description = [[ Checks for a vulnerability in IIS 5.1/6.0 that allows arbitrary users to access secured WebDAV folders by searching for a password-protected folder and attempting to access it. This vulnerability was patched in Microsoft Security Bulletin MS09-020 . A list of well known folders (almost 900) is used by default. Each one is checked, and if returns an authentication request (401), another attempt is tried with the malicious encoding. If that attempt returns a successful result (207), then the folder is marked as vulnerable. This script is based on the Metasploit modules/auxiliary/scanner/http/wmap_dir_webdav_unicode_bypass.rb auxiliary module. For more information on this vulnerability and script, see: * http://blog.zoller.lu/2009/05/iis-6-webdac-auth-bypass-and-data.html * http://seclists.org/fulldisclosure/2009/May/att-0134/IIS_Advisory_pdf * http://www.skullsecurity.org/blog/?p=271 * http://www.kb.cert.org/vuls/id/787932 * http://www.microsoft.com/technet/security/advisory/971492.mspx ]] --- -- @usage -- nmap --script http-iis-webdav-vuln -p80,8080 -- -- @output -- 80/tcp open http syn-ack -- |_ http-iis-webdav-vuln: WebDAV is ENABLED. Vulnerable folders discovered: /secret, /webdav -- -- @args webdavfolder Selects a single folder to use, instead of using a built-in list -- @args folderdb The filename of an alternate list of folders. -- @args basefolder The folder to start in; eg, "/web" will try "/web/xxx" ----------------------------------------------------------------------- author = "Ron Bowes and Andrew Orr" license = "Same as Nmap--See http://nmap.org/book/man-legal.html" categories = {"vuln", "intrusive"} require "http" require "shortport" portrule = shortport.port_or_service({80, 443, 8080}, {"http", "https"}) ---Enumeration for results local enum_results = { VULNERABLE = 1, NOT_VULNERABLE = 2, UNKNOWN = 3 } ---Sends a PROPFIND request to the given host, and for the given folder. Returns a table reprenting a response. local function get_response(host, port, folder) local webdav_req = '' local mod_options = { header = { Host = host.ip, Connection = "close", ["User-Agent"] = "Mozilla/5.0 (compatible; Nmap Scripting Engine; http://nmap.org/book/nse.html)", ["Content-Type"] = "application/xml", }, content = webdav_req } return http.request(host, port, "PROPFIND " .. folder .. " HTTP/1.1\r\n", mod_options) end ---Check a single folder on a single host for the vulnerability. Returns one of the enum_results codes. local function go_single(host, port, folder) local response response = get_response(host, port, folder) if(response.status == 401) then local vuln_response local check_folder stdnse.print_debug(1, "http-iis-webdav-vuln: Found protected folder (401): %s", folder) -- check for IIS 6.0 and 5.1 -- doesn't appear to work on 5.0 -- /secret/ becomes /s%c0%afecret/ check_folder = string.sub(folder, 1, 2) .. "%c0%af" .. string.sub(folder, 3) vuln_response = get_response(host, port, check_folder) if(vuln_response.status == 207) then stdnse.print_debug(1, "http-iis-webdav-vuln: Folder seems vulnerable: %s", folder) return enum_results.VULNERABLE else stdnse.print_debug(1, "http-iis-webdav-vuln: Folder does not seem vulnerable: %s", folder) return enum_results.NOT_VULNERABLE end else if(response['status-line'] ~= nil) then stdnse.print_debug(3, "http-iis-webdav-vuln: Not a protected folder (%s): %s", response['status-line'], folder) elseif(response['status'] ~= nil) then stdnse.print_debug(3, "http-iis-webdav-vuln: Not a protected folder (%s): %s", response['status'], folder) else stdnse.print_debug(3, "http-iis-webdav-vuln: Not a protected folder: %s",folder) end return enum_results.UNKNOWN end end ---Checks a list of possible folders for the vulnerability. Returns a list of vulnerable folders. local function go(host, port) local status, folder local results = {} local is_vulnerable = true local folder_file if(nmap.registry.args.folderdb ~= nil) then folder_file = nmap.fetchfile(nmap.registry.args.folderdb) else folder_file = nmap.fetchfile('nselib/data/folders.lst') end if(folder_file == nil) then return false, "Couldn't find folders.lst (should be in nselib/data)" end local file = io.open(folder_file, "r") if not file then return false, "Couldn't find folders.lst (should be in nselib/data)" end while true do local result local line = file:read() if not line then break end if(nmap.registry.args.basefolder ~= nil) then line = "/" .. nmap.registry.args.basefolder .. "/" .. line else line = "/" .. line end result = go_single(host, port, line) if(result == enum_results.VULNERABLE) then results[#results + 1] = line elseif(result == enum_results.NOT_VULNERABLE) then is_vulnerable = false else end end file:close() return true, results, is_vulnerable end action = function(host, port) -- Start by checking if '/' is protected -- if it is, we can't do the tests local result = go_single(host, port, "/") if(result == enum_results.NOT_VULNERABLE) then stdnse.print_debug(1, "http-iis-webdav-vuln: Root folder is password protected, aborting.") return nmap.verbosity() > 0 and "Could not determine vulnerability, since root folder is password protected" or nil end stdnse.print_debug(1, "http-iis-webdav-vuln: Root folder is not password protected, continuing...") response = get_response(host, port, "/") if(response.status == 501) then -- WebDAV is disabled stdnse.print_debug(1, "http-iis-webdav-vuln: WebDAV is DISABLED (PROPFIND failed).") return nmap.verbosity() > 0 and "WebDAV is DISABLED. Server is not currently vulnerable." or nil else if(response.status == 207) then -- PROPFIND works, WebDAV is enabled stdnse.print_debug(1, "http-iis-webdav-vuln: WebDAV is ENABLED (PROPFIND was successful).") else -- probably not running IIS 5.0/5.1/6.0 if(response['status-line'] ~= nil) then stdnse.print_debug(1, "http-iis-webdav-vuln: PROPFIND request failed with \"%s\".", response['status-line']) elseif(response['status'] ~= nil) then stdnse.print_debug(1, "http-iis-webdav-vuln: PROPFIND request failed with \"%s\".", response['status']) else stdnse.print_debug(1, "http-iis-webdav-vuln: PROPFIND request failed.") end return nmap.verbosity() > 0 and "ERROR: This web server is not supported." or nil end end if(nmap.registry.args.webdavfolder ~= nil) then local folder = nmap.registry.args.webdavfolder local result = go_single(host, port, "/" .. folder) if(result == enum_results.VULNERABLE) then return string.format("WebDAV is ENABLED. Folder is vulnerable: %s", folder) elseif(result == enum_results.NOT_VULNERABLE) then return nmap.verbosity() > 0 and string.format("WebDAV is ENABLED. Folder is NOT vulnerable: %s", folder) or nil else return nmap.verbosity() > 0 and string.format("WebDAV is ENABLED. Could not determine vulnerability of folder: %s", folder) or nil end else local status, results, is_vulnerable = go(host, port) if(status == false) then return nmap.verbosity() > 0 and "ERROR: " .. results or nil else if(#results == 0) then if(is_vulnerable == false) then return nmap.verbosity() > 0 and "WebDAV is ENABLED. Protected folder found but could not be exploited. Server does not appear to be vulnerable." or nil else return nmap.verbosity() > 0 and "WebDAV is ENABLED. No protected folder found; check not run. If you know a protected folder, add --script-args=webdavfolder=" or nil end else return "WebDAV is ENABLED. Vulnerable folders discovered: " .. stdnse.strjoin(", ", results) end end end end