9.8 High
CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
HIGH
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
10 High
CVSS2
Access Vector
NETWORK
Access Complexity
LOW
Authentication
NONE
Confidentiality Impact
COMPLETE
Integrity Impact
COMPLETE
Availability Impact
COMPLETE
AV:N/AC:L/Au:N/C:C/I:C/A:C
0.974 High
EPSS
Percentile
99.9%
Detects whether a server is vulnerable to the SSL/TLS “CCS Injection” vulnerability (CVE-2014-0224), first discovered by Masashi Kikuchi. The script is based on the ccsinjection.c code authored by Ramon de C Valle (<https://gist.github.com/rcvalle/71f4b027d61a78c42607>)
In order to exploit the vulnerablity, a MITM attacker would effectively do the following:
o Wait for a new TLS connection, followed by the ClientHello ServerHello handshake messages.
o Issue a CCS packet in both the directions, which causes the OpenSSL code to use a zero length pre master secret key. The packet is sent to both ends of the connection. Session Keys are derived using a zero length pre master secret key, and future session keys also share this weakness.
o Renegotiate the handshake parameters.
o The attacker is now able to decrypt or even modify the packets in transit.
The script works by sending a ‘ChangeCipherSpec’ message out of order and checking whether the server returns an ‘UNEXPECTED_MESSAGE’ alert record or not. Since a non-patched server would simply accept this message, the CCS packet is sent twice, in order to force an alert from the server. If the alert type is different than ‘UNEXPECTED_MESSAGE’, we can conclude the server is vulnerable.
See the documentation for the tls library.
See the documentation for the smbauth library.
See the documentation for the mssql library.
See the documentation for the smtp library.
See the documentation for the smb library.
See the documentation for the vulns library.
nmap -p 443 --script ssl-ccs-injection <target>
PORT STATE SERVICE
443/tcp open https
| ssl-ccs-injection:
| VULNERABLE:
| SSL/TLS MITM vulnerability (CCS Injection)
| State: VULNERABLE
| Risk factor: High
| Description:
| OpenSSL before 0.9.8za, 1.0.0 before 1.0.0m, and 1.0.1 before
| 1.0.1h does not properly restrict processing of ChangeCipherSpec
| messages, which allows man-in-the-middle attackers to trigger use
| of a zero-length master key in certain OpenSSL-to-OpenSSL
| communications, and consequently hijack sessions or obtain
| sensitive information, via a crafted TLS handshake, aka the
| "CCS Injection" vulnerability.
|
| References:
| https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2014-0224
| http://www.cvedetails.com/cve/2014-0224
|_ http://www.openssl.org/news/secadv_20140605.txt
local nmap = require('nmap')
local shortport = require('shortport')
local sslcert = require('sslcert')
local stdnse = require('stdnse')
local vulns = require('vulns')
local tls = require 'tls'
local tableaux = require "tableaux"
description = [[
Detects whether a server is vulnerable to the SSL/TLS "CCS Injection"
vulnerability (CVE-2014-0224), first discovered by Masashi Kikuchi.
The script is based on the ccsinjection.c code authored by Ramon de C Valle
(https://gist.github.com/rcvalle/71f4b027d61a78c42607)
In order to exploit the vulnerablity, a MITM attacker would effectively
do the following:
o Wait for a new TLS connection, followed by the ClientHello
ServerHello handshake messages.
o Issue a CCS packet in both the directions, which causes the OpenSSL
code to use a zero length pre master secret key. The packet is sent
to both ends of the connection. Session Keys are derived using a
zero length pre master secret key, and future session keys also
share this weakness.
o Renegotiate the handshake parameters.
o The attacker is now able to decrypt or even modify the packets
in transit.
The script works by sending a 'ChangeCipherSpec' message out of order and
checking whether the server returns an 'UNEXPECTED_MESSAGE' alert record
or not. Since a non-patched server would simply accept this message, the
CCS packet is sent twice, in order to force an alert from the server. If
the alert type is different than 'UNEXPECTED_MESSAGE', we can conclude
the server is vulnerable.
]]
---
-- @usage
-- nmap -p 443 --script ssl-ccs-injection <target>
--
-- @output
-- PORT STATE SERVICE
-- 443/tcp open https
-- | ssl-ccs-injection:
-- | VULNERABLE:
-- | SSL/TLS MITM vulnerability (CCS Injection)
-- | State: VULNERABLE
-- | Risk factor: High
-- | Description:
-- | OpenSSL before 0.9.8za, 1.0.0 before 1.0.0m, and 1.0.1 before
-- | 1.0.1h does not properly restrict processing of ChangeCipherSpec
-- | messages, which allows man-in-the-middle attackers to trigger use
-- | of a zero-length master key in certain OpenSSL-to-OpenSSL
-- | communications, and consequently hijack sessions or obtain
-- | sensitive information, via a crafted TLS handshake, aka the
-- | "CCS Injection" vulnerability.
-- |
-- | References:
-- | https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2014-0224
-- | http://www.cvedetails.com/cve/2014-0224
-- |_ http://www.openssl.org/news/secadv_20140605.txt
author = "Claudiu Perta <[email protected]>"
license = "Same as Nmap--See https://nmap.org/book/man-legal.html"
categories = { "vuln", "safe" }
dependencies = {"https-redirect"}
portrule = function(host, port)
return shortport.ssl(host, port) or sslcert.getPrepareTLSWithoutReconnect(port)
end
local Error = {
NOT_VULNERABLE = 0,
CONNECT = 1,
PROTOCOL_MISMATCH = 2,
SSL_HANDSHAKE = 3,
TIMEOUT = 4
}
---
-- Reads an SSL/TLS record and returns true if it's any fatal
-- alert and false otherwise.
local function fatal_alert(s)
local status, buffer = tls.record_buffer(s)
if not status then
return false
end
local position, record = tls.record_read(buffer, 1)
if record == nil then
return false
end
if record.type ~= "alert" then
return false
end
for _, body in ipairs(record.body) do
if body.level == "fatal" then
return true
end
end
return false
end
---
-- Reads an SSL/TLS record and returns true if it's a fatal,
-- 'unexpected_message' alert and false otherwise.
local function alert_unexpected_message(s)
local status, buffer
status, buffer = tls.record_buffer(s, buffer, 1)
if not status then
return false
end
local position, record = tls.record_read(buffer, 1)
if record == nil then
return false
end
if record.type ~= "alert" then
-- Mark this as VULNERABLE, we expect an alert record
return true,true
end
for _, body in ipairs(record.body) do
if body.level == "fatal" and body.description == "unexpected_message" then
return true,false
end
end
return true,true
end
local function test_ccs_injection(host, port, version)
local hello = tls.client_hello({
["protocol"] = version,
-- Only negotiate SSLv3 on its own;
-- TLS implementations may refuse to answer if SSLv3 is mentioned.
["record_protocol"] = (version == "SSLv3") and "SSLv3" or "TLSv1.0",
-- 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),
},
})
local status, err
local s
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 false, Error.CONNECT
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 false, Error.CONNECT
end
end
-- Set a sufficiently large timeout
s:set_timeout(10000)
-- 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 false, Error.CONNECT
end
-- Read response
local done = false
local i = 1
local response
repeat
status, response, err = tls.record_buffer(s, response, i)
if err == "TIMEOUT" or not status then
stdnse.verbose1("No response from server: %s", err)
s:close()
return false, Error.TIMEOUT
end
local record
i, record = tls.record_read(response, i)
if record == nil then
stdnse.debug1("Unknown response from server")
s:close()
return false, Error.NOT_VULNERABLE
elseif record.protocol ~= version then
stdnse.debug1("Protocol version mismatch (%s)", version)
s:close()
return false, Error.PROTOCOL_MISMATCH
elseif record.type == "alert" then
for _, body in ipairs(record.body) do
if body.level == "fatal" then
stdnse.debug1("Fatal alert: %s", body.description)
-- Could be something else, but this lets us retry
return false, Error.PROTOCOL_MISMATCH
end
end
end
if record.type == "handshake" then
for _, body in ipairs(record.body) do
if body.type == "server_hello_done" then
stdnse.debug1("Handshake completed (%s)", version)
done = true
end
end
end
until done
-- Send the change_cipher_spec message twice to
-- force an alert in the case the server is not
-- patched.
-- change_cipher_spec message
local ccs = tls.record_write(
"change_cipher_spec", version, "\x01")
-- Send the first ccs message
status, err = s:send(ccs)
if not status then
stdnse.debug1("Couldn't send first ccs message: %s", err)
s:close()
return false, Error.SSL_HANDSHAKE
end
-- Optimistically read the first alert message
-- Shorter timeout: we expect most servers will bail at this point.
s:set_timeout(stdnse.get_timeout(host))
-- If we got an alert right away, we can stop right away: it's not vulnerable.
if fatal_alert(s) then
s:close()
return false, Error.NOT_VULNERABLE
end
-- Restore our slow timeout
s:set_timeout(10000)
-- Send the second ccs message
status, err = s:send(ccs)
if not status then
stdnse.debug1("Couldn't send second ccs message: %s", err)
s:close()
return false, Error.SSL_HANDSHAKE
end
-- Read the alert message
local vulnerable
status,vulnerable = alert_unexpected_message(s)
-- Leave the target not vulnerable in case of an error. This could occur
-- when running against a different TLS/SSL implementations (e.g., GnuTLS)
if not status then
stdnse.debug1("Couldn't get reply from the server (probably not OpenSSL)")
s:close()
return false, Error.SSL_HANDSHAKE
end
if not vulnerable then
stdnse.debug1("Server returned UNEXPECTED_MESSAGE alert, not vulnerable")
s:close()
return false, Error.NOT_VULNERABLE
else
stdnse.debug1("Vulnerable - alert is not UNEXPECTED_MESSAGE")
s:close()
return true
end
end
action = function(host, port)
local vuln_table = {
title = "SSL/TLS MITM vulnerability (CCS Injection)",
state = vulns.STATE.NOT_VULN,
risk_factor = "High",
description = [[
OpenSSL before 0.9.8za, 1.0.0 before 1.0.0m, and 1.0.1 before 1.0.1h
does not properly restrict processing of ChangeCipherSpec messages,
which allows man-in-the-middle attackers to trigger use of a zero
length master key in certain OpenSSL-to-OpenSSL communications, and
consequently hijack sessions or obtain sensitive information, via
a crafted TLS handshake, aka the "CCS Injection" vulnerability.
]],
references = {
'https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2014-0224',
'http://www.cvedetails.com/cve/2014-0224',
'http://www.openssl.org/news/secadv_20140605.txt'
}
}
local report = vulns.Report:new(SCRIPT_NAME, host, port)
-- client hello will support multiple versions of TLS. We only retry to fall
-- back to SSLv3, which some implementations won't allow in combination with
-- newer versions.
for _, tls_version in ipairs({"TLSv1.2", "SSLv3"}) do
local vulnerable, err = test_ccs_injection(host, port, tls_version)
-- Return an explicit message in case of a TIMEOUT,
-- to avoid considering this as not vulnerable.
if err == Error.TIMEOUT then
return "No reply from server (TIMEOUT)"
end
if err ~= Error.PROTOCOL_MISMATCH then
if vulnerable then
vuln_table.state = vulns.STATE.VULN
end
break
end
end
return report:make_output(vuln_table)
end
9.8 High
CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
HIGH
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
10 High
CVSS2
Access Vector
NETWORK
Access Complexity
LOW
Authentication
NONE
Confidentiality Impact
COMPLETE
Integrity Impact
COMPLETE
Availability Impact
COMPLETE
AV:N/AC:L/Au:N/C:C/I:C/A:C
0.974 High
EPSS
Percentile
99.9%