mirror of
https://github.com/nmap/nmap.git
synced 2025-12-07 13:11:28 +00:00
37 lines
1.1 KiB
Lua
37 lines
1.1 KiB
Lua
id = "Nameserver open recursive queries (CVE-1999-0024) (BID 136, 678)"
|
|
|
|
description = "Checks if a nameserver on UDP/53 allows queries for third-party names. It is expected that recursion will be enabled on your own internal nameservers."
|
|
|
|
author = "Felix Groebert <felix@groebert.org>"
|
|
|
|
license = "Same as Nmap--See http://nmap.org/book/man-legal.html"
|
|
|
|
categories = {"default", "intrusive"}
|
|
|
|
require "bit"
|
|
require "comm"
|
|
require "shortport"
|
|
|
|
portrule = shortport.portnumber(53, "udp")
|
|
|
|
action = function(host, port)
|
|
|
|
-- generate dns query, Transaction-ID 0xdead, www.wikipedia.org (type A, class IN)
|
|
local request = string.char(0xde, 0xad, 0x01, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x03) .. "www" .. string.char(0x09) .. "wikipedia" .. string.char(0x03) .. "org" .. string.char(0x00, 0x00, 0x01, 0x00, 0x01)
|
|
|
|
local status, result = comm.exchange(host, port, request, {proto="udp"})
|
|
|
|
if not status then
|
|
return
|
|
end
|
|
|
|
-- parse response for dns flags
|
|
if (bit.band(string.byte(result,3), 0x80) == 0x80
|
|
and bit.band(string.byte(result,4), 0x85) == 0x80)
|
|
then
|
|
return "Recursion appears to be enabled"
|
|
end
|
|
|
|
return
|
|
end
|