http-rfi-spider
NSE detection rule by Piotr Olma · Same as Nmap--See https://nmap.org/book/man-legal.html
Crawls webservers in search of RFI (remote file inclusion) vulnerabilities. It
tests every form field it finds and every parameter of a URL containing a
query.
description = [[
Crawls webservers in search of RFI (remote file inclusion) vulnerabilities. It
tests every form field it finds and every parameter of a URL containing a
query.
]]
---
-- @usage
-- nmap --script http-rfi-spider -p80 <host>
--
--
-- @output
-- PORT STATE SERVICE REASON
-- 80/tcp open http
-- | http-rfi-spider:
-- | Possible RFI in form fields
-- | Form "(form 1)" at /experiments/rfihome.html (action rfi.pl) with fields:
-- | inc
-- | Form "someform" at /experiments/rfihome.html (action rfi.pl) with fields:
-- | inc2
-- | Possible RFI in query parameters
-- | Path /experiments/rfi.pl with queries:
-- |_ inc=http%3a%2f%2ftools%2eietf%2eorg%2fhtml%2frfc13%3f
--
-- @xmloutput
-- <table key="Forms">
-- <table key="/experiments/rfihome.html">
-- <table key="(form 1)">
-- <table key="Vulnerable fields">
-- <elem>inc</elem>
-- </table>
-- <elem key="Action">rfi.pl</elem>
-- </table>
-- <table key="someform">
-- <table key="Vulnerable fields">
-- <elem>inc2</elem>
-- </table>
-- <elem key="Action">rfi.pl</elem>
-- </table>
-- </table>
-- </table>
-- <table key="Queries">
-- <table key="/experiments/rfi.pl">
-- <elem>inc=http%3a%2f%2ftools%2eietf%2eorg%2fhtml%2frfc13%3f</elem>
-- </table>
-- </table>
--
-- @args http-rfi-spider.inclusionurl the url we will try to include, defaults
-- to <code>http://tools.ietf.org/html/rfc13?</code>
-- @args http-rfi-spider.pattern the pattern to search for in <code>response.body</code>
-- to determine if the inclusion was successful, defaults to
-- <code>'20 August 1969'</code>
-- @args http-rfi-spider.maxdepth the maximum amount of directories beneath
-- the initial url to spider. A negative value disables the limit.
-- (default: 3)
-- @args http-rfi-spider.maxpagecount the maximum amount of pages to visit.
-- A negative value disables the limit (default: 20)
-- @args http-rfi-spider.url the url to start spidering. This is a URL
-- relative to the scanned host eg. /default.html (default: /)
-- @args http-rfi-spider.withinhost only spider URLs within the same host.
-- (default: true)
-- @args http-rfi-spider.withindomain only spider URLs within the same
-- domain. This widens the scope from <code>withinhost</code> and can
-- not be used in combination. (default: false)
--
author = "Piotr Olma"
license = "Same as Nmap--See https://nmap.org/book/man-legal.html"
categories = {"intrusive"}
local shortport = require 'shortport'
local http = require 'http'
local stdnse = require 'stdnse'
local url = require 'url'
local httpspider = require 'httpspider'
local string = require 'string'
local table = require 'table'
local tableaux = require 'tableaux'
-- this is a variable that will hold the function that checks if a pattern we are searching for is in
-- response's body
local check_response
-- this variable will hold the injection url
local inclusion_url
-- checks if a field is of type we want to check for rfi
local function rfi_field(field_type)
return field_type=="text" or field_type=="radio" or field_type=="checkbox" or field_type=="textarea"
end
-- generates postdata with value of "sampleString" for every field (that satisfies rfi_field()) of a form
local function generate_safe_postdata(form)
local postdata = {}
for _,field in ipairs(form["fields"]) do
if rfi_field(field["type"]) then
postdata[field["name"]] = "sampleString"
end
end
return postdata
end
-- checks each field of a form to see if it's vulnerable to rfi
local function check_form(form, host, port, path)
local vulnerable_fields = {}
local postdata = generate_safe_postdata(form)
local sending_function, response
local form_submission_path = url.absolute(path, form.action)
if form["method"]=="post" then
sending_function = function(data) return http.post(host, port, form_submission_path, nil, nil, data) end
else
sending_function = function(data) return http.get(host, port, form_submission_path.."?"..url.build_query(data), nil) end
end
for _,field in ipairs(form["fields"]) do
if rfi_field(field["type"]) then
stdnse.debug2("checking field %s", field["name"])
postdata[field["name"]] = inclusion_url
response = sending_function(postdata)
if response and response.body and response.status==200 then
if check_response(response.body) then
vulnerable_fields[#vulnerable_fields+1] = field["name"]
end
end
postdata[field["name"]] = "sampleString"
end
end
return vulnerable_fields
end
-- builds urls with a query that would let us decide if a parameter is rfi vulnerable
local function build_urls(injectable)
local new_urls = {}
for _,u in ipairs(injectable) do
if type(u) == "string" then
local parsed_url = url.parse(u)
local old_query = url.parse_query(parsed_url.query)
for f,v in pairs(old_query) do
old_query[f] = inclusion_url
parsed_url.query = url.build_query(old_query)
table.insert(new_urls, url.build(parsed_url))
old_query[f] = v
end
end
end
return new_urls
end
-- as in sql-injection.nse
local function inject(host, port, injectable)
local all = nil
for k, v in pairs(injectable) do
all = http.pipeline_add(v, nil, all, 'GET')
end
return http.pipeline_go(host, port, all)
end
local function check_responses(urls, responses)
if responses == nil or #responses==0 then
return {}
end
local suspects = {}
for i,r in ipairs(responses) do
if r.body then
if check_response(r.body) then
local parsed = url.parse(urls[i])
if suspects[parsed.path] then
table.insert(suspects[parsed.path], parsed.query)
else
suspects[parsed.path] = {}
table.insert(suspects[parsed.path], parsed.query)
end
end
end
end
return suspects
end
portrule = shortport.port_or_service( {80, 443}, {"http", "https"}, "tcp", "open")
function action(host, port)
inclusion_url = stdnse.get_script_args('http-rfi-spider.inclusionurl') or 'http://tools.ietf.org/html/rfc13?'
local pattern_to_search = stdnse.get_script_args('http-rfi-spider.pattern') or '20 August 1969'
-- once we know the pattern we'll be searching for, we can set up the function
check_response = function(body) return string.find(body, pattern_to_search) end
-- create a new crawler instance
local crawler = httpspider.Crawler:new( host, port, nil, { scriptname = SCRIPT_NAME} )
if ( not(crawler) ) then
return
end
local output = stdnse.output_table()
output.Forms = stdnse.output_table()
output.Queries = stdnse.output_table()
while(true) do
local status, r = crawler:crawl()
if ( not(status) ) then
if ( r.err ) then
return stdnse.format_output(false, r.reason)
else
break
end
end
-- first we try rfi on forms
if r.response and r.response.body and r.response.status==200 then
local path = r.url.path
local all_forms = http.grab_forms(r.response.body)
for seq, form_plain in ipairs(all_forms) do
local form = http.parse_form(form_plain)
if form and form.action then
local vulnerable_fields = check_form(form, host, port, path)
if #vulnerable_fields > 0 then
local out_form = stdnse.output_table()
out_form["Action"] = form.action
out_form["Vulnerable fields"] = vulnerable_fields
if not output.Forms[path] then output.Forms[path] = stdnse.output_table() end
output.Forms[path][form.id or string.format("(form %d)", seq)] = out_form
end
end
end --for
end --if
-- now try inclusion by query parameters
local injectable = {}
-- search for injectable links (as in sql-injection.nse)
if r.response.status and r.response.body then
local links = httpspider.LinkExtractor:new(r.url, r.response.body, crawler.options):getLinks()
for _,u in ipairs(links) do
local url_parsed = url.parse(u)
if url_parsed.query then
table.insert(injectable, u)
end
end
end
if #injectable > 0 then
local new_urls = build_urls(injectable)
local responses = inject(host, port, new_urls)
local suspects = check_responses(new_urls, responses)
for p, q in pairs(suspects) do
local queries_out = output.Queries[p] or {}
for _, query in ipairs(q) do
queries_out[#queries_out+1] = query
end
output.Queries[p] = queries_out
end
end
end
local text_output = {}
if #output.Forms > 0 then
local rfi = { name = "Possible RFI in form fields" }
for path, forms in pairs(output.Forms) do
for fid, fobj in pairs(forms) do
local out = tableaux.shallow_tcopy(fobj["Vulnerable fields"])
out.name = string.format('Form "%s" at %s (action %s) with fields:',
fid, path, fobj["Action"])
table.insert(rfi, out)
end
end
table.insert(text_output, rfi)
end
if #output.Queries > 0 then
local rfi = { name = "Possible RFI in query parameters" }
for path, queries in pairs(output.Queries) do
local out = tableaux.shallow_tcopy(queries)
out.name = string.format('Path %s with queries:', path)
table.insert(rfi, out)
end
table.insert(text_output, rfi)
end
if #text_output > 0 then
return output, stdnse.format_output(true, text_output)
end
end