper:close()
+      self.helper:connect()
+      return true, creds.Account:new(username, password, creds.State.VALID)
+    end
+    if ( err:match("^ERROR: Failed to .* data$") ) then
+      self.helper:close()
+      self.helper:connect()
+      local err = brute.Error:new( err )
+      -- This might be temporary, set the retry flag
+      err:setRetry( true )
+      return false, err
+    end
+    return false, brute.Error:new( "Incorrect password" )
+  end,
+
+  -- Disconnects from the server (release the connection object back to
+  -- the pool)
+  disconnect = function( self )
+    return true
+  end,
+
+}
+
+local function fail (err) return stdnse.format_output(false, err) end
+
+action = function(host, port)
+
+  -- Connects to the server and retrieves the capabilities so that
+  -- authentication mechanisms can be determined
+  local helper = imap.Helper:new(host, port)
+  local status = helper:connect()
+  if (not(status)) then return fail("Failed to connect to the server.") end
+  local status, capabilities = helper:capabilities()
+  if (not(status)) then return fail("Failed to retrieve capabilities.") end
+
+  -- check if an authentication mechanism was provided or try
+  -- try them in the mech_prio order
+  local mech_prio = stdnse.get_script_args("imap-brute.auth")
+  mech_prio = ( mech_prio and { mech_prio } ) or
+    { "LOGIN", "PLAIN", "CRAM-MD5", "DIGEST-MD5", "NTLM" }
+
+  -- iterates over auth mechanisms until a valid mechanism is found
+  for _, m in ipairs(mech_prio) do
+    if ( m == "LOGIN" and not(capabilities.LOGINDISABLED)) then
+      mech = "LOGIN"
+      break
+    elseif ( capabilities["AUTH=" .. m] ) then
+      mech = m
+      break
+    end
+  end
+
+  -- if no mechanisms were found, abort
+  if ( not(mech) ) then
+    return fail("No suitable authentication mechanism was found")
+  end
+
+  local engine = brute.Engine:new(Driver, host, port)
+  engine.options.script_name = SCRIPT_NAME
+  local result
+  status, result = engine:start()
+
+  for _, helper in pairs(ConnectionPool) do helper:close() end
+
+  return result
+end