1 files changed, 241 insertions, 0 deletions
diff --git a/scripts/nrpe-enum.nse b/scripts/nrpe-enum.nse
new file mode 100644
index 0000000..3bab7bc
--- /dev/null
+++ b/scripts/nrpe-enum.nse
@@ -0,0 +1,241 @@
+local nmap = require "nmap"
+local shortport = require "shortport"
+local stdnse = require "stdnse"
+local string = require "string"
+local stringaux = require "stringaux"
+local tab = require "tab"
+
+-- -*- mode: lua -*-
+-- vim: set filetype=lua :
+
+description = [[
+Queries Nagios Remote Plugin Executor (NRPE) daemons to obtain information such
+as load averages, process counts, logged in user information, etc.
+
+This script attempts to execute the stock list of commands that are
+enabled. User-supplied arguments are not supported.
+]]
+
+---
+-- @usage
+-- nmap --script nrpe-enum -p 5666 <host>
+--
+-- @args nrpe-enum.cmds A colon-separated list of commands to be executed.
+--
+-- @output
+-- PORT     STATE SERVICE REASON
+-- 5666/tcp open  nrpe    syn-ack
+-- | nrpe-enum:
+-- | Command             State     Response
+-- | check_hda1          CRITICAL  NRPE: Command 'check_hda1' not defined
+-- | check_load          OK        OK - load average: 1.00, 1.00, 1.00|load1=1.000;15.000;30.000;0; load5=1.000;10.000;25.000;0; load15=1.000;5.000;20.000;0;
+-- | check_total_procs   OK        PROCS OK: 5 processes
+-- | check_users         WARNING   USERS WARNING - 2 users currently logged in |users=2;0;10;0
+-- |_check_zombie_procs  OK        PROCS OK: 0 processes with STATE = Z
+
+author = "Mak Kolybabi"
+license = "Same as Nmap--See https://nmap.org/book/man-legal.html"
+categories = {"discovery", "intrusive"}
+
+
+local NRPE_PROTOCOLS = {
+  "ssl",
+  "tcp"
+}
+
+local NRPE_STATES = {
+  [0] = "OK",
+  [1] = "WARNING",
+  [2] ="CRITICAL",
+  [3] = "UNKNOWN"
+}
+
+local NRPE_COMMANDS = {
+  "check_hda1",
+  "check_load",
+  "check_total_procs",
+  "check_users",
+  "check_zombie_procs"
+}
+
+local CRC32_CONSTANTS = {
+  0x00000000, 0x77073096, 0xEE0E612C, 0x990951BA, 0x076DC419, 0x706AF48F,
+  0xE963A535, 0x9E6495A3, 0x0EDB8832, 0x79DCB8A4, 0xE0D5E91E, 0x97D2D988,
+  0x09B64C2B, 0x7EB17CBD, 0xE7B82D07, 0x90BF1D91, 0x1DB71064, 0x6AB020F2,
+  0xF3B97148, 0x84BE41DE, 0x1ADAD47D, 0x6DDDE4EB, 0xF4D4B551, 0x83D385C7,
+  0x136C9856, 0x646BA8C0, 0xFD62F97A, 0x8A65C9EC, 0x14015C4F, 0x63066CD9,
+  0xFA0F3D63, 0x8D080DF5, 0x3B6E20C8, 0x4C69105E, 0xD56041E4, 0xA2677172,
+  0x3C03E4D1, 0x4B04D447, 0xD20D85FD, 0xA50AB56B, 0x35B5A8FA, 0x42B2986C,
+  0xDBBBC9D6, 0xACBCF940, 0x32D86CE3, 0x45DF5C75, 0xDCD60DCF, 0xABD13D59,
+  0x26D930AC, 0x51DE003A, 0xC8D75180, 0xBFD06116, 0x21B4F4B5, 0x56B3C423,
+  0xCFBA9599, 0xB8BDA50F, 0x2802B89E, 0x5F058808, 0xC60CD9B2, 0xB10BE924,
+  0x2F6F7C87, 0x58684C11, 0xC1611DAB, 0xB6662D3D, 0x76DC4190, 0x01DB7106,
+  0x98D220BC, 0xEFD5102A, 0x71B18589, 0x06B6B51F, 0x9FBFE4A5, 0xE8B8D433,
+  0x7807C9A2, 0x0F00F934, 0x9609A88E, 0xE10E9818, 0x7F6A0DBB, 0x086D3D2D,
+  0x91646C97, 0xE6635C01, 0x6B6B51F4, 0x1C6C6162, 0x856530D8, 0xF262004E,
+  0x6C0695ED, 0x1B01A57B, 0x8208F4C1, 0xF50FC457, 0x65B0D9C6, 0x12B7E950,
+  0x8BBEB8EA, 0xFCB9887C, 0x62DD1DDF, 0x15DA2D49, 0x8CD37CF3, 0xFBD44C65,
+  0x4DB26158, 0x3AB551CE, 0xA3BC0074, 0xD4BB30E2, 0x4ADFA541, 0x3DD895D7,
+  0xA4D1C46D, 0xD3D6F4FB, 0x4369E96A, 0x346ED9FC, 0xAD678846, 0xDA60B8D0,
+  0x44042D73, 0x33031DE5, 0xAA0A4C5F, 0xDD0D7CC9, 0x5005713C, 0x270241AA,
+  0xBE0B1010, 0xC90C2086, 0x5768B525, 0x206F85B3, 0xB966D409, 0xCE61E49F,
+  0x5EDEF90E, 0x29D9C998, 0xB0D09822, 0xC7D7A8B4, 0x59B33D17, 0x2EB40D81,
+  0xB7BD5C3B, 0xC0BA6CAD, 0xEDB88320, 0x9ABFB3B6, 0x03B6E20C, 0x74B1D29A,
+  0xEAD54739, 0x9DD277AF, 0x04DB2615, 0x73DC1683, 0xE3630B12, 0x94643B84,
+  0x0D6D6A3E, 0x7A6A5AA8, 0xE40ECF0B, 0x9309FF9D, 0x0A00AE27, 0x7D079EB1,
+  0xF00F9344, 0x8708A3D2, 0x1E01F268, 0x6906C2FE, 0xF762575D, 0x806567CB,
+  0x196C3671, 0x6E6B06E7, 0xFED41B76, 0x89D32BE0, 0x10DA7A5A, 0x67DD4ACC,
+  0xF9B9DF6F, 0x8EBEEFF9, 0x17B7BE43, 0x60B08ED5, 0xD6D6A3E8, 0xA1D1937E,
+  0x38D8C2C4, 0x4FDFF252, 0xD1BB67F1, 0xA6BC5767, 0x3FB506DD, 0x48B2364B,
+  0xD80D2BDA, 0xAF0A1B4C, 0x36034AF6, 0x41047A60, 0xDF60EFC3, 0xA867DF55,
+  0x316E8EEF, 0x4669BE79, 0xCB61B38C, 0xBC66831A, 0x256FD2A0, 0x5268E236,
+  0xCC0C7795, 0xBB0B4703, 0x220216B9, 0x5505262F, 0xC5BA3BBE, 0xB2BD0B28,
+  0x2BB45A92, 0x5CB36A04, 0xC2D7FFA7, 0xB5D0CF31, 0x2CD99E8B, 0x5BDEAE1D,
+  0x9B64C2B0, 0xEC63F226, 0x756AA39C, 0x026D930A, 0x9C0906A9, 0xEB0E363F,
+  0x72076785, 0x05005713, 0x95BF4A82, 0xE2B87A14, 0x7BB12BAE, 0x0CB61B38,
+  0x92D28E9B, 0xE5D5BE0D, 0x7CDCEFB7, 0x0BDBDF21, 0x86D3D2D4, 0xF1D4E242,
+  0x68DDB3F8, 0x1FDA836E, 0x81BE16CD, 0xF6B9265B, 0x6FB077E1, 0x18B74777,
+  0x88085AE6, 0xFF0F6A70, 0x66063BCA, 0x11010B5C, 0x8F659EFF, 0xF862AE69,
+  0x616BFFD3, 0x166CCF45, 0xA00AE278, 0xD70DD2EE, 0x4E048354, 0x3903B3C2,
+  0xA7672661, 0xD06016F7, 0x4969474D, 0x3E6E77DB, 0xAED16A4A, 0xD9D65ADC,
+  0x40DF0B66, 0x37D83BF0, 0xA9BCAE53, 0xDEBB9EC5, 0x47B2CF7F, 0x30B5FFE9,
+  0xBDBDF21C, 0xCABAC28A, 0x53B39330, 0x24B4A3A6, 0xBAD03605, 0xCDD70693,
+  0x54DE5729, 0x23D967BF, 0xB3667A2E, 0xC4614AB8, 0x5D681B02, 0x2A6F2B94,
+  0xB40BBE37, 0xC30C8EA1, 0x5A05DF1B, 0x2D02EF8D
+}
+
+local crc32 = function(s)
+  local crc = 0xFFFFFFFF
+  for i = 1, #s do
+    local p4 = (crc ~ s:byte(i)) & 0xff
+    local p5 = CRC32_CONSTANTS[p4 + 1]
+    crc = p5 ~ (crc >> 8)
+  end
+
+  return crc ~ 0xFFFFFFFF
+end
+
+local nrpe_open = function(host, port)
+  for _, proto in pairs(NRPE_PROTOCOLS) do
+    local sock = nmap.new_socket()
+    sock:set_timeout(2000)
+    local status, err = sock:connect(host, port, proto)
+    if status then
+      NRPE_PROTOCOLS = {proto}
+      return true, sock
+    end
+
+    stdnse.debug2("Can't connect using %s: %s", proto, err)
+    sock:close()
+  end
+
+  return false, nil
+end
+
+local nrpe_write = function(cmd)
+  -- Create request packet, before checksum.
+  local pkt = string.pack(">I2 I2 I4 I2",
+   2,
+   1,
+   0,
+   0)
+   .. cmd
+   .. string.rep("\0", 1024 - #cmd)
+   .. "\0\0"
+
+  -- Calculate the checksum, and insert it into the packet.
+  pkt = pkt:sub(1,4) .. string.pack(">I4", crc32(pkt)) .. pkt:sub(9)
+
+  return pkt
+end
+
+local nrpe_read = function(pkt)
+  local result = {}
+
+  -- Parse packet.
+  result.version,
+  result.type,
+  result.crc32,
+  result.state,
+  result.data = string.unpack(">I2 I2 I4 I2 z", pkt)
+
+  return result
+end
+
+local nrpe_check = function(host, port, cmd)
+  -- Create connection.
+  local status, sock = nrpe_open(host, port)
+  if not status then
+    return false, nil
+  end
+
+  -- Send query.
+  local status, err = sock:send(nrpe_write(cmd))
+  if not status then
+    stdnse.debug1("Failed to send NRPE query for command %s: %s", cmd, err)
+    sock:close()
+    return false, nil
+  end
+
+  -- Receive response.
+  local status, resp = sock:receive()
+  if not status then
+    stdnse.debug1("Can't read NRPE response: %s", resp)
+    sock:close()
+    return false, nil
+  end
+
+  sock:close()
+
+  return true, nrpe_read(resp)
+end
+
+portrule = shortport.port_or_service(5666, "nrpe")
+
+action = function(host, port)
+  -- Get script arguments.
+  local cmds = stdnse.get_script_args("nrpe-enum.cmds")
+  if cmds then
+    cmds = stringaux.strsplit(":", cmds)
+  else
+    cmds = NRPE_COMMANDS
+  end
+
+  -- Create results table.
+  local results = tab.new()
+  tab.addrow(
+  results,
+  "Command",
+  "State",
+  "Response"
+  )
+
+  -- Try each NRPE command, and collect the results.
+  for _, cmd in pairs(cmds) do
+    local status, result = nrpe_check(host, port, cmd)
+    if status then
+      tab.addrow(
+      results,
+      cmd,
+      NRPE_STATES[result.state],
+      result.data
+      )
+    end
+  end
+
+  -- If no queries generated responses, don't output anything.
+  if #results == 1 then
+    return
+  end
+
+  -- Record service description.
+  port.version.name = "nrpe"
+  port.version.product = "Nagios Remote Plugin Executor"
+  nmap.set_port_version(host, port)
+
+  -- Format table, without trailing newline.
+  results = tab.dump(results)
+  results = results:sub(1, #results - 1)
+
+  return "\n" .. results
+end