id = "SMB Security" description = [[ Returns information about the SMB security level determined by SMB. Here is how to interpret the output: User-level security: Each user has a separate username/password that is used to log into the system. This is the default setup of pretty much everything these days. Share-level security: The anonymous account should be used to log in, then the password is given (in plaintext) when a share is accessed. All users who have access to the share use this password. This was the original way of doing things, but isn't commonly seen, now. If a server uses share-level security, it is vulnerable to sniffing. Challenge/response passwords: If enabled, the server can accept any type of password: * Plaintext * LM and NTLM * LMv2 and NTLMv2 If it isn't set, the server can only accept plaintext passwords. Most servers are configured to use challenge/response these days. If a server is configured to accept plaintext passwords, it is vulnerable to sniffing. LM and NTLM are fairly secure, although there are some bruteforce attacks against them. Message signing: If required, all messages between the client and server must sign be signed by a shared key, derived from the password and the server challenge. If supported and not required, message signing is negotiated between clients and servers and used if both support and request it. By default, Windows clients don't sign messages, so if message signing isn't required by the server, messages probably won't be signed; additionally, if performing a man-in-the-middle attack, an attacker can negotiate no message signing. If message signing isn't required, the server is vulnerable to man-in-the-middle attacks. See nselib/smb.lua for more information on the protocol itself. This script will allow you to use smb arguments (username/password), but it probably won't ever require them. ]] --- --@usage -- nmap --script smb-security-mode.nse -p445 127.0.0.1 -- sudo nmap -sU -sS --script smb-security-mode.nse -p U:137,T:139 127.0.0.1 -- --@output -- | SMB Security: User-level authentication -- | SMB Security: Challenge/response passwords supported -- |_ SMB Security: Message signing supported -- --@args smbusername The SMB username to log in with. The form DOMAIN\username and username@DOMAIN -- are NOT understood. To set a domain, use the smbdomain argument. --@args smbdomain The domain to log in with. If you aren't in a domained environment, then anything -- will (should?) be accepted by the server. --@args smbpassword The password to connect with. Be cautious with this, since some servers will lock -- accounts if the incorrect password is given (although it's rare for the -- 'administrator' account to be lockoutable, in the off chance that it is, you could -- get yourself in trouble). --@args smbhash A password hash to use when logging in. This is given as a single hex string (32 -- characters) or a pair of hex strings (2 x 32 characters, optionally separated by a -- single character). These hashes are the Lanman or NTLM hash of the user's password, -- and are stored by systems, on the harddrive or memory. They can be retrived from memory -- using the fgdump or pwdump tools. --@args smbguest If this is set to 'true' or '1', a 'guest' login will be attempted if the normal one -- fails. This should be harmless, but I thought I would disable it by default anyway -- because I'm not entirely sure of any possible consequences. --@args smbtype The type of SMB authentication to use. By default, NTLMv1 is used, which is a pretty -- decent compromise between security and compatibility. If you are paranoid, you might -- want to use 'v2' or 'lmv2' for this (actually, if you're paranoid, you should be -- avoiding this protocol altogether :P). If you're using an extremely old system, you -- might need to set this to 'v1' or 'lm', which are less secure but more compatible. -- -- If you want finer grained control, these are the possible options: -- * v1 -- Sends LMv1 and NTLMv1 -- * LMv1 -- Sends LMv1 only -- * NTLMv1 -- Sends NTLMv1 only (default) -- * v2 -- Sends LMv2 and NTLMv2 -- * LMv2 -- Sends LMv2 only -- ----------------------------------------------------------------------- author = "Ron Bowes" license = "Same as Nmap--See http://nmap.org/book/man-legal.html" categories = {"discovery", "safe"} require 'smb' --- Check whether or not this script should be run. hostrule = function(host) local port = smb.get_port(host) if(port == nil) then return false else return true end end action = function(host) local state local status, err status, state = smb.start(host) if(status == false) then if(nmap.debugging() > 0) then return "ERROR: " .. state else return nil end end status, err = smb.negotiate_protocol(state) if(status == false) then smb.stop(state) if(nmap.debugging() > 0) then return "ERROR: " .. err else return nil end end local security_mode = state['security_mode'] local response = "" -- User-level authentication or share-level authentication if(bit.band(security_mode, 1) == 1) then response = response .. "User-level authentication\n" else response = response .. " Share-level authentication\n" end -- Challenge/response supported? if(bit.band(security_mode, 2) == 0) then response = response .. "SMB Security: Plaintext only\n" else response = response .. "SMB Security: Challenge/response passwords supported\n" end -- Message signing supported/required? if(bit.band(security_mode, 8) == 8) then response = response .. "SMB Security: Message signing required\n" elseif(bit.band(security_mode, 4) == 4) then response = response .. "SMB Security: Message signing supported\n" else response = response .. "SMB Security: Message signing not supported\n" end smb.stop(state) return response end