description = [[ Checks if a NetBus server is vulnerable to an authentication bypass vulnerability which allows ful access without knowing the password. For example a server running on TCP port 12345 on localhost with this vulnerability is accessible to anyone. An attacker could simply form a connection to the server ( ncat -C 127.0.0.1 12345 ) and login to the service by typing Password;1; into the console. ]] --- -- @usage -- nmap -p 12345 --script netbus-auth-bypass -- -- @output -- 12345/tcp open netbus -- |_netbus-auth-bypass: Vulnerable author = "Toni Ruottu" license = "Same as Nmap--See http://nmap.org/book/man-legal.html" categories = {"auth", "safe", "vuln"} require("nmap") require("stdnse") require("shortport") dependencies = {"netbus-version", "netbus-brute", "netbus-info"} portrule = shortport.port_or_service (12345, "netbus", {"tcp"}) action = function( host, port ) local socket = nmap.new_socket() local status, err = socket:connect(host.ip, port.number) if not status then return end local buffer, _ = stdnse.make_buffer(socket, "\r") buffer() --discard banner -- The first argument of Password is the super-login bit. -- On vulnerable servers any password will do as long as -- we send the super-login bit. Regular NetBus has only -- one password. Thus, if we can login with two different -- passwords using super-login, the server is vulnerable. socket:send("Password;1;\r") --password: empty if buffer() ~= "Access;1" then return end socket:send("Password;1; \r") --password: space if buffer() == "Access;1" then return "Vulnerable" end return "Not vulnerable, but password is empty" end